The MET oncogene:
From molecular biology to Clinical Trials
Paolo M. Comoglio, MD
Institute for Cancer Research @ Candiolo,
University of Turin, Medical School, Italy
MET IS A ‘MASTER GENE’
IN THE CONTROL OF INVASIVE GROWTH
HGF (Scatter Factor)
Sema domain
500 AA
MRS
(PSI)
G-P rich
Ig like domains
400 AA
Kringles
Proteaselike
P
P
Tyrosine Kinase
P
P
Met
(HGF Receptor)
Plexin B1
MET
Integrin 6 4
CD44v6
Link to cytoskeleton
PI3K
RAS
P
P
p85 P
P
GRB2
STAT
Transient MAP kinase
activation (proliferation)
p85
PI3K
CRKL
GAB1
P
SHP2
GRB2P
PLC
SRC
Cell-Polarity and
Morphogenesis
C.Boccaccio and PM.Comoglio. Nature Rev. Cancer.
2006, 6: 637-645.
Sustained MAP and PI3 kinase
activation (invasion / apoptosis
protection)
MET IS A FUNCTIONAL MARKER OF
CANCER STEM CELLS
Human metastatic
colorectal cancer
Xenopatient
Spheropatient
Xenosphere
(cancer stem cells)
Xenopatients, Xenospheres and Spheropatients
Xenopatient
Xenosphere
(cancer stem cells)
Spheropatient
(Secondary xenopatient)
Mutations retained and passed on
Response to targeted drugs retained and passed on
C. Boccaccio et al., in preparation
MET inhibition
promotes differentiation of CRC colospheres
Control
JNJ inhib.
Cetuximab
Fibroblast conditioned medium
0% serum
ACTIVATION OF THE
MET-DRIVEN ‘INVASIVE GROWTH’ PROGRAMME
GENERATES AN AGGRESSIVE PHENOTYPE
• ONCOGENE ‘EXPEDIENCE’
• ONCOGENE ‘ADDICTION’
THE CONCEPT OF ‘ONCOGENE EXPEDIENCE ‘
• Met can promote invasion and metastasis independent of the
genetic lesions that caused tumour onset
• Met activation is a ‘stress’ response to unfavourable
microenvironment (hypoxia, radiations , inflammatory cytokines)
• Met activation occurs mainly through transcriptional
upregulation
• Met activation is an expedience that provides a pro-survival and
invasive advantage
Trusolino and Comoglio., Nature Rev. Drug Discov, 2008
Nature Rev. Mol. Cell. Biol. 2010
Hypoxia promotes invasive growth
by transcriptional activation of the MET Oncogene
Cellular [O2]
Proteasome
degradation
HIF Proline Hydroxylase
pVHL
Cytoplasm
HIF-1
(regulated)

 -OH
Nucleus
HIF-1
HIF-1

(constitutive)
P (-2619)
S (-411) S (-345) A (-253)
HRE-1
HRE-2
S (-295)
A (-32) START
S (+89)
AP-1
asHRE-1asHRE-2/
HRE-3
The MET promoter
HRE-4
A (+353)
HRE-5
CoCl2
MET
3% O2
21% O2
Control
Hypoxia promotes invasive growth
by transcriptional activation of the MET Oncogene
met mRNA
HIF-1a
28S
Pennacchietti, Michieli et al. , Cancer Cell 3: 347 (2003)
THE CONCEPT OF ‘ONCOGENE ADDICTION ‘
• In a limited number of cancer types, genetic lesions of Met are
selected along the tumour natural history to become the driving
force that maintains the transformed phenotype
• Met activation is the consequence of a fixed and transmissible
genetic alteration; therefore, it is characterized by chronic firing
and high steady-state signalling
‘Oncogenic addiction’ to MET in tumours
can be achieved by:
• Amplification
(e.g. gastric ca, NSCLCs and CRC mts resistant to targeted therapy)
• Point mutations
- hereditary and sporadic carcinomas (e.g. kidney, hepatocellular, head
& neck ca.
- early metastatic cancers of unknown primary origin (CUPs)
Trusolino and Comoglio, Nature Rev. Drug Discov. 2008
TARGET THERAPIES AGAINST MET
• An adjuvant approach for a vast number of tumours:
Overexpression: targeting ‘expedience’
(almost all solid tumors expressing MET)
- Endpoints: PFS, OS
• A front-line intervention for a limited fraction of
genotype-specific tumours:
Amplification, mutations : targeting ‘addiction’
(e.g. gastric ca., NSCLC, gefitinib-resistant NSCLCs)
- Endpoints: Remission
THERAPEUTIC INACTIVATION OF THE MET ONCOGENE
CAN BE ACHIEVED BY:
1.
Small molecules inhibiting the Tyrosine Kinase
2.
