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The emerging role of vascular endothelial growth factor (VEGF) in vascular
homeostasis: lessons from recent trials with anti-VEGF drugs
Shivshankar Thanigaimani1, Ganessan Kichenadasse2, Arduino A Mangoni1,3
1
Department of Clinical Pharmacology, Flinders University, 2Department of Medical
Oncology, Flinders Medical Centre, Adelaide, Australia; 3Division of Applied Medicine,
University of Aberdeen, Aberdeen, United Kingdom.
Corresponding author:
Arduino A Mangoni, Division of Applied Medicine, Section of Translational Medical
Sciences, School of Medicine & Dentistry, University of Aberdeen, Polwarth Building,
Foresterhill, Aberdeen AB25 2ZD, United Kingdom. Tel: +44 1224 553004; Fax: +44 1224
555199; E-mail: a.a.mangoni@abdn.ac.uk
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Abstract
Vascular endothelial growth factor (VEGF) is an endogenous polypeptide that modulates
angiogenesis in normal physiological conditions as well as in cancer. During angiogenesis,
VEGF interacts with several other angiogenic factors, playing an important role in cell
proliferation, differentiation, migration, cell survival, nitric oxide (NO) production, release of
other growth factors and sympathetic innervation. Based on these mechanisms of action,
several anti-VEGF drugs have been developed for cancer treatment.
This review discusses the physiology and interactions of VEGF, its mechanisms of action
and role in modulating vascular homeostasis. It also discusses the adverse cardiovascular
effects of recently developed anti-VEGF drugs for the treatment of various types of cancer. A
critical appraisal of the human studies on these drugs is provided. Furthermore, putative
mechanisms for the onset of hypertension, the most common adverse cardiovascular effect,
are discussed.
Keywords: vascular endothelial growth factor, angiogenesis, endothelium, homeostasis,
cardiotoxicity, hypertension, nitric oxide, clinical trials
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Introduction
The vascular endothelial growth factor (VEGF) is an endothelial cell specific mitogen
[1]. As the cardiovascular system is the first developing organ system [2] initial steps
such as vasculogenesis [3] are vital during the neonatal stages of life. VEGF gene
knockout causes devascularisation during the neonatal stage leading to embryonic
death [4]. VEGF plays a critical role in physiological and pathological angiogenesis [5]
both at the embryonic [6] and at the adult stage [7]. Most angiogenic factors are either
directly or indirectly induced by VEGF since it is the only angiogenic factor present
throughout all the stages of vascular development [8-10]. VEGF signalling regulates
both angiogenesis (formation of blood vessels) and haematopoiesis (formation of blood
cells) [11]. VEGF expression is increased in myeloma compared to normal tissues [12].
Moreover, an increased expression of VEGF in hypoxic conditions triggers tumour
angiogenesis [13, 14]. The important role of VEGF in promoting angiogenesis and cancer
progression is widely established [15].
Over the last few years, increasing evidence has accumulated suggesting that VEGF also
exerts important modulating effects on vascular tone and blood pressure under physiological
circumstances. This review discusses: 1) VEGF physiology, cellular functions and
mechanism of action; 2) current knowledge on the role of VEGF in modulating vascular
homeostasis; and 3) recent data on the detrimental cardiovascular effects of the recently
marketed anti-angiogenic drugs (anti-VEGF) for the treatment of cancer, with a particular
focus on hypertension.
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VEGF family
VEGFs are polypeptide growth factors responsible for the formation and maintenance of
blood vessels. The VEGF family has 7 members: VEGF-A, B, C, D, placental growth factor
(PIGF), VEGF-E and svVEGF of which the first 5 types are encoded in the mammalian
genome [16] (
Figure 1). VEGF-E or viral VEGF is encoded by the parapox orf virus strain NZ7 whereas
svVEGF is a snake venom derived VEGF [17]. VEGFs are homodimer structures with 8
conserved cysteine residues in a monomer peptide [18].
The human VEGF gene is located in chromosome 6p21.3 [19]. It has 8 exons separated by 7
introns with a coding region of approximately 14kb [20]. Alternative exon splicing of the
VEGF gene results in 4 different species of VEGF: 121, 165, 189 and 206. VEGF-121 is a
freely diffusible acidic polypeptide and does not bind to heparin. VEGF-189 and 206 are
highly basic and completely sequestered in the extracellular matrix [21]. VEGF-165 has
intermediate properties which correlate to most of the characteristic of the native VEGF gene
such as basicity, heparin binding and being a homodimeric glycoprotein [21].
VEGF receptors
VEGF receptors include VEGFR1 (Flt-1), VEGFR2 (KDR/Flk-1) and VEGFR3 (Flt-3) [22] (
Figure 1). VEGFR 1 and 2 possess a 1kb [23] and 4 kb [24] flanking region in their
promoter region which are essential for endothelial specific expression. VEGFR1, also
known as Fms like tyrosine-1 (Flt-1), is expressed in 2 forms of mRNA; one is encoded
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for VEGFR1 and the other is encoded for soluble Fms like tyrosine-1 (sFlt-1) [25]. The
VEGF-receptor binding results in activation of a cascade of events and pathways leading to
angiogenesis [26]. VEGF-A binds to VEGFR1 and 2 to regulate proliferation, migration,
and survival of vascular endothelial cells [22]. VEGF-C and D bind to VEGFR3 to regulate
proliferation, migration, and survival of lymphatic endothelial cells [22]. In addition,
VEGF-C and D bind to VEGFR-2 but their effects on vascular endothelial cells have not yet
been studied. VEGF-A is the most studied protein and is an important component responsible
for vasculogenesis from progenitor cells [4]. VEGF-A/VEGFR2 binding increases vascular
permeability [27]. VEGF-B binds only to VEGFR1, its functional activity being 10-fold
weaker than VEGF-A [16]. Deletion of the second domain in VEGFR1 results in abolition
of VEGF-VEGFR2 binding [26]. It could be speculated that VEGFR1 presents VEGF to
VEGFR2 during physiological and pathological conditions. The down production of
VEGFR1 mRNA would result in decreased presentation of VEGF to VEGFR2, thereby
reducing angiogenic activity. In contrast, over expression of VEGFR1 mRNA results in
increased VEGF-VEGFR1 binding instead of increased presentation of VEGF to
VEGFR2. Thus, VEGFR1 modulates VEGF biological activity by affecting its
availability to VEGFR2 for further signal transduction. This is supported by the
postulation that sFlt-1 can be used as a potent inhibitor of VEGF-mediated angiogenesis
in tumour cells [28].
VEGF co-receptors
In addition to tyrosine kinase receptors, VEGF binds to heparin [1], neuropilin-1 [29] and
neuropilin-2 [30]. Neuropilin-1 and 2 (Nrp-1 and 2) are specific receptors for semaphorin
[31]. Semaphorin is responsible for neuronal proliferation [32].
Soluble Flt-1 or sVEGFR1
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Soluble Flt-1 or sVEGFR1 is a spliced soluble form of VEGFR-1 that acts as an inhibitor of
VEGF activity [33]. It blocks the angiogenic action by sequestering to VEGF or
heterodimerising with the extracellular binding region of the VEGFR1 and 2 (Flt-1 and Flk1/KDR) receptors [34]. This in turn blocks the availability of receptor for phosphorylation
and further signal transduction pathways mediating angiogenesis [33-36]. The difference
between VEGFR1 and sFlt-1 is that the sFlt-1 receptor lacks both the transmembrane domain
and the entire intracellular tyrosine kinase containing region both of which are present in the
Flt-1 receptor [37]. Although both receptors have the same specificity and affinity towards
VEGF sFlt-1 cannot induce signal transduction due to the structural differences described
above [33]. VEGFR1 negatively modulates angiogenesis in the early stages of
embryogenesis. This indicates that the physiological role of both Flt-1 and sFlt-1 is to act as a
‘decoy receptor’.
VEGF and major angiogenic factors
In 1968, it was shown that angiogenesis is induced by several tumour-released growth
factors [38]. The major factors regulating angiogenesis and their functions are
described in Table 1 [16].
VEGF and angiopoietin-1 and 2 are important angiogenic factors involved in the
physiological regulation of vascular endothelial cells [39] (Table 1). Angiopoietin-1 [40]
and angiopoietin-2 [41] are pro-angiogenic and anti-angiogenic factors, respectively.
The complementary action of VEGF and angiopoietin-1 are essential for blood vessel
growth. Angiopoietin-1 induces resistance to plasma leakage to ensure cell integrity
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[42]. On the other hand, angiopoietin-2 counteracts the maturation of endothelial cells
by inhibiting the action of angiopoietin-1. Notably angiopoietin-2 has also been shown to
exert pro-angiogenic effects depending on the concentration of VEGF [43]. This
provides insights into the dose-dependent activity of some angiogenic factors in
regulating vascular physiology.
VEGF-A increases platelet derived growth factor-B (PDGF-B) expression whereas
fibroblast growth factor (FGF) increases platelet derived growth factor receptor-β
(PDGFR-β) expression [44]. Pepper et al showed that VEGF-A and PDGF-B have
synergistic effects in promoting neo-angiogenesis [45] (Table 1). Kano et al
demonstrated that this activity occurs through PDGF-B/PDGFR-β signalling [44].
Neuropilin 1 and 2 are indirect angiogenic factors that induce endothelial cell migration
and sprouting through VEGF [46] (Table 1). Matrix metalloproteinase plays an
important role in tumour angiogenesis [47] with specific transcriptional up regulation of
VEGF-A through Src tyrosine kinase activity [48] (Table 1). VEGF induces tissue-type
and urokinase-type plasminogen activator and its inhibitor in a dose-dependent manner
in microvascular endothelial cells. This relates to the balance of protease and its
inhibitors during capillary morphogenesis [49] (Table 1). Thus, VEGF maintains the
required protease balance enabling angiogenesis. VEGF signalling also increases deltalike ligand 4 (DII4) and notch expression while acting upstream in determining the
specification of arterial vessels [50] (Table 1).
VEGF interactions with other vascular factors
VEGF and their receptors induce, and are induced, by several factors and signalling
mechanisms to enable endothelial cell proliferation and to maintain vascular
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haemostasis. Most of their cellular functions are performed through VEGFR2 binding
(Tables 2 and 3; Figure 2). This triggers the PI3-AKT pathway, a critical mediator of
oncogenic signalling [51].
During hypoxic conditions, the hypoxia-inducing factor alpha (HIF-α) protein induces
the translocation of transcriptional factors from the cytoplasm into the nucleus [52].
This results in the release of growth factors such as cytokines [53], interleukins [54] and
VEGF through NF-κB activation [54]. This pathway takes place in a cyclic manner [5255] (
Figure 2 and Table 2). Endothelin is another vascular factor involved in the regulation
of VEGF expression to maintain vascular tone [56] (Table 2). Angiotensin-II regulates
VEGF through the renin-angiotensin system (RAS) induced NF-κB pathway which
results in formation of endothelial cell substrate in the extracellular matrix (Table 2)
[57].
VEGF forms an endothelial substrate of fibrin gel by induction of tissue type
plasminogen activator, resulting in the sprouting of blood vessels in the endothelium [5,
58] (Table 3). Further, it causes leakage of plasma proteins by exerting vasodilating
effects through the induction of the endothelial and inducible forms of nitric oxide
synthase (eNOS and iNOS) via the PI3-Akt pathway [59] (Table 3). During cellular
proliferation, plasma proteins are required to adhere to the endothelial substrate in the
extracellular matrix. This is mediated by VEGF through the induction of adhesion
factors such as vascular cellular adhesion molecule, intercellular adhesion molecule and
E-selectin [60] (Table 3). VEGF-VEGFR2 binding mediates phosphorylation of focal
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adhesion kinase (FAK) to enhance cellular migration via the heat shock protein 90
(HSP90) which maintains the signalling stability and function of FAK [61, 62] (Table 3).
It also activates paxillin along with FAK phosphorylation which recruits stress induced
actin anchoring proteins thereby resulting in VEGF-induced actin reorganisation [61,
63]. Reorganisation of dendritic actin has been demonstrated during cellular migration
and invasion [64]. VEGF-induced actin reorganisation improves cellular migration in
endothelial cells through FAK/paxillin activation [63].
Guanylate cyclase plays a vital role in vasodilation [65, 66] by mediating cGMP
synthesis [67]. Simultaneous nitric oxide (NO) production and increased cGMP levels
regulate vascular tone [68]. MAPK activation is involved in the NO/cGMP cascade [69]
which is responsible for VEGF-induced endothelial cell proliferation [70] (Figure 2).
VEGF activates phospholipase through the MAPK pathway to initiate prostacyclin
synthesis [71]. It also induces vascular permeability via NO and prostacyclin [72].
Therefore it is possible that the vasoactive effects of VEGF are at least partly
coordinated by prostacyclin and NO in an MAPK activated pathway. This is supported
by the fact that a stable prostacyclin analogue stimulates angiogenesis by initiating
neovascularisation during wound healing [73]. Angiogenic factors are required for
capillaries to sprout and organise into a microvascular network on the fibrin clot of a
wound [74]. VEGF induces angiogenic action by recruiting bone marrow derived cells
to accelerate tissue repair [73, 75]. Requirement of angiogenesis during wound healing
support the important physiological role of VEGF in the process. Prostaglandin I2, also
known as prostacyclin, is another important vasodilator that interacts with VEGF in
physiological and pathological conditions [76, 77].
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VEGF and vascular homeostasis
The cardiovascular system is the first organ system to develop and attain a functioning state
in an embryo [2]. Vascularisation is an important process in the development of such system
through the recruitment of endothelial progenitor cells (EPC). This is mediated by
VEGF/VEGFR1 [78] and VEGF/VEGFR2 [79] signalling [80]. VEGF has mitogenic effects
specifically on vascular endothelial cells [5]. It increases the survival capability of cultured
endothelial cells in absence of serum in the culture medium [81]. VEGF triggers the PI3
kinase - AKT pathway through which it increases the expression of anti-apoptotic proteins
[82]. This action of VEGF inhibits apoptosis and acts as a survival factor for endothelial
cells. Endothelial cell function is pivotal for maintaining vascular homeostasis [83].
Under physiological circumstances, vascular haemostasis is a balance between several
vasoconstricting and vasodilating factors. An imbalance between vasoconstriction and
vasodilation leads to disturbance in the maintenance of vascular tone, vessel function and
structure, and facilitates vascular disease states such as hypertension, atherosclerosis and
heart failure [83]. Endothelin is a potent vasoconstrictor derived from endothelial cells [84].
VEGF has inhibitory effects on endothelin in vascular endothelial cells and, in turn,
endothelin has inhibitory effects on VEGF in vascular smooth muscle cells [56]. Since NO
specifically inhibits endothelin, VEGF inhibition of endothelin could be regulated through
VEGF induced NO production. As a result, endothelin interacts with VEGF to maintain the
homeostasis of vascular endothelial cells and vascular tone.
Effects of VEGF on the vasculature
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VEGF-VEGFR2 binding induces vasorelaxation by increasing phospholipase C, protein
kinase C and inositol 1,4,5 triphosphate activity, decreasing intracellular calcium ions and
increasing synthesis/release of endothelial nitric oxide (NO) [85]. Reduction in intracellular
concentration of calcium ions and increase in NO synthesis are vital steps involved in
vasodilation [86]. Higher NO levels respond to VEGF-induced hypotension by reducing
the expression of eNOS [87]. This is likely to be mediated by NO [68] itself and by
prostaglandin I2 [88] through VEGFR2 signalling [78].
Pre-eclampsia, a condition characterised by endothelial dysfunction, hypertension and
proteinuria involves higher serum levels of sFlt-1 or sVEGFR1 [89]. Higher
concentrations of sFlt-1 or sVEGFR1 lead to decreased VEGF availability to VEGFR2 thus
resulting in endothelial dysfunction [89]. In addition to maintaining endothelial cell integrity,
renal VEGF mRNA expression increases in response to hypertension, stress and increased
RAS activity. This is thought to represent a renoprotective effect [90]. During arterial
injury, up-regulation of VEGF facilitates the re-endothelialisation of arterial walls [91]
by mediating PKC activation of NO synthesis [92]. The NO secreted from regenerated
endothelium attenuates VEGF expression in a concentration dependent manner by
inhibiting the binding of PKC initiated transcription factor (activator protein-1) to the
VEGF promoter region [92]. This concept of reciprocal activity between VEGF and NO
indicate their significant role in the maintenance of endothelial cell integrity.
In ischaemic cardiomyopathy with co-existing hypoxia, VEGF mRNA expression is up
regulated with an increase in vascular density [93]. This is likely to occur through induction
of HIF-α. In such conditions, VEGF increases microvascular permeability by inducing
leakage of plasma proteins. Acute topical administration of VEGF results in fenestrated
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endothelial cells and increased vascular permeability [94]. Exaggerated vasorelaxation could
be a response to endothelial and renal dysfunction which impairs baroreceptor function and
decreases VEGF clearance in hypertensive rats [95]. The accumulation of VEGF secondary
to impaired renal clearance in hypertensive rats could possibly have a pronounced effect on
the exaggerated vasorelaxation.
By binding to receptor-1, VEGF initiates vascular sympathetic innervation by improving the
growth of sympathetic axons [96]. VEGF also inhibits semaphorin/Nrp binding and
prevents semaphorin-induced collapse of sympathetic nerves [97]. Semaphorin/Nrp
binding aids in vascular embryonic development [98] by increasing the affinity of
VEGF-A to VEGFR2 and thereby enhancing downstream signal transduction [29].
There is no evidence that semaphorin and/or neuropilin independently induce signal
transduction after VEGF binding. Neuropilin aids in presenting VEGF to its receptor
thereby increasing VEGF activity but does not independently initiate angiogenesis [99].
Vascular sympathetic innervation is an important mediator of blood pressure and blood flow
[100]. Thus, VEGF maintains vascular haemostasis by mediating the physiological balance of
autonomic and cardiovascular systems in addition to maintaining vascular sympathetic
innervation (
Figure 3).
