A receptor tyrosine kinase network composed of fibroblast growth factor receptors, epidermal growth factor receptor, v-erb-b2 erythroblastic leukemia viral oncogene homolog 2, and hepatocyte growth factor receptor drives growth and survival of head and neck squamous carcinoma cell lines.
Our laboratory has previously shown that some gefitinib-insensitive head and neck squamous cell carcinoma (HNSCC) cell lines exhibit dominant autocrine fibroblast growth factor receptor (FGFR) signaling. Herein, we deployed a whole-genome loss-of-function screen to identify genes whose knockdown potentiated the inhibitory effect of the FGFR inhibitor, AZ8010, in HNSCC cell lines. Three HNSCC cell lines expressing a genome-wide small hairpin RNA (shRNA) library were treated with AZ8010 and the abundance of shRNA sequences was assessed by deep sequencing. Under-represented shRNAs in treated cells are expected to target genes important for survival with AZ8010 treatment. Synthetic lethal hits were validated with specific inhibitors and independent shRNAs. We found that multiple alternate receptors provided protection from FGFR inhibition, including receptor tyrosine kinases (RTKs), v-erb-b2 erythroblastic leukemia viral oncogene homolog 2 (ERBB2), and hepatocyte growth factor receptor (MET). We showed that specific knockdown of either ERBB2 or MET in combination with FGFR inhibition led to increased inhibition of growth relative to FGFR tyrosine kinase inhibitor (TKI) treatment alone. These results were confirmed using specific small molecule inhibitors of either ERBB family members or MET. Moreover, the triple combination of FGFR, MET, and ERBB family inhibitors showed the largest inhibition of growth and induction of apoptosis compared with the double combinations. These results reveal a role for alternate RTKs in maintaining progrowth and survival signaling in HNSCC cells in the setting of FGFR inhibition. Thus, improved therapies for HNSCC patients could involve rationally designed combinations of TKIs targeting FGFR, ERBB family members, and MET.
Department of Craniofacial Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA. katherine.singleton@ucdenver.edu
Katherine R
KR
Singleton
Jihye
J
Kim
Trista K
TK
Hinz
Lindsay A
LA
Marek
Matias
M
Casás-Selves
Clark
C
Hatheway
Aik Choon
AC
Tan
James
J
DeGregori
Lynn E
LE
Heasley
D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D066246:ErbB Receptors / Q000037:antagonists & inhibitors / Q000502:physiology*; D053263:Gene Regulatory Networks / Q000187:drug effects / Q000502:physiology; D006258:Head and Neck Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D018739:Oncogene Proteins v-erbB / Q000037:antagonists & inhibitors / Q000502:physiology*; D019859:Proto-Oncogene Proteins c-met / Q000037:antagonists & inhibitors / Q000502:physiology*; D011799:Quinazolines / Q000494:pharmacology / Q000627:therapeutic use; D020794:Receptor Protein-Tyrosine Kinases / Q000502:physiology; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000502:physiology*; D017468:Receptors, Fibroblast Growth Factor / Q000037:antagonists & inhibitors / Q000502:physiology*
D066246:ErbB Receptors; D018739:Oncogene Proteins v-erbB; D019859:Proto-Oncogene Proteins c-met; D011799:Quinazolines; D020794:Receptor Protein-Tyrosine Kinases; D018719:Erb-b2 Receptor Tyrosine Kinases; D017468:Receptors, Fibroblast Growth Factor; C548875:AZD 8931; C508053:ERBB2 protein, human