Monoclonal Antibodies
RESPONSE TO MET INHIBITORS
CORRELATES WITH GENE AMPLIFICATION
200 cancer l. tested
<3%
ADDICTION
97 %
EXPEDIENCE
Cell Line
MET
copy N°
EBC-1
5.8
MKN-45
6
GTL-16
6.1
HS746T
6.3
SNU5
5.6
NCIH1993
5.2
Hypoxia
(or HGF)
PHA-665752
PHA-665752
Clinical trials for MET inhibitors
• Inhibition of growth (reduction of tumor mass) is
expected only in cancers “addicted” to MET
• Genetic lesions are expected in ~ 3-4 % of epithelial
cancers
• It is mandatory to identify patiens with cancers
“addicted” to MET before recruitment
111In
DTPA-DN30 tumor uptake at 2h post injection
SPEC-CT scan
A2780
EBC1
Bardelli. et al. Cancer Discovery 2013
Detection of MET-amplification
by Liquid Biopsy
cell viability %
Xenopatient-derived cancer cells display MET amplification
and are sensitive to Met targeted drugs
1,4
1,2
1
0,8
0,6
0,4
0,2
0
NT
10
50
JNJ
500
10
50
500
CRIZOTINIB
Therapy with MET antibody
MV-DN30 Monoclonal Antibody
Monovalent, Chimeric, Stabilized
O
OH
n
•
•
•
•
Recombinant, properly assembled and PEGylated
Bind Met (IP4) with high affinity (Kd= 0,116 nM)
Down-regulate the Met receptor from the cell surface
Induce shedding of the extracellular domain (“decoy”)
Ligand
neutralization
Inactive
receptor
heterodimer
p125
Decoy
Inhibitory
effects
Shedding
Adam 10
Γ- secretase
Proteasome
degradation
Met
p175
p55
p50
Exogenous administration of anti-MET DN-30
inhibits tumor growth and prevent metastasis
Human Breast Carcinoma, transplanted in Athymic nu/nu mice
Irrelevant Mab
Mab DN30
Petrelli, A. et al., Proc. Natl.Acad Sci. US: 2006, 28, 5090-5095
CHEMOTHERAPY (CDDP, 5FU) vs MET ANTIBODY
TREATMENT OF EBC1
- Xenotransplants2200
NT
CDDP
2000
5FU
MV DN30
CDDP + MVDN30
1800
5FU + MVDN30
1400
Tumor volume (mm3)
Tumor Volume
.
1600
1200
1000
800
600
400
200
0
0
2
4
6
8
10
12
14
16
18
Days after injection
Days after injection
20
22
24
26
28
MECHANISMS OF ACQUIRED RESISTANCE
TO MET KINASE INHIBITORS
•
MET amplification
•
Activating point mutations
Amplification of MET contributes to
acquired resistance to MET kinase inhibitors
Wt
PHA resistant (150 nM)
Chromosome 7 centromere
GTL16
MET amplicon
marker
wt
Some MET mutations confer resistance
to MET inhibitors
PHA 250 nM
M1131T
V1188L
L1196V
V1220I
P S985
P Y1003
P
P
D1228H (Kit)
D1228N (Kit)
Y1230C
Y1230H
M250T (Ret)
a-pMet
a-Met
P Y1349
P Y1356
FAb DN30 treatment overcomes resistance
to the MET kinase Inhibitor PHA-665752
Viability in 50 nM PHA
DN30 Fab 0.4 mM
EBC1 wt
EBC1
Wild Type
EBC1 PHA Resistant
EBC1
PHA Resistant
MET and Invasive Growth:
State of the art:
1.
Scatter factors and the receptors of the MET oncogene family
(RON, ROR) are key regulators of the Invasive Growth program in
cancer stem cells.
2.
The program is activated by MET over expression, induced by
unfavourable micro-environmental conditions, such as hypoxia or
ionizing radiations: (“Oncogene Expedience”).
3.
The invasive growth program is constitutively activated in some
cancers, by MET amplification, mutations or autocrine loops
(“Oncogene Addiction”).
4.
The invasive growth program driven by the oncogene MET is a good
target for therapy.
5.
Resistance may occur, that may be overcome by combined
treatment with s.m. inhibitors and antibodies
IRCC
Experimental Clinical Molecular Oncology
Met and resistance
S. Giordano
S. Corso
A. Petrelli
C. Migliore
Met & Stem cells
C. Boccaccio
F. De Bacco
P. Luraghi
G. Reato
Ron & ROR
S. Benvenuti
A. Gentile
L. Lazzari
A. Arnesano
Met & Hypoxia
P. Michieli
S. Pennacchietti
C. Basilico
Met Addiction
L.Trusolino
A. Bertotti
F. Galimi
Met Gene Therapy
E. Vigna
S. Cignetto
R. Albano
Met Signature
E. Medico
Met Biology
L. Lanzetti
Met Genetics
A. Bardelli
M.F. Di Renzo
Plexins
L.Tamagnone
E. Giraudo
G. Serini
“Today Science, Tomorrow Medicine”
IRCC: Institute for Cancer Research
@ Candiolo