Rationale for anti-angiogenesis in cancer treatment
Judah Folkman proposed anti-angiogenic therapy to inhibit the growth of solid tumours
before the discovery of VEGF [101]. Agents with potential anti-angiogenic effects include
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endothelial cell proliferation inhibitors (growth factors and their receptors), vascular targeted
agents (micro vessel disrupting agents) and anti-hypoxic agents (VEGF expression is
increased in hypoxic conditions) [102]. Endothelial cell proliferation inhibitors mainly
include agents inhibiting VEGF. VEGF is known to induce angiogenic response in tumour
models [103, 104]. As previously described, VEGF interacts with most angiogenic factors.
VEGF is also demonstrated to be present throughout the tumour life cycle [105]. Therefore,
inhibition of VEGF as an anti-angiogenic therapy could prove effective in cancer treatment.
Anti-VEGF drugs
At present, 3 anti-VEGF drugs are used in the treatment of cancer: bevacizumab, sorafenib
and sunitinib. All 3 drugs have been approved by the U.S. Food and Drug Administration
(FDA) for the treatment of specific types of cancer. These drugs inhibit VEGF signalling
either by blocking the VEGF ligand or the VEGF receptor. Bevacizumab is a humanised
monoclonal antibody that selectively binds to VEGF and specifically blocks the VEGF ligand
and signal reception [106]. It was the first systemically used VEGF inhibitor approved by the
FDA. It is currently approved in combination with irinotecan, fluorouracil and leucovorin
(IFL) as first- or second-line treatment of metastatic carcinoma of the colon or rectum.
Sunitinib and sorafenib are orally administered, small molecule inhibitors of multiple
receptor tyrosine kinases used in the treatment of tumour progression. Sunitinib inhibits
VEGF receptors (VEGFR-1, 2, 3), platelet derived growth factor receptors (PDGFR-a and b),
stem cell factor receptor (KIT), Fms-like tyrosine kinase-3 (FLT3), colony stimulating factor
receptor Type 1, and glial cell-derived neurotrophic factor receptor. It is approved for
advanced renal cell carcinoma and gastrointestinal stromal tumours (GIST) [9]. Sorafenib
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inhibits VEGFR-2, VEGFR-3, PDGFR-b, RAF kinase, FLT3, KIT, p38 MAP kinase (p38alpha, MAPK14). It is approved for treatment in advanced renal cell carcinoma and is in
phase III clinical trials for hepatocellular carcinoma, metastatic melanoma, and non small cell
lung cancer [107].
There are several other anti-VEGF drugs which are currently under different clinical phases:
1. GW786034B (pazopanib), a tyrosine kinase inhibitor, targets VEGFR1, 2 and 3.
It is under phase III trial for renal cell cancer [108].
2. AZD2171, a tyrosine kinase inhibitor, targets VEGFR1, 2, 3, PDGFRβ and CKIT. It is under phase I trial in combination therapy with carboplatin and
paclitaxel for advanced non small cell lung cancer [109].
3. PTK787/ZK222584 (vatalanib), a tyrosine kinase inhibitor, targets VEGFR1, 2,
3, PDGFRβ and C-KIT [110]. It is under phase I trial in combination with
cetuximab for advanced solid tumours [111].
4. VEGF trap is a decoy receptor which targets VEGF-A and B [112]. It is under
phase I trial for advanced solid tumours [113].
5. ZD6474, a tyrosine kinase inhibitor, targets VEGFR2, EGFR, FGFR1 and RET
[114]. It is under phase I trial for nasopharyngeal carcinoma [115].
6. AMG-706, a tyrosine kinase inhibitor, targets VEGFR1, 2 and 3, PDGFR1 and
KIT, a cytokine receptor expressed in haematopoietic stem cells [116]. It is under
phase Ib trial in combination with carboplatin/paclitaxel and/or panitumumab
for advanced non-small cell lung cancer [117].
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7. AG013736, a tyrosine kinase inhibitor, targets VEGFR1, 2, 3 and PDGFR [118].
It is under phase I study in combination with bevacizumab plus chemotherapy
or chemotherapy alone in patients with metastatic colorectal cancer and other
solid tumours [119].
Effects of VEGF inhibition on cardiovascular homeostasis
Hypertension
Anti-VEGF drugs inhibit endothelial cell proliferation by targeting endothelial mitogens,
their receptors, endothelial integrins and matrix metalloproteinases. This process leads to an
impairment of endothelial function, which in turn negatively affects cardiovascular
homeostasis [120]. Hypertension is the most frequently observed and documented side effect
of VEGF blocking in clinical trials with an estimated incidence of 32% [121]. Anti-VEGF
drugs could also reduce NO synthesis. This might further contribute to the vasoconstriction,
which in turn leads to increased peripheral resistance and blood pressure.
VEGF expression levels depend on the type of hypertension. For example, VEGF
expression has been shown to be reduced during intrauterine hypertension [122]. By
contrast, a study comparing VEGF mRNA expression in hypoxia induced (HI) vs.
carcinogen induced (CI) pulmonary hypertension showed increased VEGF levels in the
former and decreased VEGF levels in the latter [123]. VEGF expression is increased in
venous hypertensive conditions [124]. VEGF might convert venous hypertension into
intracellular signals for angiogenic activity [125]. Studies by Swendsen et al showed
higher sVEGFR1 concentrations in arteries vs. veins in rectal cancer patients [126]. The
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anti-VEGF drugs currently used might be specific for the arterial system. This
hypothesis warrants further studies where VEGF expression levels, signalling and
structural morphology in arteries and veins are studied simultaneously.
The incidence of arterial hypertension in clinical trials with anti-VEGF drugs ranges
between 0.2% and 72% (Error! Reference source not found.). Grade 3/4 hypertension (>
180/110 mmHg) was reported in most studies with a wide range of follow-up during
treatment (1-33 months) (Table 4: Clinical trials on anti-VEGF drugs and
development/worsening of hypertension Table 4).
Notably, the development of hypertension was more frequently observed with certain antiVEGF drugs such as sunitinib (5-56%), sorafenib (1-34%), AZD2171 (22-72%), AMG-706
(20-49%) and AG-013736 (6-61%), all of which inhibit PDGFR, than with others
(bevacizumab: 0.2-34%, ZD6474: 0.2-12%) (Table 4). PDGFR signalling helps in
recruitment of de novo VEGF from stromal fibroblasts in VEGF–null cells [127]. Therefore,
it is not surprising that PDGFR inhibition leads to an increased disturbance of vascular
homeostasis, which might explain at least partly the increased incidence of hypertension
with specific anti-VEGF drugs (Table 4).
Some studies have shown that the addition of platinum containing compounds to
bevacizumab treatment was associated with a lower incidence of hypertension (4.0% vs.
6.8%) [128, 129]. Platinum containing compounds act through activation of the MAPK
pathway which regulates cell proliferation, differentiation, survival and apoptosis [130].
Cisplatin activates the MAPK members, ERK (extracellular signal regulated kinase) and
SAPK (stress activated protein kinase, p38 kinase), following its exposure to tumour cells
[131]. This might explain the decreased incidence of hypertension when platinum containing
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compounds are co-administered with bevacizumab [132]. However, further studies are
required to confirm these findings.
Infused 5-fluorouracil with bevacizumab was associated with a reduced incidence of
hypertension (5%) compared with bolus dosing (22.4%) [121, 133]. Drugs administered by
intravenous bolus are rapidly cleared from the circulation, hence a relatively short plasma
half-life, whereas infusional dosing provides a sustained drug release [134]. Since there is a
sustained release, the total drug intensity and cumulative dose will be higher in infusional
administration compared with bolus administration. 5-fluorouracil has been shown to damage
endothelial cells and lead to thrombus formation [135]. Following the 5-fluorouracil induced
endothelial injury there is an increased release and leakage of vasodilatory and anti-coagulant
substances [136]. Only when this mechanism gets exhausted, pro-coagulant factors facilitate
thrombus formation [136]. In the above studies the incidence of thrombotic events was 19.4%
with bolus administration [121] vs. 18% with infusional dosing [133]. Considering the higher
cumulative dose and the similar incidence of thrombotic events it could be speculated that
when 5-fluorouracil is infused the release of vasodilatory and anti-coagulant substances is not
exhausted rapidly. This might explain the reduced incidence of hypertension with infusional
dosing of 5-flourouracil.
The clinical studies on bevacizumab have demonstrated a relatively low incidence of
hypertension in specific types of cancer. For example, studies on lung cancer showed a 6.8%
[128], 16.6% [132], 17.7%[137] and 16.1% [138] incidence of hypertension whereas studies
on gastric cancer showed a 4% [129] incidence of hypertension. Anti-VEGF drugs
specifically target VEGF which is an endothelial cell specific protein [139]. The lung
[140] and gastric [141] tissues are primarily lined with epithelial cells. Therefore, these
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tissues would have a reduced amount of VEGF proteins compared to those primarily
lined with endothelial cells, hence the reduced susceptibility to pro-hypertensive effects.
The development of hypertension regardless of tissue type could be secondary to
circulating endothelial cells (CEC), an increased levels of which have been documented
in different types of cancer [142]. CEC expression levels might be related with antiVEGF drug-induced hypertension as there is 1) a significant correlation between CEC
and plasma VEGF levels [143] and 2) an increased CEC expression in cancer [143].
[144]. CEC levels and kinetics might help in stratifying the clinical benefit provided by
anti-angiogenic treatment [145]. [146]. Gene expression profiling showed varied CEC
levels in different types of cancer [147]. Therefore, it could be hypothesised that the
extent of anti-VEGF drug-induced hypertension depends also on VEGF inhibition in
CEC.
Genetic factors might play an important role in the inter-individual differences in the risk of
developing hypertension during anti-VEGF treatment as well as in treatment efficacy. A
recent study has demonstrated that a particular VEGF genotype is associated with an
increased incidence of hypertension in patients with metastatic renal cell carcinoma
undertaking anti-VEGF treatment [148]. A phase III study demonstrated an association
between hypertension and certain VEGF genotypes [149]. VEGF has a number of
isoforms namely VEGF121 [20], VEGF145 [150], VEGF165 [103], VEGF183 [151], VEGF189
[152], and VEGF206 [153] which are formed by exon splicing at different regions. Further
studies on each of the isoforms are warranted to clarify the association between VEGF
polymorphism and risk of hypertension with anti-VEGF drugs.
There is evidence that bevacizumab-induced hypertension is associated with better
tumour response. For example, Scartozzi et al demonstrated that patients with colorectal
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cancer developing hypertension with bevacizumab had an increased progression free survival
(14.5 months) when compared with patients who did not develop hypertension (3.1 months)
[154]. Therefore, the development of hypertension could be used as marker of anti-VEGF
drug efficacy [146].
Due to the recent introduction of anti-VEGF drugs in clinical practice and the relatively
short survival of patients receiving them it is not possible to establish the long-term
impact of newly developed or worsened hypertension on cardiovascular outcomes.
Moreover, due to short half life of anti-VEGF drugs, their toxicities can be reverted to a
certain extent with the termination of treatment [155]. This hypothesis is supported by
recent studies demonstrating the rapid disappearance of capillary rarefaction following
termination of VEGF inhibition [156]. The proposed molecular pathway in this context is
the following: anti-VEGF drugs inhibit the PI3/Akt/PKB pathway, which is activated by
VEGF/VEGFR2 binding [51], thereby decreasing the induction of anti-apoptotic proteins
[81]. This would result in decreased tumour cell survival. VEGF also induces cell
proliferation by activating membrane associated GTPase through the Ras/MAPK
pathway [157], which is inhibited by anti-VEGF drugs. On the other hand, angiotensinII also induces the MAPK pathway [158]. Studies by Kishi et al showed that Ras protein
levels and the Ras/MAPK/ERK½ pathway are both up regulated in hypertensive rats
[159]. In addition, G-protein coupled receptor (GPCR) and Focal Adhesion Kinase (FAK)
activate the Ras/MAPK pathway [160] through the Kinase Suppressor of Ras (KSR). The
KSR-induced Ras/MAPK activation is shown to: 1) inhibit the PKB pathway in ceramide
treated cells [161] which would further prevent anti-apoptotic protein induction, thereby
leading to increased cell death; 2) initiate the c-Raf-1/MEK-1 pathway which
dephosphorylates BAD proteins [161]. The BAD protein is a pro-apoptotic member of the
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Bcl-2 family. Its apoptotic effects are enhanced by heterodimerisation with Bcl-xL [162] and
inhibited by its phosphorylation [163]; 3) activate endothelial angiotensin-II through NFκB
[164]. Ras activation of endothelial angiotensin-II contributes to the development of
angiotensin-II dependent hypertension [165] by up regulation of Elk-1 transcription factors
[166] (
Figure 4). The above studies suggest that the Ras/Raf/MAPK/ERK pathway is prohypertensive [157-160, 164, 165].
As discussed earlier, PDGF recruits de novo VEGF from stromal fibroblasts in VEGF–
null cells [127]. Currently used drugs targeting the Ras pathway inhibit VEGF as well
as PDGF [9, 107]. Anti-VEGF drugs would therefore inhibit the VEGF-induced Ras
pathway. This in turn would prevent PDGF-induced de novo VEGF which might
increase per se the incidence of hypertension. On the other hand, the Ras/MAPK
pathway is also initiated by other factors such as GPCR, FAK and angiotensin-II which
causes hypertension. In addition, Ras acts as an intermediatory protein linking PDGF
receptor to FAK [167], which is involved in mechanical signalling of hypertension [168].
We propose that the Ras pathway is pro-hypertensive regardless of anti-VEGF
treatment (angiotensin-II initiation). However, this effect is augmented during antiVEGF treatment (inhibition of PDGF-induced de novo VEGF + angiotensin-II
initiation).
Proteinuria
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Another common untoward cardiovascular effect during anti-VEGF treatment is
proteinuria. The incidence of proteinuria with bevacizumab is 23-38% in patients with
colorectal cancer and up to 64% in patients with renal cell carcinoma [169]. The
development of proteinuria and hypertension often coexist in the same patient.
Proposed mechanisms responsible for the development of anti-VEGF induced
proteinuria include a) hypertension-mediated glomerular damage [90]; b) reduced
VEGF expression by podocytes which adversely affects renal function with loss of
endothelial fenestrations in glomerular capillaries, proliferation of glomerular
endothelial cells, and loss of podocyte function [170, 171]; and c) pathological changes in
glomerular architecture resembling those observed in eclampsia [172].
There is overwhelming evidence that proteinuria significantly increases cardiovascular
risk [173]. However, similarly to hypertension, the clinical impact of this complication
in cancer patients receiving treatment with anti-VEGF remains to be established.
Moreover, proteinuria occurring during anti-VEGF therapy is usually mild and
temporary as it usually resolves upon treatment discontinuation.
Thrombosis and haemorrhage
Thrombosis and haemorrhage are other less frequently reported adverse events. The
reported incidence of thrombotic events during bevacizumab treatment plus
chemotherapy was 4% vs. 2% with chemotherapy alone [174]. Mild haemorrhagic
events during treatment with sunitinib occurred in 26% of patients whereas more
severe bleeding events occurred in 9% of patients [128].
22
As previously discussed, VEGF induces the synthesis of anti-apoptotic proteins [81].
Therefore, anti-VEGF drugs could trigger a pro-apoptotic state with consequent
endothelial cell injury [175]. This would expose extracellular matrix (ECM), collagen,
and von Willebrand factor (vWF) to circulating platelets, resulting in coagulation and
thrombus formation [176] (
Figure 5). ADAMTS, a metalloproteinase induced by VEGF, cleaves vWF [177, 178].
Therefore, anti-VEGF drugs might lead to increased vWF expression, thus escalating
thrombus formation. Other putative mechanisms to explain the increased risk of
thrombosis include reduced synthesis of NO and prostacyclin and increased blood
haematocrit and blood viscosity secondary to overproduction of the hormone
erythropoietin [179].
On the other hand, VEGF also induces tissue factor (TF) [180], an initiator of blood
coagulation [181]. Again, we could extrapolate that anti-VEGF drugs inhibit TF thereby
exerting anti-coagulant effects leading to haemorrhage. The lack of the previously
discussed effects of VEGF on vascular and endothelial cell integrity might also
contribute to the increased risk of haemorrhage.
The increased incidence of thrombosis and bleeding during anti-VEGF treatment
highlights once again the multiplicity of actions of VEGF on the vasculature.
Cardiac dysfunction
23
The untoward cardiac effects of anti-VEGF drugs primarily include heart failure with
left ventricular dysfunction, QT prolongation, and myocardial injury [182-185]. The
incidence of cardiac dysfunction ranges between 2-7% in patients treated with
trastuzumab [186], 2.2-3% with bevacizumab [187, 188], and 4-11% with sunitinib
[185]. The available evidence suggests that the increase in blood pressure secondary to
anti-VEGF treatment results in increased cardiac afterload, reduction of capillary
density in the myocardium, global contractile dysfunction and heart failure [189, 190].
Assessing the incidence of new-onset hypertension with anti-VEGF drugs methodological issues
The results of oncology studies assessing the incidence of newly-developed hypertension
during anti-VEGF treatment must be interpreted with caution for several reasons.
First, the rapid temporal changes in blood pressure could not be clearly established due
to the relative long time interval between assessment visits in most oncology trials [191].
A cohort study by Azizi et al showed an early and progressive blood pressure elevation
in 100% of patients undergoing weekly self-measurements at home [192]. Second,
several patients treated with anti-VEGF drugs had a previous nephrectomy. This
increases per se the risk of developing hypertension for several reasons, including
hypervolaemia [192] [193]. Therefore, the development of hypertension in such patients
should be analysed separately.
A third issue is related to the discrepancies in the definition of hypertension between
different professional societies. This might lead to inappropriate conclusions. For
example, a rise in blood pressure by 10 mmHg from any initial range is considered as
24
hypertension according to the ESH (European Society of Hypertension) definition.
