Squamous-cell carcinoma
- new biomarkers
Rafal Dziadziuszko
Medical University of Gdańsk, Poland
Molecular aberrations
in lung adenocarcinoma
Driving molecular events:
- EGFR mutations
- HER2 mutations
- KRAS mutations
- BRAF mutations
- MEK mutations
- ALK rearrangement
- RET rearrangement
- ROS1 rearrangement
- MET amplification
- Others…
Markers related to progression:
- EGFR, MET high copy number
- High plasma ligand levels
(EGF, HGF, VEGF etc.)
- IL-6 paracrine circuit
- Markers of aquired resistance
(T790M, MET for EGFR inhib.)
- Markers of DNA repair capacity
- Markers of tumor angiogenesis
- Others…
Who is the driver?
• Molecular aberration fulfilling
the criteria of „oncogene addiction”
• Usually mutually exclusive with other drivers
(or almost mutually exclusive) and associated
with particular histology
• Cell line inhibition with nanomolar
concentrations of the target inhibitor;
high activity in animal models
Markers of progression
• Associated with tumor progression, not
initiation; usually quantitative rather than
qualitative
• Usually not mutually exclusive with other
molecular events
• Inhibition related to some theraputic benefit
in cell lines and in vivo models; often transient
and bypassed by other mechanisms
Lung adenocarcinoma:
molecular subtypes according to driver mutations
K-RAS
EGFR
ALK
MET
PDGFR
ROS
ERBB2
BRAF
PIK3CA
MEK1
Mutations in NSCLC cell lines. Sharma, et al. Nat Rev Cancer 2010
Lung Cancer Molecular Consortium
Analysis in clinical samples of lung adenocarcinomas
No Mutation
Detected
AKT1
NRAS
MEK1
MET AMP
HER2
PIK3CA 2%
BRAF 2%
Double
Mutants 3%
EML4-AKL
7%
KRAS
22%
EGFR
17%
• Mutations found in 54% (280/516) of tumors
completely tested (95% CI: 50% to 59%)
Kris MG, et al. ASCO 2011. CRA7506. Johnson BE, et al. IASLC WCLC 2011. Abstract O16.01
Squamous-cell carcinoma of the lung
~25% – 60% of all lung cancer diagnoses
(geographical variation)
Squamous-cell carcinoma of the lung:
The „new” drivers?
b
- EGFR vIII (del 2-7 EGFR) mutations
- FGFR1 amplification
- DDR2 mutations
- SOX2 amplification
- PIK3CA amplification
EGFR vIII (del 2-7 EGFR) mutations
• In-frame deletion of exons 2 – 7 identified
in a significant proportion of glioblastomas
• Demonstrated in 3/56 (5%, Ji et al.) and 7/87
(8%, Sasaki et al.) of SCCs at genomic level
• Immunohistochemical staining against EGFRvIII
protein is possible but good correlative studies
are lacking
Ji H et al., PNAS 103:7817 – 22, 2006; Sasaki H et al., Oncol Rep 17: 319-23, 2007
EGFR vIII (del 2-7 EGFR) mutations
Tet-op-EGFR vIII Bi-Transgenic animals develop AAH and
invasive adenocarcinomas after 8 and 16 weeks of doxycycline
administration, respectively
Ji H et al., PNAS 103:7817 – 22, 2006
EGFR vIII (del 2-7 EGFR) mutations
EGFR vIII transformed Ba/F3 cells are sensitive to EGFR inhibition
with irreversible HKI-272 and less sensitive to erlotinib
Ji H et al., PNAS 103:7817 – 22, 2006
EGFR vIII (del 2-7 EGFR) mutations
EGFR vIII tumors had higher EGFR gene copy number
as compared to EGFR WT tumors (mean 4.7 vs. 2.2 copies by qPCR)
Sasaki H et al., Oncol Rep 17: 319-23, 2007
EGFR vIII (del 2-7 EGFR) mutations
Conclusions
• Detection difficult due to need for relatively
complex assays on genomic level
• Clinical significance and true prevalence
unknown
• More preclinical and clinical data needed
EGFR vIII (del 2-7 EGFR) mutations
MLPA assay
Assay developed by Prof. Piotr Kozlowski, Polish Academy of Science, Poznan
FGFR1 amplification
•
•
Detected in 34/153 SCCs (22%) by FISH (defined as mean>4
copies per nucleus)
Associated with sensitivity to FGFR1 inhibitor PD173074 in cell
lines and animal models
Weiss J et al., Sci Transl Med. 2: 62ra93, 2010
FGFR1 amplification
Dutt A. et al., PLoS ONE. 6: e20351, 2011
FGFR1 amplification
Weiss J et al., Sci Transl Med. 2: 62ra93, 2010
FGFR1 amplification
Polish NSCLC cohort analyzed by SISH, N=59
Squamous
FGFR1 2.08
CH 8 2.16
Ratio 0.96
Squamous
FGFR1 4.78
CH 8 4.32
Ratio 1.11
16% of SCCs amplified
Wynes MW et al., poster presentation; Chicago 2011
FGFR1 amplification
Conclusions
• Observed in ~ 20% of SCCs
• Optimal cut-off point to define amplification?
• Attractive target currently evaluated in clinical
trials
Discoidin domain receptor 2 (DDR2) mutations
Observed across entire DDR2 gene, in ~ 4% of SCCs
Hammerman PS et al., Cancer Discovery. 1:78-89, 2011
DDR2 mutations
DDR2 mutated cell lines are sensitive to src inhibitor dasatinib
Hammerman PS et al., Cancer Discovery. 1:78-89, 2011
DDR2 mutations
DDR2 mutated cell lines are sensitive to src inhibitor dasatinib
Hammerman PS et al., Cancer Discovery. 1:78-89, 2011
SOX2
• Transcription factor involved in foregut
development and squamous differentiation
of epithelial esophagal and respiratory cells
• Located at 3q26 amplicon observed
in ~ 20 – 30% of SCCs
• Major regulator of stem-cell function and
the cell cycle; suppression leads to
antiproliferative effect in cell lines
Hussenet et al. PLoS ONE 2010
Bass et al. Nat Genet 2009
PI3KCA
• Catalytic subunit alpha of phosphatidylinositol
3-kinase
• Mutations observed in ~2-3% of SCCs,
amplification in ~ 30% of SCCs (3q26 amplicon
containing SOX2)
• Several therapeutics are currently
in phase I – phase II clinical trials
Squamous-cell carcinoma:
molecular subtypes
Perez-Moreno P et al. CCR 2012 in press
Squamous-cell
carcinoma:
getting hot
and spicy