TY - JOUR
T1 - Activation of EIF4E by Aurora kinase A depicts a novel druggable axis in everolimus-resistant cancer cells
AU - Katsha, Ahmed
AU - Wang, Lihong
AU - Arras, Janet
AU - Omar, Omar M.
AU - Ecsedy, Jeffrey
AU - Belkhiri, Abbes
AU - El-Rifai, Wael
N1 - Funding Information:
This study was supported by a Research Career Scientist award (1IK6BX003787) from the U.S. Department of Veterans Affairs (to W. El-Rifai) and grants from the NIH (R01CA131225 and R01CA93999; to W. El-Rifai). This study was also supported by NIH grants that include Vanderbilt SPORE in Gastrointestinal Cancer (P50 CA95103), Vanderbilt Ingram Cancer Center (P30 CA68485), and the Vanderbilt Digestive Disease Research Center (DK058404). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
Publisher Copyright:
©2017 AACR.
PY - 2017/7/15
Y1 - 2017/7/15
N2 - Purpose: Aurora kinase A (AURKA) is overexpressed in several cancer types, making it an attractive druggable target in clinical trials. In this study, we investigated the role of AURKA in regulating EIF4E, cap-dependent translation, and resistance to mTOR inhibitor, RAD001 (everolimus). Experimental Design: Tumor xenografts and in vitro cell models of upper gastrointestinal adenocarcinomas (UGC) were used to determine the role of AURKA in the activation of EIF4E and cap-dependent translation. Overexpression, knockdown, and phar-macologic inhibition of AURKA were used in vitro and in vivo. Results: Using in vitro cell models, we found that high protein levels of AURKA mediate phosphorylation of EIF4E and upregulation of c-MYC. Notably, we detected overexpression of endogenous AURKA in everolimus-resistant UGC cell models. AURKA mediated phosphorylation of EIF4E, activation of cap-dependent translation, and an increase in c-MYC protein levels. Targeting AURKA using genetic knockdown or a small-molecule inhibitor, alisertib, reversed these molecular events, leading to a decrease in cancer cell survival in acquired and intrinsic resistant cell models. Mechanistic studies demonstrated that AURKA binds to and inactivates protein phosphatase 2A, a negative regulator of EIF4E, leading to phosphorylation and activation of EIF4E in an AKT-, ERK1/2-, and mTOR-independent manner. Data from tumor xenograft mouse models confirmed that everolimus-resistant cancer cells are sensitive to alisertib. Conclusions: Our results indicate that AURKA plays an important role in the activation of EIF4E and cap-dependent translation. Targeting the AURKA–EIF4E–c-MYC axis using alisertib is a novel therapeutic strategy that can be applicable for everolimus-resistant tumors and/or subgroups of cancers that show overexpression of AURKA and activation of EIF4E and c-MYC.
AB - Purpose: Aurora kinase A (AURKA) is overexpressed in several cancer types, making it an attractive druggable target in clinical trials. In this study, we investigated the role of AURKA in regulating EIF4E, cap-dependent translation, and resistance to mTOR inhibitor, RAD001 (everolimus). Experimental Design: Tumor xenografts and in vitro cell models of upper gastrointestinal adenocarcinomas (UGC) were used to determine the role of AURKA in the activation of EIF4E and cap-dependent translation. Overexpression, knockdown, and phar-macologic inhibition of AURKA were used in vitro and in vivo. Results: Using in vitro cell models, we found that high protein levels of AURKA mediate phosphorylation of EIF4E and upregulation of c-MYC. Notably, we detected overexpression of endogenous AURKA in everolimus-resistant UGC cell models. AURKA mediated phosphorylation of EIF4E, activation of cap-dependent translation, and an increase in c-MYC protein levels. Targeting AURKA using genetic knockdown or a small-molecule inhibitor, alisertib, reversed these molecular events, leading to a decrease in cancer cell survival in acquired and intrinsic resistant cell models. Mechanistic studies demonstrated that AURKA binds to and inactivates protein phosphatase 2A, a negative regulator of EIF4E, leading to phosphorylation and activation of EIF4E in an AKT-, ERK1/2-, and mTOR-independent manner. Data from tumor xenograft mouse models confirmed that everolimus-resistant cancer cells are sensitive to alisertib. Conclusions: Our results indicate that AURKA plays an important role in the activation of EIF4E and cap-dependent translation. Targeting the AURKA–EIF4E–c-MYC axis using alisertib is a novel therapeutic strategy that can be applicable for everolimus-resistant tumors and/or subgroups of cancers that show overexpression of AURKA and activation of EIF4E and c-MYC.
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U2 - 10.1158/1078-0432.CCR-16-2141
DO - 10.1158/1078-0432.CCR-16-2141
M3 - Article
C2 - 28073841
AN - SCOPUS:85024089179
VL - 23
SP - 3756
EP - 3768
JO - Clinical Cancer Research
JF - Clinical Cancer Research
SN - 1078-0432
IS - 14
ER -