However, it is considered as Grade 0 toxicity according to the NCI-CTC (National
Cancer Institute – Common toxicity criteria) definition if the increase is still within the
specified normal range [191]. Since hypertension is considered as a surrogate marker of
anti-VEGF treatment efficacy [146] considering blood pressure as a continuous, rather
than dichotomous, variable would help to overcome some of these methodological
concerns [191]. Clearly, more research is warranted.
Further putative mechanisms of anti-VEGF drug-induced hypertension
As previously discussed, VEGF exerts significant vasodilatory effects [78, 194]. The direct
inhibition of VEGF action should cause vasoconstriction resulting in increased blood
pressure. Interestingly, however, only a proportion of anti-VEGF drug treated patients
develop hypertension. Moreover, in those patients developing hypertension a significant
inter-individual variability in hypertension severity is observed. Whilst existing comorbidities and the co-administration of other cancer drugs might affect the risk of
developing hypertension, as discussed before, other pathways involved in vascular
homeostasis and blood pressure control might interact with the effects of VEGF and its
blockade. The role of these pathways is herewith discussed.
Haemodynamics
The anti-VEGF drug-mediated impairment in endothelial function would favour peripheral
arterial vasoconstriction, hence an increase in peripheral vascular resistance [106]. The
effects of an increase in peripheral vascular resistance on systemic blood pressure are
25
dependent on the elastic properties of the arterial wall, e.g. arterial compliance [195, 196].
There is good evidence that endothelial function tonically modulates arterial compliance as
impaired endothelial function significantly reduces arterial compliance, through NOdependent mechanisms [197]. A reduced arterial compliance, also described as increased
arterial stiffness, reduces the ‘buffering’ capacity of the arterial tree, in particular the large
arteries, during systole. This leads to a progressive increase in systolic blood pressure without
significant changes, or sometimes a reduction, in diastolic blood pressure [195] (Figure 6).
The susceptibility of an individual patient to anti-VEGF drug induced hypertension might
depend on a number of factors affecting arterial compliance. These include genetic
predisposition, co-existing cardiovascular risk factors and concomitant treatment with several
vasoactive drugs [198-200]. Since VEGF regulates vascular tone, anti-VEGF drugs could
affect vascular tone to cause changes in arterial compliance which in turn directly
affects large arteries, small arteries and arterioles [201]. Microvascular rarefaction is
one of the vascular dysfunctions associated with hypertension [202]. Steeghs et al in
2008 demonstrated that telatinib, an anti-VEGF drug during its phase I trial showed
significant reduction in capillary density and skin blood flux which could be due to an
increased rarefaction concurrent with the development of hypertension [203].
Baroreceptors
Baroreceptors are sensory mechano-receptors present in blood vessels [204]. They are located
in the following sites: 1) aortic arch at the origins of the brachiocephalic artery, the left
subclavian artery, and the Botallo’s duct; 2) brachiocephalic artery at its bifurcation into the
right subclavian and the right common carotid artery; 3) carotid sinuses; 4) carotid arteries at
the origin of the superior thyroid artery [205-207]. These receptors are sensitive to changes in
blood pressure and act by initiating or inhibiting the vasomotor centres located in the
26
brainstem in order to maintain blood pressure values within a physiological range [205]. They
send neuronal messages to the rostral ventrolateral medulla (RVLM) during alterations in
blood pressure which is reflected back by exerting modulatory effects on both the
parasympathetic and the sympathetic nervous system [208]. Anti-VEGF drugs could impair
baroreceptor function by preventing their sensitivity to blood pressure changes (
Figure 7). This might be secondary to the impairment of endothelial function caused by such
drugs, which would in turn lead to carotid artery stiffening and reduced baroreceptor
sensitivity [209]. Although anti-VEGF drug induced baroreceptor impairment could also be a
potential mechanism causing hypertension the factors affecting arterial compliance described
above could again account for inter-individual differences in both the development and the
severity of hypertension.
Cellular factors
VEGFR2 signalling is predominantly responsible for the angiogenic activity of VEGF. As
previously discussed, the binding of VEGF to VEGFR2 triggers the PI3-AKT pathway [51].
The key downstream function of PI3K activation is phosphorylation and regulation of its
targets such as GSK3 (Glycogen Synthase Kinase 3), IRS-1 (insulin receptor susbtrate-1),
PDE-3B (phosphodiesterase-3B), BAD protein, human caspase 9, Forkhead and NF-kB
transcription factors, mTOR, eNOS, Raf protein kinase, BRCA1 and p21Cip1 /WAF1 [210215]. The inhibition of the PI3-AKT pathway leads to decreased iNOS and cGMP
production [216] which is ought to occur during anti-VEGF treatment. Decreased cGMP
production is due to decreased availability of guanylate cyclase, the enzyme converting GTP
to cGMP [67]. eNOS is activated through AKT phosphorylation [217]. Therefore, AKT
27
inhibition by anti-VEGF treatment could also decrease eNOS expression and activity.
Moreover, cGMP is a gate for sodium ions [218]. The decreased production of cGMP would
lead to a reduced number of available sodium gates in endothelial cells. Retention of sodium
ions in the blood stream would lead to hypertonicity with increased blood volume and
increased blood pressure.
For similar reasons, patients undertaking chemotherapy drugs also targeting sodium channels
would possibly have an increased incidence of hypertension when co-administered with antiVEGF drugs. Other examples of drugs acting on sodium channels are listed below:
1. Alkaloids [219-221]
2. Local Anaesthetics [222]
3. Class I anti-arrhythmic agents [223]
4. Anticonvulsants [224]
Glomerular endothelial cells require VEGF expression to maintain their normal physiological
structure and function under both normotensive and hypertensive states [90]. This is inhibited
by anti-VEGF drugs, thereby causing an alteration in blood pressure. The co-factors
tetrahydrobiopterin [225] and calmodulin [226] modulate eNOS activity by facilitating NOS
dimer formation leading to NO synthesis and further blood pressure control. Drugs affecting
these factors could also alter blood pressure control [227-230].
Conclusions
VEGF exerts important effects on vascular homeostasis. A number of cancer drugs have been
recently developed that inhibit VEGF effects. Vasoconstriction and hypertension represent
28
common cardiovascular complications of anti-VEGF treatment in clinical trials. Other
important untoward effects include proteinuria, thrombosis and haemorrhage, and
cardiac dysfunction. This review has focussed on the physiological effects of VEGF as well
as the pathophysiology of hypertension in clinical trials with anti-VEGF drugs and sought to
provide some mechanistic insights into its inter-individual variability. Further research is
required to better identify genetic factors predisposing to these complications in order to
enhance risk stratification. Molecular and clinical studies focussing on the PI3-AKT pathway,
RAS pathway, iNOS, eNOS, cGMP, prostacyclin, sodium channel permeation, arterial
stiffness, baroreflex sensitivity and VEGF polymorphisms would help to address this
important issue.
29
Table 1: Angiogenic Factors
Angiogenic factors
Functions
Maturation of newly formed vessels
Suppression of vascular leakage
Angiopoietin-1
Inhibition of inflammation
Promotion of structural integrity of adult vasculature and
prevention of endothelial cell death
Angiopoitein-2
Angiopoietin-1 antagonist
Balances vascular regression and cell maturation
Placenta derived growth factor (PDGF-
Promotes neo-angiogenesis through PDGF-B/PDGFR-β
B) and receptor beta (PDGFR-β)
signalling
Fibroblast growth factor
Vascular endothelial growth factor
(VEGF)
VEGF receptor, neuropilin-1 and 2 coreceptors
Matrix metalloproteinase
Stimulation of proliferation and differentiation
Induces PDGFR-β
Modulation of vascular permeability
Induction of signal transduction
Sprouting of capillaries
Conversion of plasminogen to plasmin with fibrinolysis
Plasminogen activator
Promotion of remodelling processes such as proteolysis in
extracellular matrix aiding angiogenesis
Maintenance of a scaffold required for endothelial cell
Plasminogen activator inhibitor
migration by protecting the cell membrane from plasminmediated proteolysis
Delta notch
Ephrin EphB4
Cadherin, integrin
Development of endothelial cells on matrigel
Sprouting of functional blood vessels
Arterio-venous differentiation
Cell adhesion
Fibrin- or collagen-induced capillary formation
Netrin, Semaphorin
Axon guidance for neuron proliferation
Delta-like ligand 4 (DII4)
Negative feedback regulator of angiogenic sprouting
30
Table 2: VEGF activating factors
VEGF inducing
factors
Mechanism of induction
Physiological/pathological context
Cytokines
(interleukins and
other growth factors)
Cytokines are induced by hypoxic
conditions through NF kB
pathway by VEGF/VEGFR2
binding [53].
The promoter region of IL-6 contains the NF kB
binding site. This initiates the
physiological/pathological functions of
cytokines in hypoxic conditions to induce the
release of interleukin hormones and other
growth factors [54].
Hypoxia Inducing
Factor-alpha
HIF expression is activated
through the PI3–AKT–mTOR
pathway by VEGF/VEGFR2
binding
Normoxia promotes hydroxylation of HIF1alpha at proline residue to proteolyse it by the
VHL gene [231]. Decrease in oxygen stabilises
HIF protein which then initiates its own
physiological function. HIF1-β and CBP/p300
bind with hypoxia response element (HRE) to
increase the transcriptional activity of growth
factors, which is responsible for increase in
VEGF mRNA expression during low oxygen
tension [52].
Angiotensin II
Angiotensin regulates VEGF
expression through RAS (renin
angiotensin system) induced NFκB pathway in stromal fibroblasts
[57] by VEGF/VEGFR2 binding.
Angiotensin II regulation of VEGF expression
results in the formation of collagen in the
extracellular matrix which in turn is the
substrate for the formation of endothelial cells.
The VEGF promoter region contains the
binding site for AP-1 and NF-κB [152].
Matrix
metalloproteinase
Activated by Src tyrosine kinase
activity [48].
Specific transcriptional up regulation of
VEGF-A in tumour angiogenesis [47].
NF-κB pathway
Activated by
VEGF/VEGFR2/p38MAPKMKK2 signalling [232].
NF-kappa B promotes the expression of VEGF
and iNOS [55].
Endothelin-1
Endothelin-1 upregulates VEGF
expression which is associated
with the induction of HIF-1β and
HIF-2α [233].
Endothelin and VEGF maintain the normal
functioning of vascular tone [56].
31
Table 3: VEGF activated factors
VEGF induced factors
Mechanism of action
Physiological/Pathological context
Endothelial nitric oxide
synthase (eNOS) and
inducible nitric oxide
synthase (iNOS)
Activated by VEGF/VEGFR2
binding through PI3-AKT
pathway [59].
NOS catalyses the formation of NO in
endothelial cells to maintain vascular
haemostasis.
Vascular cellular adhesion
molecule (VCAM),
intercellular adhesion
molecule (ICAM) and Eselectin
Activated via Nuclear Factor-κB
activation by VEGF/VEGFR2
binding specifically dependent
upon PI3 kinase [60].
Adhesion factors involved during
endothelial cell proliferation.
Tissue type plasminogen
activator (PA), plasminogen
activator inhibitor (PAI) and
collagenase [58]
Activated via ERK1/2 pathway
by VEGF/VEGFR1 binding
[234].
Formation of fibrin gel in the
extravascular region which is a substrate
for the formation of new blood vessels on
the endothelial cell layer. VEGF balances
the extracellular proteolysis during
endothelial cell morphogenesis. This
facilitates the migration and sprouting of
blood vessels in endothelial cells [5].
Urokinase-type plasminogen
activator (uPA) and its
receptor (uPAR) [235]
Activated via protein kinase C
dependent pathway [236]
Important cell signalling process during
cell invasion and cellular remodelling,
affecting vascular morphogenesis [237].
Focal adhesion kinase
Activated by VEGF-VEGFR2
binding [61].
Enhances cellular migration via HSP90
[61, 62].
Hexose transport and tissue
factor (TF) [238]
Hexose transport is performed
by VEGF-VEGFR2 activation
of PKC-β which mediates the
translocation of cytosolic
GLUT-1 to plasma membrane
surface [239].
TF activation by VEGF is
mediated by EGR-1, a
transcription factor [180].
Both factors are activated by
VEGF/VEGFR2 binding
A disintegrin and
metalloproteinase with
thrombospondin motifs
(ADAMTS)
Activated via protein kinase
dependent pathway [178].
During mitosis and inflammation, cells
require increased glucose metabolism to
transform their nonthrombogenic surface
to a procoagulant surface. This
transformation is performed by a tissue
factor (TF) which is induced by VEGF
and TNF [240] as a result of a cellular
response in order to maintain vascular
haemostasis during cell proliferation
[238].
Angiogenesis inhibitor which acts as a
regulator of endothelial cell proliferation
during vascular morphogenesis to
maintain vascular haemostasis [178].
32
Table 4: Clinical trials on anti-VEGF drugs and development/worsening of hypertension
Ref.
