Genetic and pharmacologic inhibition of EPHA2 promotes apoptosis in NSCLC
Katherine R. Amato, Shan Wang, Andrew K. Hastings, Victoria M. Youngblood, Pranav R. Santapuram, Haiying Chen, Justin M. Cates, Daniel C. Colvin, Fei Ye, Dana M. Brantley-Sieders, Rebecca S. Cook, Li Tan, Nathanael S. Gray, Jin Chen
Katherine R. Amato, Shan Wang, Andrew K. Hastings, Victoria M. Youngblood, Pranav R. Santapuram, Haiying Chen, Justin M. Cates, Daniel C. Colvin, Fei Ye, Dana M. Brantley-Sieders, Rebecca S. Cook, Li Tan, Nathanael S. Gray, Jin Chen
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Research Article Oncology

Genetic and pharmacologic inhibition of EPHA2 promotes apoptosis in NSCLC

Abstract

Genome-wide analyses determined previously that the receptor tyrosine kinase (RTK) EPHA2 is commonly overexpressed in non–small cell lung cancers (NSCLCs). EPHA2 overexpression is associated with poor clinical outcomes; therefore, EPHA2 may represent a promising therapeutic target for patients with NSCLC. In support of this hypothesis, here we have shown that targeted disruption of EphA2 in a murine model of aggressive Kras-mutant NSCLC impairs tumor growth. Knockdown of EPHA2 in human NSCLC cell lines reduced cell growth and viability, confirming the epithelial cell autonomous requirements for EPHA2 in NSCLCs. Targeting EPHA2 in NSCLCs decreased S6K1-mediated phosphorylation of cell death agonist BAD and induced apoptosis. Induction of EPHA2 knockdown within established NSCLC tumors in a subcutaneous murine model reduced tumor volume and induced tumor cell death. Furthermore, an ATP-competitive EPHA2 RTK inhibitor, ALW-II-41-27, reduced the number of viable NSCLC cells in a time-dependent and dose-dependent manner in vitro and induced tumor regression in human NSCLC xenografts in vivo. Collectively, these data demonstrate a role for EPHA2 in the maintenance and progression of NSCLCs and provide evidence that ALW-II-41-27 effectively inhibits EPHA2-mediated tumor growth in preclinical models of NSCLC.

Authors

Katherine R. Amato, Shan Wang, Andrew K. Hastings, Victoria M. Youngblood, Pranav R. Santapuram, Haiying Chen, Justin M. Cates, Daniel C. Colvin, Fei Ye, Dana M. Brantley-Sieders, Rebecca S. Cook, Li Tan, Nathanael S. Gray, Jin Chen

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Figure 7

ALW-II-41-27 treatment leads to decreased cell viability in NSCLC cell lines.

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ALW-II-41-27 treatment leads to decreased cell viability in NSCLC cell l...
(A) NSCLC cell lines were treated with ALW-II-41-27, NG-25, or DMSO for 72 hours, and cell viability was assessed by the MTT assay. Shown are percentages of cell viability ± SEM in drug treatment groups relative to a DMSO control group. (B) H2009 and H358 cells were treated with 1 μM ALW-II-41-27 or DMSO for 6 hours. Cells were starved 24 hours and stimulated with 10% serum-containing media 10 minutes before lysis. EPHA2 was pulled down in immunoprecipitation and immunoblotted for pY99 and pY20 (represented here as p-EPHA2 [pY]). Phosphorylation of other signaling molecules was determined by Western blot analyses using anti-phospho or anti-total protein antibodies as indicated. Shown are blots representative of 2 to 3 independent experiments for each signaling molecule.