Study information
Name and dose of antiVEGF drug
Additional
drug(s)
Cancer type
Age
(years)
No. of
pts
Duration of
the study
(months)
Development of hypertension
[241]
Phase I/II dose
escalation trial
Bevacizumab - escalating
doses ranging from 3
mg/kg to 20 mg/kg
-
Metastatic breast
cancer
29-78
75
5
Hypertension: 22%
[242]
Phase II study
Bevacizumab 10 mg/kg
Docetaxel
Metastatic Breast
cancer
39-68
27
1-15
(median 6)
Grade 2 hypertension: 15%, grade 3
hypertension: 4%
[243]
Randomized, doubleblind, phase II trial
Bevacizumab - 3 and 10
mg/kg
-
Metastatic renal
cancer
53.5
(median)
76
27
Hypertension: 1 pt (3mg/kg), 14 pts (10
mg/kg)
[128]
Randomized phase II
study
Bevacizumab - 7.5 and 15
mg/kg
Paclitaxel,
Carboplatin
Non-small cell lung
cancer
≥65
417
33
Grade 3 hypertension: 6.8%, grade 4
hypertension: 0.2%
[132]
Randomized phase II
trial
Bevacizumab - 7.5 and 15
mg/kg
Paclitaxel,
Carboplatin
Metastatic nonsmall cell lung
cancer
≥18
67
3
All grades hypertension: 16.6%
[129]
Phase II study
Bevacizumab - 7.5 mg/kg
Docetaxel,
Oxaliplatin
Gastric and
gastroesphageal
junction cancer
57
(median)
23
-
Grade 3/4 hypertension: 4%
[244]
Randomized phase II
trial
Bevacizumab - 5 mg/kg
and 10 mg/kg
Fluorouracil
Leucovorin
Metastatic
colorectal cancer
≥18
68
12
All grades hypertension: 11% (5mg), 28%
(10 mg); Grade 3/4 hypertension: 3%
(5mg), 8% (10mg)
[137]
Multicenter,
randomized phase II
trial
Bevacizumab - 15 mg/kg
Erlotinib,
(Docetaxel or
pemetrexed)
Non small cell lung
cancer
40-88
79
13
All grades hypertension: 17.7%
33
[187]
Open label,
randomized phase III
clinical trial
Bevacizumab - 10mg/kg
Paclitaxel
Metastatic breast
cancer
29-84
365
26
Grade 3 hypertension: 14.5%, grade 4
hypertension: 0.3%
[188]
Randomized phase III
trial
Bevacizumab - 15 mg/kg
Capecitabine
Metastatic breast
cancer
29-78
232
26
All grades hypertension: 17.9%
[245]
Randomized phase III
trial
Bevacizumab - 7.5 mg/kg
Capecitabine,
Oxaliplatin
Cetuximab
Advanced colorectal
cancer
31-83
389
6.8
Grade 3/4 hypertension: 5%
[246]
Multicenter,
randomized, doubleblind, phase III trial
Bevacizumab - 10 mg/kg
Interferon-2
alpha
Metastatic renal cell
carcinoma
18-82
327
13.3
Hypertension: 3%
[247]
Randomized phase III
trial
Bevacizumab - 10 mg/kg
Oxaliplatin
Leucovorin
Fluorouracil
Metastatic
colorectal cancer
23-85
529
5
Grade 3 hypertension: 7.3%
[121]
Randomized phase III
trial
Bevacizumab - 5 mg/kg
Irinotecan
Leucovorin
Fluorouracil
Metastatic
colorectal cancer
59.5
(mean)
402
10
All grades hypertension: 22.4%, grade 3/4
hypertension: 11%
[248]
Randomized phase III
trial
Bevacizumab - 5 mg/kg
Fluorouracil
Leucovorin
59.7
(mean)
110
24
All grades hypertension: 33.9%, grade 3/4
hypertension: 18.3%
[133]
International,
multicenter, openlabel, phase IV trial
Bevacizumab - 5 mg/kg
Infusional
Fluorouracil,
Leucovorin
Irinotecan
Metastatic
colorectal cancer
31-82
150
9
Hypertension: 5%
[138]
Phase I study
Sorafenib - 200 and 400
mg
Gefitinib
Refractory or
recurrent non-small
cell lung cancer
46-78
31
1 - 12
(median 3)
All grades hypertension: 16.1%, grade 3
hypertension: 3.2%
[249]
Phase I study
Sorafenib - 400 mg
Erlotinib
Advanced solid
tumours
30-77
17
10
All grades hypertension: 34%
Metastatic
colorectal cancer
34
[250]
Phase I study
Sorafenib - 400 mg
Gemcitabine
Advanced solid
tumours
39-83
42
2-15
(median 4)
All grades hypertension: 7.1%
[251]
Open-label phase II
study
Sorafenib - 400 mg
-
Metastatic, iodinerefractory thyroid
carcinoma
31-89
36
5
Grade 3 hypertension: 8%
[252]
Open label, single
arm phase II study
Sorafenib - 400 mg
-
Androgen
independent
prostate cancer
50-77
22
1
Grade 1 hypertension: 4 pts, grade 2
hypertension: 3 pts, grade 3 hypertension:
1 pt
[253]
Phase II study
Sorafenib - 400 mg
-
Hormone refractory
prostate cancer
52-82
55
3
Grade 3 hypertension: 6%
[254]
Phase II study
Sorafenib - 400 mg
-
Advanced thyroid
cancer
31-89
30
7
Grade 1/2 hypertension: 30%, grade 3/4
hypertension: 13%
[255]
Phase II study
Sorafenib - 400 mg
-
Advanced renal cell
carcinoma
-
131
6
All grades Hypertension - 27.5%, Grade
3/4 hypertension - 12.2%
[256]
Phase II study
Sorafenib - 400 mg
-
Metastatic
castration resistant
prostate cancer
49-85
24
2-12
(median
2.5)
Grade 2 hypertension: 12.5%
[257]
Phase II study
Sorafenib - 400 mg
-
Advanced
hepatocellular
carcinoma
28-79
51
2.5-16
(median 3)
Grade 1/2 hypertension: 14%, grade 3
hypertension: 8%
[258]
Phase II study
Sorafenib - 400 mg
Interferon
alpha 2B
Metastatic renal cell
cancer
33-81
40
2-17
(median 6)
Grade 1/2 hypertension: 10%
[259]
Phase II study
Sorafenib – 400 mg and
Axitinib – 5 mg
-
Metastatic renal cell
carcinoma
-
62
17.5
All grades hypertension: 16.1%
[260]
Phase III study
Sorafenib - 400 mg
-
Advanced renal cell
carcinoma
-
451
4.5
Grade 3 hypertension: 3%
35
[261]
Phase I study
Sunitinib - 25, 37.5 and
50 mg
-
Metastatic renal cell
carcinoma
57
(median)
25
7.5
(median)
Grade 3/4 hypertension: 56%
Bevacizumab - 10 mg/kg
[262]
Phase II study
Sunitinib - 50 mg
-
Metastatic
colorectal cancer
30-78
82
2.5
All grades hypertension: 18.3%; grade 3/4
hypertension: 6.1%
[263]
Multicenter, Phase II
study
Sunitinib - 50 mg
-
Advanced nonsmall cell lung
cancer
33-86
63
13.5
All grades hypertension: 11%; grade 3
hypertension: 5%
[264]
Phase II, open-label,
multicenter study
Sunitinib - 50 mg
-
Metastatic breast
cancer
36-70
64
1-12
(median 3)
All grades hypertension: 16%; grade 3
hypertension: 6%
[265]
Phase II study
Sunitinib - 50 mg
-
Refractory thyroid
cancer
58
(median)
43
3
All grades hypertension: 42%; grade 3/4
hypertension: 16%
59
(median)
22
2.5
Grade 3/4 hypertension: 22.7%
[266]
Phase II study
Sunitinib - 50 mg
-
Recurrent and/or
metastatic
squamous cell
carcinoma of the
head and neck
[267]
Multicenter,
randomized, phase III
trial
Sunitinib - 50 mg
Interferon alfa
Metastatic renal cell
carcinoma
27-87
375
1-15
(median 6)
All grades hypertension: 24%; grade 3
hypertension: 8%
[268]
Phase I dose
escalation and
pharmacokinetic
study
AZD2171 - Escalating
doses 1, 2.5, 5, 10, 20, 30
mg
-
Hormone refractory
prostate cancer
50-90
26
-
All grades hypertension: 31%
[269]
Phase I study
AZD2171 - 20, 30 and 40
mg
-
Advanced solid
tumours
19-78
83
3
All grades hypertension: 29%
36
[270]
Phase II study
AZD2171 - 45 mg
-
Recurrent or
persistent ovarian,
peritoneal or
fallopian tube
cancer
31-87
1-9
(median 3)
All grades hypertension: 72%; grade 3
hypertension: 33%
4 week
cycle
All grades hypertension: 50%; grade 3
hypertension: 21.7%
49
[271]
Phase II study
AZD2171 - 45 mg
-
Advanced
metastatic renal cell
carcinoma
44-80
23
[272]
Phase I dose
escalation trial
VEGF trap (Aflibercept) 4 mg/kg (20 pts) and 6
mg/kg (12 pts)
Gemcitabine
Advanced solid
tumours
38-75
32
[273]
Double-blind,
placebo-controlled,
multi-center phase II
trial
VEGF trap (Aflibercept) 4 mg/kg
-
Metastatic ovarian
cancer
-
55
-
Grade 3/4 hypertension: 7%
[274]
Phase II trial
VEGF trap (Aflibercept) 4 mg/kg
-
Metastatic
colorectal cancer
39-80
51
3 (median)
All grades hypertension: 54.9%; grade 3
hypertension: 7.8%
[275]
Phase II trial
VEGF trap (Aflibercept) 4 mg/kg
-
Recurrent or
metastatic
gynaecologic soft
tissue sarcoma
-
25
2-28
(median 4)
Grade 3 hypertension: 18%
[276]
Phase I study
AG-013736 - 5 to 30 mg
-
Advanced solid
tumours
41-76
36
28 day cycle
All grades hypertension: 61%; grade 3
hypertension: 30%
[277]
Phase I study
AG-013736 - 5 mg
Gemcitabine
Advanced
pancreatic cancer
-
8
0.7-4.5
(median
2.2)
Grade 2 hypertension: 37.5%
-
Acute myeloid
leukemia or
myelodysplastic
syndrome
58-88
12
0.03-6
(median
2.7)
Grade 3/4 hypertension: 25%
[278]
Phase II study
AG-013736 - 5 mg
1-9
Grade 3 hypertension: 22%
(median 2)
37
[279]
Phase II study
AG-013736 - 5 mg
-
Advanced nonsmall cell lung
cancer
39-80
32
3
Grade 3/4 hypertension: 6%
[280]
Phase II study
AG-013736 - 5 mg
-
Advanced thyroid
cancer
26-84
60
0.2-12
All grades hypertension: 20%
[281]
Two centre, phase I,
open label, sequential
dose escalation study
AMG-706 - 50 to 175 mg
-
Advanced solid
tumours
25-90
71
1
All grades hypertension: 42%; grade 3
hypertension: 20%
[282]
Multicenter, open
label, phase II, single
arm study
AMG-706 - 125 mg
-
Differentiated
thyroid cancer
36-81
93
3.5
All grades hypertension: 49%; grade 3
hypertension: 22%
[283]
Phase I dose
escalation trial
ZD6474 - 50, 100, 200,
300, 500, 600mg
-
Solid malignant
tumour
28-82
77
2.5
Grade 3 hypertension: 2% vs. 0% vs. 1%
vs. 0% vs. 1% vs. 4%
[284]
Multicentre Phase II
trial
ZD6474 - 100 and 300
mg
-
Metastatic breast
cancer
32-81
46
1.5
Grade 1 hypertension in 300 mg group:
2.4%
[285]
Open label phase II
study
ZD6474 - 300mg
-
Hereditary
metastatic
medullary thyroid
cancer
22-77
16
0.5-12.5
(median
4.5)
Grade 3 hypertension: 12.5%
[286]
Open label, phase II
study
PTK787/ZK222584
(vatalanib) - 1250 mg
-
Metastatic
gastrointestinal
stromal tumour
42-77
15
0.9-24.8
(median
9.1)
Grade 1/2 hypertension: 13%
38
Tumour & Normal cells
VEGF-B
VEGFR1
PIGF
sVEGFR1
VEGF-A
Nrp-1
VEGF-E
VEGFR2
VEGF-D
VEGFR3
VEGF-C
Nrp-2
Endothelial
cell
membrane
Decoy effect on Co-receptor
VEGF
signaling: for VEGFR2
Induction of uPA,
tPA, MMP9;Vascular
bed specific release
of growth factors
Proliferation,
migration, survival
and angiogenesis in
vascular endothelial
cells
Proliferation,
Co-receptor
migration, survival for VEGFR3
and angiogenesis in
lymphatic
endothelial cells
Figure 1: VEGF and its receptors
uPA – Urokinase plasminogen activator; tPA – Tissue Plasminogen activator; MMP – Matrix
metalloproteinase; VEGF – Vascular endothelial growth factor; VEGFR – Vascular endothelial
growth factor receptor
39
Cellular
migration
and Invasion
Actin
reorganisation
PI3K
FAK/
Paxillin
VEGFR2
PLCγ
Binds to
VEGF
SHC
Ras-Raf
PKC
PKB
ADAMTS
ERK
AKT
Bcl-2
AntiApopto
sis
mTOR
Cell
proliferati
on,
vasoper
meability
S6K
Regulation
of EC
proliferatio
n by
negative
feedback
mechanis
m
IP3
RAS
P42/44MAPK
MEK½
Ca++
MKK2
PA & PAI
P38MAPK
Angiote
nsin-II
NOS
NO
Proliferation
& gene
expression
eIF4EI
Vasodilation
Through
AP-1
binding
site
NF-κB
ERK½
Growth,
differentiation
&
development
VCAM,
ICAM & ESelectin
HIF1-α
With
HIF1-β
ARNT
Binds
P300 &
CREB
COMPL
EX (HIF,
ARNT,
P300,CR
EB,JAB1
, CJUN
Binds
HRE
Activation
of
transcriptio
nal factors
Cell adhesion
CYTOKINES
Figure 2: VEGF/VEGFR2 signal transductions
VEGF and its signal transductions with VEGFR2 binding. PI3K – Phosphoinositol 3 kinase; PKB –
Protein kinase B; mTOR – Mammalian target of Rapamycin; S6K – S6 protein kinase; eIF4E1 Eukaryotic Translation Initiation Factor 4E1; HIF1 α – Hypoxia inducing factor 1α; HIF1 β –
Hypoxia inducing factor 1β; ARNT – Aryl hydrocarbon receptor nuclear translocator; P300 - ; CREB
– cAMP response element binding; JAB1 – Jun activation domain binding; cJUN – Cellular JUN;
HRE – Hypoxia response elements; NF-κB – Nuclear Factor Kappa B; NO – Nitric oxide; NOS –
Nitric oxide synthase; ERK – Extracellular signal regulated kinase; PLC – Phospholipase C; PKC –
Protein kinase C; ADAMTS – A disintegrin and metalloproteinase with thrombospondin motifs; IP3 –
Inositol triphosphate; SHC – Src homology 2 Domain containing; RAS – Renin Angiotensin system;
MKK2 – Mitogen activated protein kinase kinase 2; MAPK – Mitogen activated protein kinase; PA –
Plasminogen activator; PAI – Plasminogen activator inhibitor; MEK – MAPK/ERK kinase; VCAM –
Vascular cellular adhesion molecule; ICAM – Intercellular adhesion molecule.
40
VEGF
Binds
VEGF-VEGFR2
Binding
VEGFR1 Presents VEGF VEGFR2
Further signal
transductions
By deleting an allelic gene of VEGFR1:
VEGF
VEGFR1
Hypoxia
HIF-α
Induction
Release of
cytokines
VEGFR2
Hypertension
Oxidative
stress
Leakage of plasma
proteins & cellular
factors
Endothelial
dysfunction
Semaphorin
Induction
Proteinuria
Binds to Neuropilin-1
Sympathetic nerve
collapse
Accumulation
of VEGF
Accumulation
of VEGF
Increased VEGF
mRNA
Binds to Neuropilin-1
Reno protective
effect
Vascular
sympathetic
Innervation
Increased
VEGF mRNA
Increased Microvascular
permeability
No VEGFVEGFR2 Binding
Normal Physiology
of ANS
PA, PAI, TF, VCAM,
ICAM, E-Selectin
Balanced by
VEGF
Maintains
endothelial
cell Integrity
Figure 3: Maintenance of vascular homeostasis by VEGF
Normal Physiology
of Cardiovascular
system
Vascular
Homeostasis
maintenance
by VEGF
41
VEGF/VEGFR2
binding
Other factors (GPCR,
FAK, Angiotensin II)
Inhibits
Anti-VEGF
drugs
PI3-AKT
signalling
Inhibits
Activates
Inhibits
Ras
PKB
Induction
Increased Cell
survival
Activates
C-Raf/MEK1 pathway
Dephosphorylation of
BAD proteins
Increased Tumour
response to antiVEGF drugs
Akt
Antiapoptotic
proteins
Induction
KSR
Inhibits
Ras/Raf/p38
MAPK/ERK
pathway
Angiotensin
II production
Elk-1
transcription
factor
activation
Increased Tumour
cell apoptosis
Vasoconstriction
Hypertension
Figure 4: Anti-VEGF induced hypertension with increased tumour response
42
Figure 5: Anti-VEGF drugs and thrombosis
43
Anti-VEGF
drug
Impairment of
Endothelial
function
Peripheral Arterial
Vasoconstriction
Increased peripheral
vascular resistance
Nitric oxide down
production
Decrease in Arterial
compliance
Increase in Arterial
stiffness
Reduced buffering capacity of
large arteries
Figure 6: Cardiovascular effects of anti-VEGF drugs
Increased SBP and no
significant change in DBP
44
Anti-VEGF
drugs
Impaired
sensitivity to
altered BP
Baroreceptor
Sensitivity
Send neuronal
messages to RVLM
During
Increased BP
During
decreased BP
Inhibit
Vasomotor centre
Initiate Vasomotor
centre
Decrease HR and
CO
Increase HR &
CO
Normal BP
Figure 7: Effect of anti-VEGF drug on baroreceptor function
Does not send
neuronal messages to
RVLM
Hypertension
45
References
[1].
Ferrara N, Henzel W. Pituitary follicular cells secrete a novel heparin-binding growthfactor specific for vascular endothelial-cells. Biochemical and biophysical research
communications. 1989;161(2):851-8.
[2].
Hamilton WJ, Boyd JD, Mossman HW. Human Embryology. Academic Medicine.
1963;38(9):779.
[3].
Risau W. Differentiation of endothelium. FASEB J. 1995;9(10):926-33.
[4].
Ferrara N, CarverMoore K, Chen H, Dowd M, Lu L, OShea K, et al. Heterozygous
embryonic lethality induced by targeted inactivation of the VEGF gene. Nature.
1996;380(6573):439-42.
[5].
Ferrara N, DavisSmyth T. The biology of vascular endothelial growth factor.
Endocrine reviews. 1997;18(1):4-25.
[6].
Gerber HP, Hillan KJ, Ryan AM, Kowalski J, Keller GA, Rangell L, et al. VEGF is
required for growth and survival in neonatal mice. Development. 1999;126(6):1149-59.
[7].
Maharaj ASR, D'Amore PA. Roles for VEGF in the adult. Microvascular Research.
2007;74(2-3):100-13.
[8].
Folkman J, In DeVita VJ, Hellman S, Rosenberg S. Cancer: Principles and Practice of
Oncology. Philadelphia: Lippincott Williams & Wilkins; 2005.
[9].
Jain R, Duda D, Clark J, Loeffler J. Lessons from phase III clinical trials on antiVEGF therapy for cancer. Nature Clinical Practice Oncology. 2006;3(1):24-40.
[10]. Bergers G, Brekken R, McMahon G, Vu TH, Itoh T, Tamaki K, et al. Matrix
metalloproteinase-9 triggers the angiogenic switch during carcinogenesis. Nat Cell Biol.
2000;2(10):737-44.
[11]. Gerber H, Ferrara N. The role of VEGF in normal and neoplastic hematopoiesis.
Journal of Molecular Medicine. 2003;81(1):20-31.
[12]. Johnstone S, Logan RM. Expression of vascular endothelial growth factor (VEGF) in
normal oral mucosa, oral dysplasia and oral squamous cell carcinoma. International Journal
of Oral and Maxillofacial Surgery. 2007;36(3):263-6.
[13]. Shweiki D, Itin A, Soffer D, Keshet E. Vascular endothelial growth factor induced by
hypoxia may mediate hypoxia-initiated angiogenesis. Nature. 1992;359:843-5.
[14]. Plate K, Breier G, Weich H, Risau W. Vascular endothelial growth factor is a potential
tumour angiogenesis factor in human gliomas in vivo. Nature. 1992;359:845-8.
[15]. Bałan B, Słotwińsk R. VEGF and tumour angiogenesis. Centr Eur J Immunol.
2008;33(4):232-6.
[16]. Shibuya M. Vascular endothelial growth factor-dependent and -independent
regulation of angiogenesis. BMB reports. 2008;41(4):278-86.
[17]. Lyttle DJ, Fraser KM, Fleming SB, Mercer AA, Robinson AJ. Homologs of vascular
endothelial growth factor are encoded by the poxvirus orf virus. J Virol. 1994;68(1):84-92.
[18]. Shibuya M, Claesson-Welsh L. Signal transduction by VEGF receptors in regulation
of angiogenesis and lymphangiogenesis. Experimental Cell Research. 2006;312(5):549-60.
[19]. Vincenti V, Cassano C, Rocchi M, Persico G. Assignment of the vascular endothelial
growth factor gene to human chromosome 6p21.3. Circulation. 1996;93:1493-5.
[20]. Houck A, Ferrara N, Winer J, Cachianes G, Li B, Leung D. The vascular endothelial
growth factor family: Identification of a fourth molecular species and characterization of
alternative splicing of RNA. Mol endocrinol. 1991;5:1806-14.
46
[21]. Houck A, Leung D, Rowland A, Winer J, Ferrara N. Dual regulation of vascular
endothelial growth factor biavailability by genetic and proteolytic mechanisms. J Biol Chem.
1992;267:26031-7.
[22]. Alitalo K, Carmeliet P. Molecular mechanisms of lymphangiogenesis in health and
disease. Cancer cell. 2002;1(3):219-27.
[23]. Morishita K, Johnson D, Williams L. A novel promoter for vascular endothelial
growth factor receptor (flt-1) that confers endothelial specific gene expression. J Biol Chem.
1995;270:27948-53.
[24]. Patterson C, Perrella M, Hsieh C, Yoshizumi M, Lee M, Haber E. Cloning and
functional analysis of the promoter for KDR/flk-1, a receptor for vascular endothelial growth
factor. J Biol Chem. 1995;270:23111-8.
[25]. Ferrara N. VEGF and the quest for tumour angiogenesis factors. Nat Rev Cancer.
2002;2:795-803.
[26]. Davis-smyth T CH, Park J, Presta LG, Ferrara N. . The second immunoglobulin like
domain of the tyrosine kinase receptor Flt-1 determines ligand binding and may initiate signal
transduction cascade. Embo J. 1996;15:4919-27.
[27]. Brekken R, Overholser J, Stastny V, Waltenberger J, Minna J, Thorpe P. Selective
inhibition of vascular endothelial growth factor (VEGF) receptor 2 (KDR/Flk-1) activity by a
monoclonal anti-VEGF antibody blocks tumor growth in mice. Cancer research.
2000;60(18):5117-24.
[28]. Barleon B, Totzke F, Herzog C, Blanke S, Kremmer E, Siemeister G, et al. Mapping
of the sites for ligand binding and receptor dimerization at the extracellular domain of the
vascular endothelial growth factor receptor FLT-1. J Biol Chem. 1997;272:10382-8.
[29]. Soker S, Takashima S, Miao H, Neufeld G, Klagsbrun M. Neuropilin-1 is expressed
by endothelial and tumor cells as an isoform-specific receptor for vascular endothelial growth
factor. Cell. 1998;92(6):735-45.
[30]. Gluzman-Poltorak Z, Cohen T, Herzog Y, Neufeld G. Neuropilin-2 and neuropilin-1
are receptors for the 165-amino acid form of vascular endothelial growth factor (VEGF) and
of placenta growth factor-2, but only neuropilin-2 functions as a receptor for the 145-amino
acid form of VEGF. The Journal of biological chemistry. 2000;275(24):18040-5.
[31]. Autiero M, Waltenberger J, Communi D, Kranz A, Moons L, Lambrechts D, et al.
Role of PlGF in the intra- and intermolecular cross talk between the VEGF receptors Flt1 and
Flk1. Nat Med. 2003;9:936-43.
[32]. Berndt JD, Halloran MC. Semaphorin 3d promotes cell proliferation and neural crest
cell development downstream of TCF in the zebrafish hindbrain. Development.
2006;133(20):3983-92.
[33]. Kendall R, Wang G, Thomas K. Identification of a natural soluble form of the
vascular endothelial growth factor receptor, FLT-1, and its heterodimerization with KDR.
Biochem Biophys Res commun. 1996;226:324-8.
[34]. Ye C, Feng C, Wang S, Wang K, Huang N, Liu X, et al. sFlt-1 gene therapy of
follicular thyroid carcinoma. Endocrinology. 2004;145:817-22.
[35]. Mahasreshti P, Navarro J, Kataram M, Wang M, Carey D, Siegal G, et al.
Adenovirus-mediated soluble FLT-1 gene therapy for ovarian carcinoma. Clin Cancer Res.
2001;7:2057-66.
[36]. Hasumi Y, Mizukami H, Urabe M, Kohno T, Takeuchi K, Kume A, et al. Soluble
FLT-1 expression suppresses carcinomatous ascites in nude mice bearing ovarian cancer
Cancer Research. 2002;62:2019-23.
47
[37]. Kendall R, Thomas K. Inhibition of vascular endothelial cell growth factor activity by
an endogenously encoded soluble receptor. Proc Natl Acad Sci 1993;90:10705-9.
[38]. Greenblatt M, Shubik P. Tumor Angiogenesis: Trans filter diffusion studies by the
transparent chamber technique. J Natl Cancer Inst. 1968;41:111-24.
[39]. Yancopoulos GD, Davis S, Gale NW, Rudge JS, Wiegand SJ, Holash J. Vascularspecific growth factors and blood vessel formation. Nature. 2000;407(6801):242-8.
[40]. Suri C, Jones PF, Patan S, Bartunkova S, Maisonpierre PC, Davis S, et al. Requisite
Role of Angiopoietin-1, a Ligand for the TIE2 Receptor, during Embryonic Angiogenesis.
1996;87(7):1171-80.
[41]. Maisonpierre PC, Suri C, Jones PF, Bartunkova S, Wiegand SJ, Radziejewski C, et al.
Angiopoietin-2, a Natural Antagonist for Tie2 That Disrupts in vivo Angiogenesis. Science.
1997;277(5322):55-60.
[42]. Thurston G. Complementary actions of VEGF and Angiopoietin-1 on blood vessel
growth and leakage. Journal of Anatomy. 2002;200(6):575-80.
[43]. Lobov IB, Brooks PC, Lang RA. Angiopoietin-2 displays VEGF-dependent
modulation of capillary structure and endothelial cell survival in vivo. Proceedings of the
National Academy of Sciences of the United States of America. 2002;99(17):11205-10.
[44]. Kano MR, Morishita Y, Iwata C, Iwasaka S, Watabe T, Ouchi Y, et al. VEGF-A and
FGF-2 synergistically promote neoangiogenesis through enhancement of endogenous
PDGFB-PDGFRβ signaling. J Cell Sci. 2005;118(16):3759-68.
[45]. Pepper MS, Ferrara N, Orci L, Montesano R. Potent synergism between vascular
endothelial growth factor and basic fibroblast growth factor in the induction of angiogenesis
in vitro. Biochemical and biophysical research communications. 1992;189(2):824-31.
[46]. Pan Q, Chathery Y, Wu Y, Rathore N, Tong RK, Peale F, et al. Neuropilin-1 Binds to
VEGF121 and Regulates Endothelial Cell Migration and Sprouting. Journal of Biological
Chemistry. 2007;282(33):24049-56.
[47]. Sounni N, Janssen M, Foidart J, Noel A. Membrane type-1 matrix metalloproteinase
and TIMP-2 in tumor angiogenesis. Matrix Biol. 2003;22(1):55-61.
[48]. Sounni NE, Roghi C, Chabottaux V, Janssen M, Munaut C, Maquoi E, et al. Upregulation of Vascular Endothelial Growth Factor-A by Active Membrane-type 1 Matrix
Metalloproteinase through Activation of Src-Tyrosine Kinases. Journal of Biological
Chemistry. 2004;279(14):13564-74.
[49]. Pepper M, Ferrara N, Orci L, Montesano R. Vascular endothelial growth factor
(VEGF) induces plasminogen activators and plasminogen activator inhibitor type 1 in
microvascular endothelial cells. Biochemical and biophysical research communications.
1991;181(2):902-6.
[50]. Lawson ND, Vogel AM, Weinstein BM. Sonic hedgehog and vascular endothelial
growth factor Act Upstream of the Notch Pathway during Arterial Endothelial
Differentiation. Developmental Cell. 2002;3(1):127-36.
[51]. Rini B, Small E. Biology and clinical development of vascular endothelial growth
factor-targeted therapy in renal cell carcinoma. J Clin Oncol. 2005;23:1028-43.
[52]. Wenger RH, Stiehl DP, Camenisch G. Integration of Oxygen Signaling at the
Consensus HRE. Sci STKE. 2005;2005(306):12.
[53]. Berse B, Hunt J, Diegel R, Morganelli P, Yeo K, Brown F, et al. Hypoxia augments
cytokine (transforming growth factor-beta (TGF-b) and IL-1)- induced vascular endothelial
growth factor secretion by human synovial fibroblasts. Clin Exp Immunol. 1999;115(176182).
48
[54]. Matsusaka T, Fujikawa K, Nishio Y, Mukaida N, Matsushima K, Kishimoto T, et al.
Transcription factors NF-IL6 and NF-kB synergistically activate transcription of the
inflammatory cytokines, interleukin 6 and interleukin 8. Proc Natl Acad Sci. 1993;90:101937.
[55]. Zhang JL, Peng B. NF-kappa B promotes iNOS and VEGF expression in salivary
gland adenoid cystic carcinoma cells and enhances endothelial cell motility in vitro. Cell
Proliferation. 2009;42(2):150-61.
[56]. Matsuura A, Yamochi W, Hirata K, Kawashima S, Yokoyama M. Stimulatory
interaction between vascular endothelial growth factor and endothelin-1 on each gene
expression. Hypertension. 1998;32:89-95.
[57]. Fujita M, Hayashi I, Yamashina S, Fukamizu A, Itoman M, Majima M. Angiotensin
type 1a receptor signaling-dependent induction of vascular endothelial growth factor in
stroma is relevant to tumor-associated angiogenesis and tumor growth. Carcinogenesis.
2005;26(2):271-9.
[58]. Unemori E, Ferrara N, Bauer E, Amento E. Vascular endothelial growth factor
induces interstitial collagenase expression in human endothelial cells. Journal of cellular
physiology. 1992;153(3):557-62.
[59]. Gelinas D, Bernatchez P, Rollin S, Bazan N, Sirois M. Immediate and delayed VEGFmediated NO synthesis in endothelial cells: Role of PI3K, PKC and PLC pathways. British
Journal of Pharmacology. 2002;137(7):1021-30.
[60]. Kim I, Moon S-O, Hoon Kim S, Jin Kim H, Soon Koh Y, Young Koh G. Vascular
Endothelial Growth Factor Expression of Intercellular Adhesion Molecule 1 (ICAM-1),
Vascular Cell Adhesion Molecule 1 (VCAM-1), and E-selectin through Nuclear Factor-kB
Activation in Endothelial Cells. Journal of Biological Chemistry. 2001;276(10):7614-20.
[61]. Rousseau S, Houle F, Kotanides H, Witte L, Waltenberger J, Landry J, et al. Vascular
Endothelial Growth Factor (VEGF)-driven Actin-based Motility Is Mediated by VEGFR2
and Requires Concerted Activation of Stress-activated Protein Kinase 2 (SAPK2/p38) and
Geldanamycin-sensitive Phosphorylation of Focal Adhesion Kinase. Journal of Biological
Chemistry. 2000;275(14):10661-72.
[62]. Schwock J, Dhani N, Cao MP-J, Zheng J, Clarkson R, Radulovich N, et al. Targeting
Focal Adhesion Kinase with Dominant-Negative FRNK or Hsp90 Inhibitor 17-DMAG
Suppresses Tumor Growth and Metastasis of SiHa Cervical Xenografts. Cancer research.
2009;69(11):4750-9.
[63]. Abedi H, Zachary I. Vascular Endothelial Growth Factor Stimulates Tyrosine
Phosphorylation and Recruitment to New Focal Adhesions of Focal Adhesion Kinase and
Paxillin in Endothelial Cells. Journal of Biological Chemistry. 1997;272(24):15442-51.
[64]. Vignjevic D, Montagnac G. Reorganisation of the dendritic actin network during
cancer cell migration and invasion. Seminars in Cancer Biology. 2008;18(1):12-22.
[65]. Chester M, Tourneux P, Seedorf G, Grover TR, Gien J, Abman SH. Cinaciguat, a
soluble guanylate cyclase activator, causes potent and sustained pulmonary vasodilation in
the ovine fetus. Am J Physiol Lung Cell Mol Physiol. 2009;297(2):318-25.
[66]. Evgenov OV, Kohane DS, Bloch KD, Stasch J-P, Volpato GP, Bellas E, et al. Inhaled
Agonists of Soluble Guanylate Cyclase Induce Selective Pulmonary Vasodilation. Am J
Respir Crit Care Med. 2007;176(11):1138-45.
[67]. Miller L, Nakane M, Hsieh G, Chang R, Kolasa T, Moreland R, et al. A-350619: a
novel activator of soluble guanylyl cyclase. Life Sciences. 2003;72(9):1015-25.
49
[68]. Ku DD, Zaleski JK, Liu S, Brock TA. Vascular endothelial growth factor induces
EDRF-dependent relaxation in coronary arteries. Am J Physiol Heart Circ Physiol.
1993;265(2):586-92.
[69]. Kroll J, Waltenberger J. The Vascular Endothelial Growth Factor Receptor KDR
Activates Multiple Signal Transduction Pathways in Porcine Aortic Endothelial Cells.
Journal of Biological Chemistry. 1997;272(51):32521-7.
[70]. Parenti A, Morbidelli L, Cui X-L, Douglas JG, Hood JD, Granger HJ, et al. Nitric
Oxide Is an Upstream Signal of Vascular Endothelial Growth Factor-induced Extracellular
Signal-regulated KinaseA½ Activation in Postcapillary Endothelium. Journal of Biological
Chemistry. 1998;273(7):4220-6.
[71]. Wheeler-Jones C, Abu-Ghazaleh R, Cospedal R, Houliston RA, Martin J, Zachary I.
Vascular endothelial growth factor stimulates prostacyclin production and activation of
cytosolic phospholipase A2 in endothelial cells via p42/p44 mitogen-activated protein kinase.
FEBS Letters. 1997;420(1):28-32.
[72]. Murohara T, Horowitz JR, Silver M, Tsurumi Y, Chen D, Sullivan A, et al. Vascular
Endothelial Growth Factor/Vascular Permeability Factor Enhances Vascular Permeability
Via Nitric Oxide and Prostacyclin. Circulation. 1998;97(1):99-107.
[73]. Yamamoto T, Horikawa N, Komuro Y, Hara Y. Effect of topical application of a
stable prostacyclin analogue, SM-10902 on wound healing in diabetic mice. European
Journal of Pharmacology. 1996;302(1-3):53-60.
[74]. Tonnesen M, Feng X, Clark R. Angiogenesis in wound healing. J Investig Dermatol
Symp Proc. 2005;5(1):40-6.
[75]. Galiano RD, Tepper OM, Pelo CR, Bhatt KA, Callaghan M, Bastidas N, et al. Topical
Vascular Endothelial Growth Factor Accelerates Diabetic Wound Healing through Increased
Angiogenesis and by Mobilizing and Recruiting Bone Marrow-Derived Cells. Am J Pathol.
2004;164(6):1935-47.
[76]. Voelkel N, Gerber J, McMurtry I, Nies A, Reeves J. Release of vasodilator
prostaglandin, PGI2, from isolated rat lung during vasoconstriction. Circ Res.
1981;48(2):207-13.
[77]. Ellis EF, Wei EP, Kontos HA. Vasodilation of cat cerebral arterioles by
prostaglandins D2, E2, G2, and I2. Am J Physiol Heart Circ Physiol. 1979;237(3):381-5.
[78]. Li B, Ogasawara AK, Yang R, Wei W, He G-W, Zioncheck TF, et al. KDR (VEGF
Receptor 2) Is the Major Mediator for the Hypotensive Effect of VEGF. Hypertension.
2002;39(6):1095-100.
[79]. Hattori K, Dias S, Heissig B, Hackett NR, Lyden D, Tateno M, et al. Vascular
Endothelial Growth Factor and Angiopoietin-1 Stimulate Postnatal Hematopoiesis by
Recruitment of Vasculogenic and Hematopoietic Stem Cells. The Journal of Experimental
Medicine. 2001;193(9):1005-14.
[80]. Abou-Saleh H, Yacoub D, Theoret J-F, Gillis M-A, Neagoe P-E, Labarthe B, et al.
Endothelial Progenitor Cells Bind and Inhibit Platelet Function and Thrombus Formation.
Circulation. 2009;120(22):2230-9.
[81]. Gerber H, Dixit V, Ferrara N. Vascular endothelial growth factor induces expression
of the antiapoptotic proteins Bcl-2 and A1 in vascular endothelial cells. The Journal of
biological chemistry. 1998;273(21):13313-6.
[82]. Gerber H, McMurtrey A, Kowalski J, Yan M, Keyt B, Dixit V, et al. VEGF regulates
endothelial cell survival by the PI3-kinase/Akt signal transduction pathway. Requirement for
Flk-1/KDR activation. J Biol Chem. 1998;273:30366-43.
50
[83]. Gibbons G. Endothelial function as a determinant of vascular function and structure :
A new therapeutic target. The American journal of cardiology. 1997;79:3-8.
[84]. Yanagisawa M, Kurihara H, Kimura S, Tomobe Y, Kobayashi M, Mitsui Y, et al. A
novel potent vasoconstrictor peptide produced by vascular endothelial cells. Nature.
1988;332(6163):411-5.
[85]. Ashrafpour H, Huang N, Neligan PC, Forrest CR, Addison PD, Moses MA, et al.
Vasodilator effect and mechanism of action of vascular endothelial growth factor in skin
vasculature. Am J Physiol Heart Circ Physiol. 2004;286(3):946-54.
[86]. Rosenfeld CR, White RE, Roy T, Cox BE. Calcium-activated potassium channels and
nitric oxide coregulate estrogen-induced vasodilation. Am J Physiol Heart Circ Physiol.
2000;279(1):319-28.
[87]. Takeuchi K, Watanabe H, Tran Q, Ozeki M, Sumi D, Hayashi T, et al. Nitric oxide:
inhibitory effects on endothelial cell calcium signaling, prostaglandin I2. Cardiovascular
research. 2004;62:194-201.
[88]. He H, Venema VJ, Gu X, Venema RC, Marrero MB, Caldwell RB. Vascular
Endothelial Growth Factor Signals Endothelial Cell Production of Nitric Oxide and
Prostacyclin through Flk-1/KDR Activation of c-Src. Journal of Biological Chemistry.
1999;274(35):25130-5.
[89]. Maynard SE, Min J-Y, Merchan J, Lim K-H, Li J, Mondal S, et al. Excess placental
soluble fms-like tyrosine kinase 1 (sFlt1) may contribute to endothelial dysfunction,
hypertension, and proteinuria in preeclampsia. The Journal of Clinical Investigation.
2003;111(5):649-58.
[90]. Advani A, Kelly DJ, Advani SL, Cox AJ, Thai K, Zhang Y, et al. Role of VEGF in
maintaining renal structure and function under normotensive and hypertensive conditions.
Proceedings of the National Academy of Sciences. 2007;104(36):14448-53.
[91]. van der Zee R, Murohara T, Luo Z, Zollmann F, Passeri J, Lekutat C, et al. Vascular
Endothelial Growth Factor/Vascular Permeability Factor Augments Nitric Oxide Release
From Quiescent Rabbit and Human Vascular Endothelium. Circulation. 1997;95(4):1030-7.
[92]. Tsurumi Y, Murohara T, Krasinski K, Chen D, Witzenbichler B, Kearney M, et al.
Reciprocal relation between VEGF and NO in the regulation of endothelial integrity. Nat
Med. 1997;3(8):879-86.
[93]. Abraham D, Hofbauer R, Schafer R, Blumer R, Paulus P, Miksovsky A, et al.
Selective Downregulation of VEGF-A165, VEGF-R1, and Decreased Capillary Density in
Patients with Dilative but Not Ischemic Cardiomyopathy. Circ Res. 2000;87:644.
[94]. Roberts W, Palade G. Increased microvascular permeability and endothelial
fenestration induced by vascular endothelial growth factor. J Cell Sci. 1995;108:2369-79.
[95]. Yang R, Ogasawara AK, Zioncheck TF, Ren Z, He G-W, DeGuzman GG, et al.
Exaggerated Hypotensive Effect of Vascular Endothelial Growth Factor in Spontaneously
Hypertensive Rats. Hypertension. 2002;39(3):815-20.
[96]. Marko SB, Damon DH. VEGF promotes vascular sympathetic innervation. Am J
Physiol Heart Circ Physiol. 2008;294(6):2646-52.
[97]. Kawasaki T, Bekku Y, Suto F, Kitsukawa T, Taniguchi M, Nagatsu I, et al.
Requirement of neuropilin 1-mediated Sema3A signals in patterning of the sympathetic
nervous system. Development. 2002;129:671-80.
[98]. Ferrara N, Gerber H, Lecouter J. The biology of VEGF and its receptors. Nature
Medicine. Nature Medicine. 2003;9:669-76.
51
[99]. Neufeld G, Cohen T, Shraga N, Lange T, Kessler O, Herzog Y. The Neuropilins:
Multifunctional Semaphorin and VEGF Receptors that Modulate Axon Guidance and
Angiogenesis. Trends in Cardiovascular Medicine. 2002;12(1):13-9.
[100]. Clark D. Effects of immunosympathectomy on development of high blood pressure in
genetically hypertensive rats. Circ Res. 1971;28:330-6.
[101]. Folkman J. Tumor angiogenesis: therapeutic implications. N Engl J Med.
1971;285:1182-6.
[102]. Timar J, Paku S, Tovari J, Dome B. Rationale of antiangiogenic therapy. Magy
Onkol. 2006;50(2):141-51.
[103]. Leung D, Cachianes G, Kuang W, Goeddel D, Ferrera N. Vascular endothelial growth
factor is a secreted angiogenic mitogen. Science. 1989;246:1306-9.
[104]. Plouet J, Schilling, J. & Gospodarowicz, D. Isolation and characterization of a newly
identified endothelial cell mitogen produced by TtT20 cells. EMBO Journal. 1989:3801-8.
[105]. Gerber HP, Ferrara N. Pharmacology and Pharmacodynamics of Bevacizumab as
Monotherapy or in Combination with Cytotoxic Therapy in Preclinical Studies. Cancer Res.
2005 February 1, 2005;65(3):671-80.
[106]. Kamba T, McDonald D. Mechanisms of adverse effects of anti-VEGF therapy for
cancer. The British Journal of Cancer. 2007;96(12):1788-95.
[107]. Escudier B, Eisen T, Stadler W, Szczylik C, Oudard S, Siebels M, et al. Sorafenib in
advanced clear-cell renal-cell carcinoma. N Engl J Med 2007;356:125-34.
[108]. Sternberg CN, Davis ID, Mardiak J, Szczylik C, Lee E, Wagstaff J, et al. Pazopanib in
Locally Advanced or Metastatic Renal Cell Carcinoma: Results of a Randomized Phase III
Trial. J Clin Oncol. 2010;28(6):1061-8.
[109]. Goss GD, Arnold A, Shepherd FA, Dediu M, Ciuleanu T-E, Fenton D, et al.
Randomized, Double-Blind Trial of Carboplatin and Paclitaxel With Either Daily Oral
Cediranib or Placebo in Advanced Non-Small-Cell Lung Cancer: NCIC Clinical Trials Group
BR24 Study. J Clin Oncol. 2010;28(1):49-55.
[110]. Wood J, Bold G, Buchdunger E, Cozens R, Ferrari S, Frei J. PTK787/ZK 222584, a
novel and potent inhibitor of vascular endothelial growth factor receptor tyrosine kinases,
impairs vascular endothelial growth factor-induced responses and tumor growth after oral
administration. Cancer research. 2000;60(8):2178-89.
[111]. Langenberg MH, Witteveen PO, Lankheet NA, Roodhart JM, Rosing H, Van den
Heuvel IJ, et al. Phase 1 Study of Combination Treatment with PTK 787/ZK 222584 and
Cetuximab for Patients with Advanced Solid Tumors: Safety, Pharmacokinetics,
Pharmacodynamics Analysis. Neoplasia. 2010;12(2):206-13.
[112]. Huang J, Frischer J, Serur A, Kadenhe A, Yokoi A, McCrudden K. Regression of
established tumors and metastases by potent vascular endothelial growth factor blockade.
Proceedings of the National Academy of Sciences of the United States of America.
2003;100(13):7785-90.
[113]. Lockhart AC, Rothenberg ML, Dupont J, Cooper W, Chevalier P, Sternas L, et al.
Phase I Study of Intravenous Vascular Endothelial Growth Factor Trap, Aflibercept, in
Patients With Advanced Solid Tumors. J Clin Oncol.28(2):207-14.
[114]. McCarty M, Wey J, Stoeltzing O, Liu W, Fan F, Bucana C. ZD6474, a vascular
endothelial growth factor receptor tyrosine kinase inhibitor with additional activity against
epidermal growth factor receptor tyrosine kinase, inhibits orthotopic growth and angiogenesis
of gastric cancer. Molecular cancer therapeutics. 2004;3(9):1041-8.
[115]. Yang S WJ, Zuo Y, Tan L, Jia H, Yan H, Zhu X, Zeng M, Ma J, Huang W. ZD6474,
a Small Molecule Tyrosine Kinase Inhibitor, Potentiates the Anti-Tumor and Anti-Metastasis
52
Effects of Radiation for Human Nasopharyngeal Carcinoma. Current Cancer Drug Targets.
2010;Epub ahead of print.
[116]. Polverino A, Coxon A, Starnes C, Diaz Z, DeMelfi T, Wang L. AMG 706, an oral,
multikinase inhibitor that selectively targets vascular endothelial growth factor, plateletderived growth factor, and Kit receptors, potently inhibits angiogenesis and induces
regression in tumor xenografts. Cancer research. 2006;66(17):8715-21.
[117]. Blumenschein GR, Reckamp K, Stephenson GJ, O'Rourke T, Gladish G, McGreivy J,
et al. Phase 1b Study of Motesanib, an Oral Angiogenesis Inhibitor, in Combination with
Carboplatin/Paclitaxel and/or Panitumumab for the Treatment of Advanced Non Small Cell
Lung Cancer. Clinical Cancer Research. 2010;16(1):279-90.
[118]. Wilmes LJ, Pallavicini MG, Fleming LM, Gibbs J, Wang D, Li K-L, et al. AG013736, a novel inhibitor of VEGF receptor tyrosine kinases, inhibits breast cancer growth
and decreases vascular permeability as detected by dynamic contrast-enhanced magnetic
resonance imaging. Magnetic Resonance Imaging. 2007;25(3):319-27.
[119]. Sharma S, Abhyankar V, Burgess RE, Infante J, Trowbridge RC, Tarazi J, et al. A
phase I study of axitinib (AG-013736) in combination with bevacizumab plus chemotherapy
or chemotherapy alone in patients with metastatic colorectal cancer and other solid tumors.
Annals of Oncology. 2010;21(2):297-304.
[120]. Dome B, Hendrix MJC, Paku S, Tovari J, Timar J. Alternative Vascularization
Mechanisms in Cancer: Pathology and Therapeutic Implications. Am J Pathol.
2007;170(1):1-15.
[121]. Hurwitz H, Fehrenbacher L, Novotny W, Cartwright T, Hainsworth J, Heim W, et al.
Bevacizumab plus Irinotecan, Fluorouracil, and Leucovorin for Metastatic Colorectal Cancer.
N Engl J Med. 2004;350(23):2335-42.
[122]. Grover TR, Parker TA, Zenge JP, Markham NE, Kinsella JP, Abman SH. Intrauterine
hypertension decreases lung VEGF expression and VEGF inhibition causes pulmonary
hypertension in the ovine fetus. Am J Physiol Lung Cell Mol Physiol. 2003;284(3):508-17.
[123]. Partovian C, Adnot S, Eddahibi S, Teiger E, Levame M, Dreyfus P, et al. Heart and
lung VEGF mRNA expression in rats with monocrotaline- or hypoxia-induced pulmonary
hypertension. Am J Physiol Heart Circ Physiol. 1998;275(6):1948-56.
[124]. Kojima T, Miyachi S, Sahara Y, Nakai K, Okamoto T, Hattori K, et al. The
relationship between venous hypertension and expression of vascular endothelial growth
factor: hemodynamic and immunohistochemical examinations in a rat venous hypertension
model. Surgical Neurology. 2007;68(3):277-84.
[125]. Zhu Y, Lawton MT, Du R, Shwe Y, Chen Y, Shen F, et al. Expression of Hypoxiainducible Factor-1 and Vascular Endothelial Growth Factor in Response to Venous
Hypertension. Neurosurgery. 2006;59(3):687-96
[126]. Svendsen M, Lykke J, Werther K, Christensen I, Nielsen H. Concentrations of VEGF
and VEGFR1 in paired tumor arteries and veins in patients with rectal cancer. Oncology
research. 2004;14(11-12):611-5.
[127]. Dong J, Grunstein J, Tejada M, Peale F, Frantz G, Liang W-C, et al. VEGF-null cells
require PDGFR α signaling-mediated stromal fibroblast recruitment for tumorigenesis. Embo
J. 2004;23(14):2800-10.
[128]. Sandler A, Gray R, Perry MC, Brahmer J, Schiller JH, Dowlati A, et al. PaclitaxelCarboplatin Alone or with Bevacizumab for Non-Small-Cell Lung Cancer. N Engl J Med.
2006;355(24):2542-50.
53
[129]. El-Rayes BF, Patel B, Zalupski M, Hammad N, Shields A, Heilbrun L, et al. A phase
II study of bevacizumab, docetaxel, and oxaliplatin in gastric and GEJ cancer. J Clin Oncol
(Meeting Abstracts). 2009;27(15S):4563.
[130]. Dent P, Grant S. Pharmacologic interruption of the mitogen-activated extracellular
regulated kinase/mitogen activated protein kinase signal transduction pathway: Potential role
in promoting cytotoxic drug action. Clin Can Res. 2001;7:792-8.
[131]. Wang X, Martindale J, Holbrook N. Requirement of ERK activation in cisplatininduced apoptosis. J Biol Chem. 2000;275:39435-43.
[132]. Johnson DH, Fehrenbacher L, Novotny WF, Herbst RS, Nemunaitis JJ, Jablons DM,
et al. Randomized Phase II Trial Comparing Bevacizumab Plus Carboplatin and Paclitaxel
With Carboplatin and Paclitaxel Alone in Previously Untreated Locally Advanced or
Metastatic Non-Small-Cell Lung Cancer. J Clin Oncol. 2004;22(11):2184-91.
[133]. Sobrero A, Ackland S, Clarke S, Perez-Carrión R, Chiara S, Gapski J, et al. Phase
IV Study of Bevacizumab in Combination with Infusional Fluorouracil, Leucovorin and
Irinotecan (FOLFIRI) in First-Line Metastatic Colorectal Cancer. Oncology. 2009;77(2):1139.
[134]. Vogelzang N. Continuous infusion chemotherapy: A critical review. J Clin Oncol.
1984;2:1289-304.
[135]. Cwikiel M, Zhang B, Eskilsson J, Wieslander J, Albertsson M. The influence of 5fluorouracil on the endothelium in small arteries. An electron microscopic study in rabbits.
Scanning Microscopy. 1995;9(2):561-76.
[136]. Cwikiel M, Eskilsson J, Albertsson M, Stavenow L. The influence of 5-fluorouracil
and methotrexate on vascular endothelium. An experimental study using endothelial cells in
the culture. Annals of Oncology. 1996;7(7):731-7.
[137]. Herbst RS, O'Neill VJ, Fehrenbacher L, Belani CP, Bonomi PD, Hart L, et al. Phase
II Study of Efficacy and Safety of Bevacizumab in Combination With Chemotherapy or
Erlotinib Compared With Chemotherapy Alone for Treatment of Recurrent or Refractory
Non Small-Cell Lung Cancer. J Clin Oncol. 2007;25(30):4743-50.
[138]. Adjei AA, Molina JR, Mandrekar SJ, Marks R, Reid JR, Croghan G, et al. Phase I
Trial of Sorafenib in Combination with Gefitinib in Patients with Refractory or Recurrent
Non Small Cell Lung Cancer. Clinical Cancer Research. 2007;13(9):2684-91.
[139]. Gospodarowicz D, Abraham JA, Schilling J. Isolation and characterization of a
vascular endothelial cell mitogen produced by pituitary-derived folliculo stellate cells.
Proceedings of the National Academy of Sciences of the United States of America.
1989;86(19):7311-5.
[140]. Carterson AJ, Honer zu Bentrup K, Ott CM, Clarke MS, Pierson DL, Vanderburg CR,
et al. A549 Lung Epithelial Cells Grown as Three-Dimensional Aggregates: Alternative
Tissue Culture Model for Pseudomonas aeruginosa Pathogenesis. Infect Immun.
2005;73(2):1129-40.
[141]. Okayama N, Fowler M, Jennings S, Patel P, Specian R, Alexander B, et al.
Characterization of JOK-1, a human gastric epithelial cell line. In Vitro Cellular &
Developmental Biology - Animal. 2000;36(4):228-34.
[142]. Goon PKY, Lip GYH, Boos CJ, Stonelake PS, Blann AD. Circulating Endothelial
Cells, Endothelial Progenitor Cells, and Endothelial Microparticles in Cancer. Neoplasia.
2006;8(2):79-88.
[143]. Mancuso P, Burlini A, Pruneri G, Goldhirsch A, Martinelli G, Bertolini F. Resting
and activated endothelial cells are increased in the peripheral blood of cancer patients. Blood.
2001;97(11):3658-61.
54
[144]. Pascaud M-A, Griscelli F, Raoul W, Marcos E, Opolon P, Raffestin B, et al. Lung
Overexpression of Angiostatin Aggravates Pulmonary Hypertension in Chronically Hypoxic
Mice. Am J Respir Cell Mol Biol. 2003;29(4):449-57.
[145]. Mancuso P, Colleoni M, Calleri A, Orlando L, Maisonneuve P, Pruneri G, et al.
Circulating endothelial-cell kinetics and viability predict survival in breast cancer patients
receiving metronomic chemotherapy. Blood. 2006;108(2):452-9.
[146]. Bono P, Elfving H, Utriainen T, A sterlund P, Saarto T, Alanko T, et al. Hypertension
and clinical benefit of bevacizumab in the treatment of advanced renal cell carcinoma. Annals
of Oncology. 2009;20(2):393-4.
[147]. Smirnov DA, Foulk BW, Doyle GV, Connelly MC, Terstappen LWMM, O'Hara SM.
Global Gene Expression Profiling of Circulating Endothelial Cells in Patients with Metastatic
Carcinomas. Cancer Res. 2006;66(6):2918-22.
[148]. Kim JJ, Vaziri SA, Elson P, Rini BI, Ganapathi MK, Ganapathi R. VEGF single
nucleotide polymorphisms (SNPs) and correlation to sunitinib-induced hypertension (HTN)
in metastatic renal cell carcinoma (mRCC) patients (pts). J Clin Oncol (Meeting Abstracts).
2009;27(15S):5005.
[149]. Schneider BP, Wang M, Radovich M, Sledge GW, Badve S, Thor A, et al.
Association of Vascular Endothelial Growth Factor and Vascular Endothelial Growth Factor
Receptor-2 Genetic Polymorphisms With Outcome in a Trial of Paclitaxel Compared With
Paclitaxel Plus Bevacizumab in Advanced Breast Cancer: ECOG 2100. J Clin Oncol.
2008;26(28):4672-8.
[150]. Poltorak Z, Cohen T, Sivan R, Kandelis Y, Spira G, Vlodavsky I, et al. VEGF145, a
Secreted Vascular Endothelial Growth Factor Isoform That Binds to Extracellular Matrix.
Journal of Biological Chemistry. 1997;272(11):7151-8.
[151]. Jingjing L, Xue Y, Agarwal N, Roque R. Human Muller cells express VEGF183, a
novel spliced variant of vascular endothelial growth factor. Invest Ophthalmol Vis Sci.
1999;40(3):752-9.
[152]. Shima D, Kuroki M, Deutsch U, Ng Y, Adamis A, D’Amore P. The mouse gene for
vascular endothelial growth factor: Genomic structure, definition of the transcriptional unit
and characterization of transcriptional and post-transcriptional regulatory sequences. J Biol
Chem. 1996;271:3877-83.
[153]. Tischer E, Mitchell R, Hartman T, Silva M, Gospodarowicz D, Fiddes JC, et al. The
human gene for vascular endothelial growth factor. Multiple protein forms are encoded
through alternative exon splicing. Journal of Biological Chemistry. 1991;266(18):11947-54.
[154]. Scartozzi M, Galizia E, Chiorrini S, Giampieri R, Berardi R, Pierantoni C, et al.
Arterial hypertension correlates with clinical outcome in colorectal cancer patients treated
with first-line bevacizumab. Annals of Oncology. 2009;20(2):227-30.
[155]. Hughes B. Cancer: Tuning anti-angiogenesis. Nat Rev Drug Discov. 2008;7(1):18-9.
[156]. Mancuso M, Davis R, Norberg S, O’Brien S, Sennino B, Nakahara T, et al. Rapid
vascular regrowth in tumors after reversal of VEGF inhibition. J Clin Invest 2006;116:261021.
[157]. Butowski, Chang. Glial tumours: The current state of scientific knowledge. Clinical
Neurosurgery: Lippincott Williams & Wilkins; 2006. p. 110.
[158]. Eguchi S, Dempsey PJ, Frank GD, Motley ED, Inagami T. Activation of MAPKs by
Angiotensin II in Vascular Smooth Muscle Cells. Journal of Biological Chemistry.
2001;276(11):7957-62.
55
[159]. Kishi T, Hirooka Y, Sunagawa K. The small G protein Ras and Ras/MAPK/ERK
pathway are up-regulated in the rostral ventrolateral medulla of stroke-prone spontaneously
hypertensive rats. FASEB J. 2008;22(1):1234.4.
[160]. Della Rocca GJ, van Biesen T, Daaka Y, Luttrell DK, Luttrell LM, Lefkowitz RJ.
Ras-dependent Mitogen-activated Protein Kinase Activation by G Protein-coupled Receptors.
Journal of Biological Chemistry. 1997;272(31):19125-32.
[161]. Basu S, Bayoumy S, Zhang Y, Lozano J, Kolesnick R. BAD Enables Ceramide to
Signal Apoptosis via Ras and Raf-1. Journal of Biological Chemistry. 1998;273(46):3041926.
[162]. Wang H-G, Pathan N, Ethell IM, Krajewski S, Yamaguchi Y, Shibasaki F, et al.
Ca2+-Induced Apoptosis Through Calcineurin Dephosphorylation of BAD. Science.
1999;284(5412):339-43.
[163]. Kitada S, Krajewska M, Zhang X, Scudiero D, Zapata J, Wang H, et al. Expression
and location of pro-apoptotic Bcl-2 family protein BAD in normal human tissues and tumor
cell lines. Am J Pathol. 1998;152(1):51-61.
[164]. Costanzo A, Moretti F, Burgio V, Bravi C, Guido F, Levrero M, et al. Endothelial
activation by angiotensin II through NFκB and p38 pathways: Involvement of NFκBInducible kinase (NIK), free oxygen radicals, and selective inhibition by aspirin. Journal of
cellular physiology. 2003;195(3):402-10.
[165]. Muthalif MM, Karzoun NA, Gaber L, Khandekar Z, Benter IF, Saeed AE, et al.
Angiotensin II-Induced Hypertension : Contribution of Ras GTPase/Mitogen-Activated
Protein Kinase and Cytochrome P450 Metabolites. Hypertension. 2000;36(4):604-9.
[166]. Mitra AK, Gao L, Zucker IH. Angiotensin II induces upregulation of AT1 receptors
via the sequential activation of transcription factors NFkB, Elk-1 and AP-1 in Cath.a cells.
FASEB J (Meeting Abstracts). 2009;23:609.15.
[167]. Carloni V, Pinzani M, Giusti S, Romanelli RG, Parola M, Bellomo G, et al. Tyrosine
phosphorylation of focal adhesion kinase by PDGF is dependent on Ras in human hepatic
stellate cells. Hepatology. 2000;31(1):131-40.
[168]. Yi XP, Wang X, Gerdes AM, Li F. Subcellular Redistribution of Focal Adhesion
Kinase and Its Related Nonkinase in Hypertrophic Myocardium. Hypertension.
2003;41(6):1317-23.
[169]. Xiaolei Z, Shenhong W, William LD, Chirag RP. Risks of Proteinuria and
Hypertension With Bevacizumab, an Antibody Against Vascular Endothelial Growth Factor:
Systematic Review and Meta-Analysis. American journal of kidney diseases.
2007;49(2):186-93.
[170]. Eremina V, Sood M, Haigh J, Nagy A, Lajoie G, Ferrara N, et al. Glomerular-specific
alterations of VEGF-A expression lead to distinct congenital and acquired renal diseases. J
Clin Invest. 2003;111:707-16.
[171]. Sugimoto H, Hamano Y, Charytan D, Cosgrove D, Kieran M, Sudhakar A, et al.
Neutralization of Circulating Vascular Endothelial Growth Factor (VEGF) by Anti-VEGF
Antibodies and Soluble VEGF Receptor 1 (sFlt-1) Induces Proteinuria. Journal of Biological
Chemistry. 2003;278(15):12605-8.
[172]. Hassane I, Christophe M, Jean Philippe S, Franasois G, David K, Jean Charles S.
VEGF signalling inhibition-induced proteinuria: Mechanisms, significance and management.
European journal of cancer (Oxford, England : 1990).46(2):439-48.
[173]. Weir MR. Microalbuminuria and Cardiovascular Disease. Clin J Am Soc Nephrol.
2007;2(3):581-90.
56
[174]. Skillings JR, Johnson DH, Miller K, Kabbinavar F, Bergsland E, Holmgren E, et al.
Arterial thromboembolic events (ATEs) in a pooled analysis of 5 randomized, controlled
trials (RCTs) of bevacizumab (BV) with chemotherapy. J Clin Oncol (Meeting Abstracts).
2005;23(16S):3019.
[175]. TARASEVICIENE-STEWART L, KASAHARA Y, ALGER L, HIRTH P, MC
MAHON G, WALTENBERGER J, et al. Inhibition of the VEGF receptor 2 combined with
chronic hypoxia causes cell death-dependent pulmonary endothelial cell proliferation and
severe pulmonary hypertension. FASEB J. 2001;15(2):427-38.
[176]. Kilickap S, Abali H, Celik I. Bevacizumab, bleeding, thrombosis, and warfarin. J Clin
Oncol. 2003;21:3542.
[177]. Kenji S, Tomohiro N. Interplay between ADAMTS13 and von Willebrand factor in
inherited and acquired thrombotic microangiopathies. Seminars in hematology.
2005;42(1):56-62.
[178]. Xu Z, Yu Y, Duh EJ. Vascular Endothelial Growth Factor Upregulates Expression of
ADAMTS1 in Endothelial Cells through Protein Kinase C Signaling. Invest Ophthalmol Vis
Sci. 2006;47(9):4059-66.
[179]. Tam BYY, Wei K, Rudge JS, Hoffman J, Holash J, Park S-k, et al. VEGF modulates
erythropoiesis through regulation of adult hepatic erythropoietin synthesis. Nat Med.
2006;12(7):793-800.
[180]. Mechtcheriakova D, Wlachos A, Holzmuller H, Binder BR, Hofer E. Vascular
Endothelial Cell Growth Factor-Induced Tissue Factor Expression in Endothelial Cells Is
Mediated by EGR-1. Blood. 1999;93(11):3811-23.
[181]. Mackman N. Role of Tissue Factor in Hemostasis, Thrombosis, and Vascular
Development. Arterioscler Thromb Vasc Biol. 2004;24(6):1015-22.
[182]. Kerkela R, Grazette L, Yacobi R, Iliescu C, Patten R, Beahm C, et al. Cardiotoxicity
of the cancer therapeutic agent imatinib mesylate. Nat Med. 2006;12(8):908-16.
[183]. Chu TF, Rupnick MA, Kerkela R, Dallabrida SM, Zurakowski D, Nguyen L, et al.
Cardiotoxicity associated with tyrosine kinase inhibitor sunitinib. The Lancet.
2007;370(9604):2011-9.
[184]. Force T, Krause DS, Van Etten RA. Molecular mechanisms of cardiotoxicity of
tyrosine kinase inhibition. Nat Rev Cancer. 2007;7(5):332-44.
[185]. Khakoo AY, Kassiotis CM, Tannir N, Plana JC, Halushka M, Bickford C, et al. Heart
failure associated with sunitinib malate. Cancer. 2008;112(11):2500-8.
[186]. Seidman A, Hudis C, Pierri MK, Shak S, Paton V, Ashby M, et al. Cardiac
Dysfunction in the Trastuzumab Clinical Trials Experience. J Clin Oncol. 2002;20(5):121521.
[187]. Miller K, Wang M, Gralow J, Dickler M, Cobleigh M, Perez EA, et al. Paclitaxel plus
Bevacizumab versus Paclitaxel Alone for Metastatic Breast Cancer. N Engl J Med.
2007;357(26):2666-76.
[188]. Miller KD, Chap LI, Holmes FA, Cobleigh MA, Marcom PK, Fehrenbacher L, et al.
Randomized Phase III Trial of Capecitabine Compared With Bevacizumab Plus Capecitabine
in Patients With Previously Treated Metastatic Breast Cancer. J Clin Oncol. 2005;23(4):7929.
[189]. Izumiya Y, Shiojima I, Sato K, Sawyer DB, Colucci WS, Walsh K. Vascular
Endothelial Growth Factor Blockade Promotes the Transition From Compensatory Cardiac
Hypertrophy to Failure in Response to Pressure Overload. Hypertension. 2006;47(5):887-93.
57
[190]. Shiojima I, Sato K, Izumiya Y, Schiekofer S, Ito M, Liao R, et al. Disruption of
coordinated cardiac hypertrophy and angiogenesis contributes to the transition to heart
failure. The Journal of Clinical Investigation. 2005;115(8):2108-18.
[191]. Mir O, Ropert S, Alexandre J, Goldwasser F. Hypertension as a surrogate marker for
the activity of anti-VEGF agents. Annals of Oncology. 2009;20(5):967-70.
[192]. Azizi M, Chedid A, Oudard S. Home Blood-Pressure Monitoring in Patients
Receiving Sunitinib. N Engl J Med. 2008;358(1):95-7.
[193]. Henriksen KJ, Meehan SM, Chang A. Non-neoplastic renal diseases are often
unrecognized in adult tumor nephrectomy specimens: a review of 246 cases. American
Journal of Surgical Pathology. 2007;31(11):1703-8.
[194]. Laham RJ, Li J, Tofukuji M, Post M, Simons M, Sellke FW. Spatial Heterogeneity in
VEGF-induced Vasodilation: VEGF Dilates Microvessels but Not Epicardial and Systemic
Arteries and Veins. Annals of Vascular Surgery. 2003;17(3):245-52.
[195]. Schiffrin EL. Vascular stiffening and arterial compliance. Am J Hypertens.
2004;17(3):39-48.
[196]. Giannattasio C, Failla M, Mangoni A, Scandola L, Fraschini N, Mancia G. Evaluation
of arterial compliance in humans. Clin Exp Hypertens. 1996;18(3-4):347-62.
[197]. Wilkinson IB, Qasem A, McEniery CM, Webb DJ, Avolio AP, Cockcroft JR. Nitric
Oxide Regulates Local Arterial Distensibility In Vivo. Circulation. 2002;105(2):213-7.
[198]. Taniwaki H, Kawagishi T, Emoto M, Shoji T, Hosoi M, Kogawa K, et al. Association
of ACE gene polymorphism with arterial stiffness in patients with type 2 diabetes. Diabetes
Care. 1999;22(11):1858-64.
[199]. Giannattasio C, Mangoni AA, Failla M, Stella ML, Carugo S, Bombelli M, et al.
Combined Effects of Hypertension and Hypercholesterolemia on Radial Artery Function.
Hypertension. 1997;29(2):583-6.
[200]. Hope SA, Hughes AD. Drug effects on the mechanical properties of large arteries in
humans. Clinical and Experimental Pharmacology and Physiology. 2007;34(7):688-93.
[201]. McVeigh GE, Bank AJ, Cohn JN. Arterial Compliance. Cardiovascular Medicine:
Springer London; 2007. p. 1811-31.
[202]. Cambonie G, Comte B, Yzydorczyk C, Ntimbane T, Germain N, Le NLO, et al.
Antenatal antioxidant prevents adult hypertension, vascular dysfunction, and microvascular
rarefaction associated with in utero exposure to a low-protein diet. Am J Physiol Regul Integr
Comp Physiol. 2007;292(3):1236-45.
[203]. Steeghs N, Gelderblom H, Roodt Jot, Christensen O, Rajagopalan P, Hovens M, et al.
Hypertension and Rarefaction during Treatment with Telatinib, a Small Molecule
Angiogenesis Inhibitor. Clinical Cancer Research. 2008;14(11):3470-6.
[204]. Paintal A. Cardiovascular receptors. In: Handbook of Sensory Physiology. Berlin:
Springer Verlag. 1972;III/1:1-45.
[205]. Heymans C, E.Neil. Reflexogenic areas in the cardiovascular system. Perspect Biol
Med. 1960;3:409-17.
[206]. Adams W. The Comparative Morphology of the Carotid Body and Carotid Sinus.
Springfield, Illinois: Charles C. Thomas; 1958.
[207]. Boss J, Green J. The histology of the common carotid baroreceptor areas of the cat
Circulation Res. 1956;4:12-7.
[208]. Kubo T, Asari T, Yamaguchi H, Fukumori R. Baroreceptor Activation Causes
Release of Acetylcholine in the Rostral Ventrolateral Medulla of the Rat. Clinical and
Experimental Hypertension. 1998;20(2):245-57.
58
[209]. Thrasher TN. Baroreceptors, baroreceptor unloading, and the long-term control of
blood pressure. Am J Physiol Regul Integr Comp Physiol. 2005;288(4):819-27.
[210]. Altiok S, Batt D, Altiok N, Papautsky A, Downward J, Roberts TM, et al. Heregulin
Induces Phosphorylation of BRCA1 through Phosphatidylinositol 3-Kinase/AKT in Breast
Cancer Cells. Journal of Biological Chemistry. 1999;274(45):32274-8.
[211]. Datta SR, Brunet A, Greenberg ME. Cellular survival: a play in three Akts. Genes &
Development. 1999;13(22):2905-27.
[212]. Galetic I, Andjelkovic M, Meier R, Brodbeck D, Park J, Hemmings BA. Mechanism
of Protein Kinase B Activation by Insulin/Insulin-Like Growth Factor-1 Revealed by Specific
Inhibitors of Phosphoinositide 3-Kinase-Significance for Diabetes and Cancer - putting JAKs
on the kinase MAP. Pharmacology and Therapeutics. 1999;82:409-25.
[213]. Montagnani M, Chen H, Barr VA, Quon MJ. Insulin-stimulated Activation of eNOS
Is Independent of Ca2+ but Requires Phosphorylation by Akt at Ser1179. Journal of
Biological Chemistry. 2001;276(32):30392-8.
[214]. Zhou BP, Liao Y, Xia W, Spohn B, Lee M-H, Hung M-C. Cytoplasmic localization of
p21Cip1/WAF1 by Akt-induced phosphorylation in HER-2/neu-overexpressing cells. Nat
Cell Biol. 2001;3(3):245-52.
[215]. Zimmermann S, Moelling K. Phosphorylation and Regulation of Raf by Akt (Protein
Kinase B). Science. 1999;286(5445):1741-4.
[216]. Begum N, Ragolia L, Rienzie J, McCarthy M, Duddy N. Regulation of Mitogenactivated Protein Kinase Phosphatase-1 Induction by Insulin in Vascular Smooth Muscle
Cells. The Journal of biological chemistry. 1998;273(39):25164-70.
[217]. Fulton D, Gratton J, McCabe T, Fontana J, Fujio Y, Walsh K, et al. Regulation of
endothelium-derived nitric oxide production by the protein kinase Akt. Nature.
1999;399:597-601.
[218]. Stryer L. Cyclic GMP Cascade of Vision. Annual Review of Neuroscience.
1986;9(1):87-119.
[219]. Wright SN. Irreversible Block of Human Heart (hH1) Sodium Channels by the Plant
Alkaloid Lappaconitine. Molecular Pharmacology. 2001;59(2):183-92.
[220]. Dugas M, Honerjäger P, Masslich U. Tetrodotoxin block of single germitrineactivated sodium channels in cultured rat cardiac cells. The Journal of Physiology.
1989;411(1):611-26.
[221]. Terlau H, Heinemann SH, Stühmer W, Pusch M, Conti F, Imoto K, et al. Mapping the
site of block by tetrodotoxin and saxitoxin of sodium channel II. FEBS Letters. 1991;293(12):93-6.
[222]. Fozzard H, Lee P, Lipkind G. Mechanism of local anesthetic drug action on voltagegated sodium channels. Current Pharmaceutical Design. 2005;11(21):2671-86.
[223]. Kodama I, Honjo H, Kamiya K, Toyama J. Two types of sodium channel block by
class-I antiarrhythmic drugs studied by using of action potential in single ventricular
myocytes. Journal of Molecular and Cellular Cardiology. 1990;22(1):1-12.
[224]. Kyle DJ, Ilyin VI. Sodium Channel Blockers. Journal of Medicinal Chemistry.
2007;50(11):2583-8.
[225]. Alp NJ, Channon KM. Regulation of Endothelial Nitric Oxide Synthase by
Tetrahydrobiopterin in Vascular Disease. Arterioscler Thromb Vasc Biol. 2004;24(3):413-20.
[226]. Michel JB, Feron O, Sacks D, Michel T. Reciprocal Regulation of Endothelial Nitricoxide Synthase by Ca2+-Calmodulin and Caveolin. Journal of Biological Chemistry.
1997;272(25):15583-6.
59
[227]. Fukuda Y, Teragawa H, Matsuda K, Yamagata T, Matsuura H, Chayama K.
Tetrahydrobiopterin restores endothelial function of coronary arteries in patients with
hypercholesterolaemia. Heart. 2002;87(3):264-9.
[228]. D'Uscio LV, Milstien S, Richardson D, Smith L, Katusic ZS. Long-Term Vitamin C
Treatment Increases Vascular Tetrahydrobiopterin Levels and Nitric Oxide Synthase
Activity. Circ Res. 2003;92(1):88-95.
[229]. Duch DS, Woolf JH, Nichol CA, Davidson JR, Garbutt JC. Urinary excretion of
bioterin and neopterin in psychiatric disorders. Psychiatry Research. 1984;11(2):83-9.
[230]. Nishida A, Miyaoka T, Inagaki T, Horiguchi J. New Approaches to Antidepressant
Drug Design: Cytokine-Regulated Pathways. Current Pharmaceutical Design. 2009;15:16837.
[231]. Safran M, Kaelin WG. HIF hydroxylation and the mammalian oxygen-sensing
pathway. The Journal of Clinical Investigation. 2003;111(6):779-83.
[232]. Thirunavukkarasu M, Akita Y, Samuel SM, Zhan L, Huang C-K, Gaestel M, et al.
Abstract 5564: Sequencial Activation of VEGF/Flk-1/MKK2/NFkappaB Signaling in
Ischemic Preconditioning Induced Neovascularization: A Study with Flk-1+/- and MKK2-/Knockout Mice. Circulation. 2008;118:575-6.
[233]. Shimojo N, Jesmin S, Hattori Y, Maeda S, Miyauchi T, Aonuma K. Abstract 934:
Contributory Role of VEGF Overexpression in Endothelin-1-induced Cardiomyocyte
Hypertrophy: Involvement of Hyopoxia Inducible Factor. Circulation. 2007;116:184.
[234]. Wu Y, Zhang Q, Ann DK, Akhondzadeh A, Duong HS, Messadi DV, et al. Increased
vascular endothelial growth factor may account for elevated level of plasminogen activator
inhibitor-1 via activating ERK1/2 in keloid fibroblasts. Am J Physiol Cell Physiol.
2004;286(4):905-12.
[235]. Mandriota SJ, Seghezzi G, Vassalli J-D, Ferrara N, Wasi S, Mazzieri R, et al.
Vascular Endothelial Growth Factor Increases Urokinase Receptor Expression in Vascular
Endothelial Cells. Journal of Biological Chemistry. 1995;270(17):9709-16.
[236]. Kroon M, Koolwijk P, Vermeer M, Van V, Hinsbergh V. Vascular endothelial growth
factor enhances the expression of urokinase receptor in human endothelial cells via protein
kinase C activation. Thromb Haemost. 2001;85(2):296-302.
[237]. Mignatti P, Tsuboi R, Robbins E, Rifkin DB. In vitro angiogenesis on the human
amniotic membrane: requirement for basic fibroblast growth factor-induced proteinases.
Journal of Cell Biology. 1989;108(2):671-82.
[238]. Pekala P, Marlow M, Heuvelman D, Connolly D. Regulation of Hexose Transport in
Aortic Endothelial Cells by Vascular Permeability Factor and Tumor Necrosis Factor-at, but
Not by Insulin. The Journal of Biological Chemistry. 1990;265(30):18051-4.
[239]. Sone H, Deo BK, Kumagai AK. Enhancement of Glucose Transport by Vascular
Endothelial Growth Factor in Retinal Endothelial Cells. Invest Ophthalmol Vis Sci.
2000;41(7):1876-84.
[240]. Senger DR, Galli, Stephen J., Dvorak, Ann M., Perruzzi, Carole A., Harvey, V.
Susan., Dvorak, Harold F. Tumor Cells Secrete a Vascular Permeability Factor that Promotes
Accumulation of Ascites Fluid. Science. 1983;219(4587):983-5.
[241]. Cobleigh MA, Langmuir VK, Sledge GW, Miller KD, Haney L, Novotny WF, et al.
A phase I/II dose-escalation trial of bevacizumab in previously treated metastatic breast
cancer. Seminars in Oncology. 2003;30(S16):117-24.
[242]. Ramaswamy B, Elias AD, Kelbick NT, Dodley A, Morrow M, Hauger M, et al. Phase
II Trial of Bevacizumab in Combination with Weekly Docetaxel in Metastatic Breast Cancer
Patients. Clinical Cancer Research. 2006;12(10):3124-9.
60
[243]. Yang JC, Haworth L, Sherry RM, Hwu P, Schwartzentruber DJ, Topalian SL, et al. A
Randomized Trial of Bevacizumab, an Anti-Vascular Endothelial Growth Factor Antibody,
for Metastatic Renal Cancer. N Engl J Med. 2003;349(5):427-34.
[244]. Kabbinavar F, Hurwitz HI, Fehrenbacher L, Meropol NJ, Novotny WF, Lieberman G,
et al. Phase II, Randomized Trial Comparing Bevacizumab Plus Fluorouracil
(FU)/Leucovorin (LV) With FU/LV Alone in Patients With Metastatic Colorectal Cancer. J
Clin Oncol. 2003;21(1):60-5.
[245]. Tol J, Koopman M, Rodenburg CJ, Cats A, Creemers GJ, Schrama JG, et al. A
randomised phase III study on capecitabine, oxaliplatin and bevacizumab with or without
cetuximab in first-line advanced colorectal cancer, the CAIRO2 study of the Dutch
Colorectal Cancer Group (DCCG). An interim analysis of toxicity. Annals of Oncology.
2008;19(4):734-8.
[246]. Escudier B, Pluzanska A, Koralewski P, Ravaud A, Bracarda S, Szczylik C, et al.
Bevacizumab plus interferon alfa-2a for treatment of metastatic renal cell carcinoma: a
randomised, double-blind phase III trial. The Lancet. 2007;370(9605):2103-11.
[247]. Giantonio BJ, Catalano PJ, Meropol NJ, O'Dwyer PJ, Mitchell EP, Alberts SR, et al.
Bevacizumab in Combination With Oxaliplatin, Fluorouracil, and Leucovorin (FOLFOX4)
for Previously Treated Metastatic Colorectal Cancer: Results From the Eastern Cooperative
Oncology Group Study E3200. J Clin Oncol. 2007;25(12):1539-44.
[248]. Hurwitz HI, Fehrenbacher L, Hainsworth JD, Heim W, Berlin J, Holmgren E, et al.
Bevacizumab in Combination With Fluorouracil and Leucovorin: An Active Regimen for
First-Line Metastatic Colorectal Cancer. J Clin Oncol. 2005;23(15):3502-8.
[249]. Duran I, Hotta SJ, Hirte H, Chen EX, MacLean M, Turner S, et al. Phase I Targeted
Combination Trial of Sorafenib and Erlotinib in Patients with Advanced Solid Tumors.
Clinical Cancer Research. 2007;13(16):4849-57.
[250]. Siu LL, Awada A, Takimoto CH, Piccart M, Schwartz B, Giannaris T, et al. Phase I
Trial of Sorafenib and Gemcitabine in Advanced Solid Tumors with an Expanded Cohort in
Advanced Pancreatic Cancer. Clinical Cancer Research. 2006;12(1):144-51.
[251]. Brose MS, Nellore A, Paziana K, Ransone K, Redlinger M, Flaherty KT, et al. A
phase II study of sorafenib in metastatic thyroid carcinoma. J Clin Oncol (Meeting
Abstracts). 2008;26(15):6026.
[252]. Dahut WL, Scripture C, Posadas E, Jain L, Gulley JL, Arlen PM, et al. A Phase II
Clinical Trial of Sorafenib in Androgen-Independent Prostate Cancer. Clinical Cancer
Research. 2008;14(1):209-14.
[253]. Steinbild S, Mross K, Frost A, Morant R, Gillessen S, Dittrich C, et al. A clinical
phase II study with sorafenib in patients with progressive hormone-refractory prostate cancer:
a study of the CESAR Central European Society for Anticancer Drug Research-EWIV. Br J
Cancer. 2007;97(11):1480-5.
[254]. Gupta-Abramson V, Troxel AB, Nellore A, Puttaswamy K, Redlinger M, Ransone K,
et al. Phase II Trial of Sorafenib in Advanced Thyroid Cancer. J Clin Oncol.
2008;26(29):4714-9.
[255]. Akaza H, Naito S, Tsukamoto T, Nakajima K, Murai M. Uncontrolled Confirmatory
Trial of Single-Agent Sorafenib in Japanese Patients with Advanced Renal Cell Carcinoma.
European Urology Supplements. 2007;6(2):237-.
[256]. Chi KN, Ellard SL, Hotte SJ, Czaykowski P, Moore M, Ruether JD, et al. A phase II
study of sorafenib in patients with chemo-naive castration-resistant prostate cancer. Annals of
Oncology. 2008;19(4):746-51.
61
[257]. Yau T, Chan P, Ng KK, Chok SH, Cheung TT, Fan ST, et al. Phase 2 open-label
study of single-agent sorafenib in treating advanced hepatocellular carcinoma in a hepatitis
B-endemic Asian population. Cancer. 2009;115(2):428-36.
[258]. Gollob JA, Rathmell WK, Richmond TM, Marino CB, Miller EK, Grigson G, et al.
Phase II Trial of Sorafenib Plus Interferon Alfa-2b As First- or Second-Line Therapy in
Patients With Metastatic Renal Cell Cancer. J Clin Oncol. 2007;25(22):3288-95.
[259]. Rini BI, Wilding G, Hudes G, Stadler WM, Kim S, Tarazi J, et al. Phase II Study of
Axitinib in Sorafenib-Refractory Metastatic Renal Cell Carcinoma. J Clin Oncol.
2009;27(27):4462-8.
[260]. Kane RC, Farrell AT, Saber H, Tang S, Williams G, Jee JM, et al. Sorafenib for the
Treatment of Advanced Renal Cell Carcinoma. Clinical Cancer Research. 2006;12(24):72718.
[261]. Feldman DR, Kondagunta GV, Ronnen EA, Fischer P, Chang R, Baum M, et al.
Phase I trial of bevacizumab plus sunitinib in patients (pts) with metastatic renal cell
carcinoma (mRCC). J Clin Oncol (Meeting Abstracts). 2007;25(18S):5099.
[262]. Saltz LB, Rosen LS, Marshall JL, Belt RJ, Hurwitz HI, Eckhardt SG, et al. Phase II
Trial of Sunitinib in Patients With Metastatic Colorectal Cancer After Failure of Standard
Therapy. J Clin Oncol. 2007;25(30):4793-9.
[263]. Socinski MA, Novello S, Brahmer JR, Rosell R, Sanchez JM, Belani CP, et al.
Multicenter, Phase II Trial of Sunitinib in Previously Treated, Advanced Non-Small-Cell
Lung Cancer. J Clin Oncol. 2008;26(4):650-6.
[264]. Burstein HJ, Elias AD, Rugo HS, Cobleigh MA, Wolff AC, Eisenberg PD, et al.
Phase II Study of Sunitinib Malate, an Oral Multitargeted Tyrosine Kinase Inhibitor, in
Patients With Metastatic Breast Cancer Previously Treated With an Anthracycline and a
Taxane. J Clin Oncol. 2008;26(11):1810-6.
[265]. Cohen EE, Needles BM, Cullen KJ, Wong SJ, Wade III JL, Ivy SP, et al. Phase 2
study of sunitinib in refractory thyroid cancer. J Clin Oncol (Meeting Abstracts). 2008 May
20, 2008;26(15_suppl):6025-.
[266]. Choong NW, Cohen EE, Kozloff MF, Taber D, Wade III JL, Hu S, et al. Phase II trial
of sunitinib in patients with recurrent and/or metastatic squamous cell carcinoma of the head
and neck (SCCHN). J Clin Oncol (Meeting Abstracts). 2008 May 20, 2008;26(15S):6064.
[267]. Motzer RJ, Hutson TE, Tomczak P, Michaelson MD, Bukowski RM, Rixe O, et al.
Sunitinib versus Interferon Alfa in Metastatic Renal-Cell Carcinoma. N Engl J Med.
2007;356(2):115-24.
[268]. Ryan C, Stadler W, Roth B, Hutcheon D, Conry S, Puchalski T, et al. Phase I dose
escalation and pharmacokinetic study of AZD2171, an inhibitor of the vascular endothelial
growth factor receptor tyrosine kinase, in patients with hormone refractory prostate cancer
(HRPC). Investigational New Drugs. 2007;25(5):445-51.
[269]. Drevs J, Siegert P, Medinger M, Mross K, Strecker R, Zirrgiebel U, et al. Phase I
Clinical Study of AZD2171, an Oral Vascular Endothelial Growth Factor Signaling Inhibitor,
in Patients With Advanced Solid Tumors. J Clin Oncol. 2007;25(21):3045-54.
[270]. Hirte HW, Vidal L, Fleming GF, Sugimoto AK, Morgan RJ, Biagi JJ, et al. A phase II
study of cediranib (AZD2171) in recurrent or persistent ovarian, peritoneal or fallopian tube
cancer: Final results of a PMH, Chicago and California consortia trial. J Clin Oncol (Meeting
Abstracts). 2008;26(15S):5521.
[271]. Sridhar SS, Hotte SJ, Mackenzie MJ, Kollmannsberger C, Haider MA, Pond GR, et
al. Phase II study of the angiogenesis inhibitor AZD2171 in first line, progressive,
62
unresectable, advanced metastatic renal cell carcinoma (RCC): A trial of the PMH Phase II
Consortium. J Clin Oncol (Meeting Abstracts). 2007;25(18S):5093.
[272]. Patnaik A, Pipas M, Rosen LS, Wood L, Phipps K, Mulay M, et al. A phase I dose
escalation and pharmacokinetic (PK) study of intravenous (iv) aflibercept (VEGF Trap) plus
weekly gemcitabine (Gem) in patients (pts) with advanced solid tumors: preliminary results. J
Clin Oncol (Meeting Abstracts). 2008;26(15S):3558.
[273]. SanofiAventis. Sanofi-aventis and Regeneron Announce Results from Phase 2 Study
with Aflibercept (VEGF Trap) in Advanced Ovarian Cancer with Recurrent Symptomatic
Malignant Ascites. 2009 [cited 2009 August 12]; Available from: http://en.sanofiaventis.com/binaries/20090611_vegf_trap_en_tcm28-25312.pdf.
[274]. Tang P, Cohen SJ, Bjarnason GA, Kollmannsberger C, Virik K, MacKenzie MJ, et al.
Phase II trial of aflibercept (VEGF Trap) in previously treated patients with metastatic
colorectal cancer (MCRC): A PMH phase II consortium trial. J Clin Oncol (Meeting
Abstracts). 2008;26(15S):4027.
[275]. Townsley C, Hirte H, Hoskins P, Buckanovich R, Mackay H, Welch S, et al. A phase
II study of aflibercept (VEGF trap) in recurrent or metastatic gynecologic soft-tissue
sarcomas: A study of the Princess Margaret Hospital Phase II Consortium. J Clin Oncol
(Meeting Abstracts). 2009;27(15S):5591.
[276]. Rugo HS, Herbst RS, Liu G, Park JW, Kies MS, Steinfeldt HM, et al. Phase I Trial of
the Oral Antiangiogenesis Agent AG-013736 in Patients With Advanced Solid Tumors:
Pharmacokinetic and Clinical Results. J Clin Oncol. 2005;23(24):5474-83.
[277]. Spano J, Moore M, Kim S, Liau KF, Hee B, Bycott P, et al. A phase I study of
axitinib (AG-013736), a potent inhibitor of VEGFRs, in combination with gemcitabine
(GEM) in patients (pts) with advanced pancreatic cancer. J Clin Oncol (Meeting Abstracts).
2006;24(18S):13092.
[278]. Giles FJ, Steinfeldt H, Bellamy WT, Bycott P, Pithavala Y, Reich SD, et al. Phase 2
Study of the Anti-Angiogenesis Agent AG-013736 in Patients with Poor Prognosis Acute
Myeloid Leukemia (AML) or Myelodysplastic Syndrome (MDS). ASH Annual Meeting
Abstracts. 2004;104(11):1813.
[279]. Schiller JH, Larson T, Ou SI, Limentani SA, Sandler AB, Vokes EE, et al. Efficacy
and safety of axitinib (AG-013736; AG) in patients (pts) with advanced non-small cell lung
cancer (NSCLC): A phase II trial. J Clin Oncol (Meeting Abstracts). 2007;25(18):7507.
[280]. Cohen EE, Vokes EE, Rosen LS, Kies MS, Forastiere AA, Worden FP, et al. A phase
II study of axitinib (AG-013736 [AG]) in patients (pts) with advanced thyroid cancers. J Clin
Oncol (Meeting Abstracts). 2007;25(18S):6008.
[281]. Rosen LS, Kurzrock R, Mulay M, Van Vugt A, Purdom M, Ng C, et al. Safety,
Pharmacokinetics, and Efficacy of AMG 706, an Oral Multikinase Inhibitor, in Patients With
Advanced Solid Tumors. J Clin Oncol. 2007;25(17):2369-76.
[282]. Sherman SI, Schlumberger MJ, Droz J, Hoffmann M, Wirth L, Bastholt L, et al.
Initial results from a phase II trial of motesanib diphosphate (AMG 706) in patients with
differentiated thyroid cancer (DTC). J Clin Oncol (Meeting Abstracts). 2007;25(18S):6017.
[283]. Holden SN, Eckhardt SG, Basser R, de Boer R, Rischin D, Green M, et al. Clinical
evaluation of ZD6474, an orally active inhibitor of VEGF and EGF receptor signaling, in
patients with solid, malignant tumors. Annals of Oncology. 2005;16(8):1391-7.
[284]. Miller KD, Trigo JM, Wheeler C, Barge A, Rowbottom J, Sledge G, et al. A
Multicenter Phase II Trial of ZD6474, a Vascular Endothelial Growth Factor Receptor-2 and
Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor, in Patients with Previously
Treated Metastatic Breast Cancer. Clinical Cancer Research. 2005;11(9):3369-76.
63
[285]. Wells S, You YN, Lakhani V, Hou J, Langmuir P, Headley D, et al. A phase II trial of
ZD6474 in patients with hereditary metastatic medullary thyroid cancer. J Clin Oncol
(Meeting Abstracts). 2006;24(18S):5533.
[286]. Joensuu H, De Braud F, Coco P, De Pas T, Putzu C, Spreafico C, et al. Phase II, openlabel study of PTK787/ZK222584 for the treatment of metastatic gastrointestinal stromal
tumors resistant to imatinib mesylate. Annals of Oncology. 2008;19(1):173-7.