MP65-04 LONG NON-CODING RNA GAS5 MODULATES GEMCITABINE EFFICACY IN BLADDER CANCER VIA REGULATION OF DEOXYCYTIDINE KINASE EXPRESSION

Abstract

You have accessJournal of UrologyBladder Cancer: Basic Research & Pathophysiology III1 Apr 2018MP65-04 LONG NON-CODING RNA GAS5 MODULATES GEMCITABINE EFFICACY IN BLADDER CANCER VIA REGULATION OF DEOXYCYTIDINE KINASE EXPRESSION Wei Chen, Junlong Zhuang, Wenmin Cao, Wenli Diao, and Hongqian Guo Wei ChenWei Chen More articles by this author , Junlong ZhuangJunlong Zhuang More articles by this author , Wenmin CaoWenmin Cao More articles by this author , Wenli DiaoWenli Diao More articles by this author , and Hongqian GuoHongqian Guo More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2018.02.2070AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Gemcitabine is a common used agent for therapy in bladder cancer. Our objective was to characterize the ability of Long non-coding RNA GAS5 to modulate the gemcitabine efficacy. METHODS Expression of GAS5 was analyzed using real-time quantitative polymerase chain reaction (RT-qPCR) in 30 patients following radical cystectomy and gemcitabine treatment. All subjects signed written informed consent. The study was approved by the Hospital Ethics Boards prior to initiation. The correlation between GAS5 and deoxycytidine kinase (DCK) was further examined by evaluating DCK expression in cells that either overexpressed or knocked down GAS5. Gemcitabine efficacy was identified by CCK-8 assays. DCK and HuR were analyzed by western blotting and immunofluorescence. RESULTS GAS5 was significantly downregulated in bladder cancer tissues compared with the paired adjacent non-tumorous tissues. Lower GAS5 expression levels were associated with advanced pathological stages and poor overall survival (Fig. 1). LncRNA GAS5 expression is also lower in T24, 5637 and SW780 compared with the human normal urothelial cell line (Sv-Huc-1). GAS5 level was well correlated with the sensitivity of the cancer cells toward gemcitabine. Gemcitabine can dose-dependently increase GAS5 level in bladder cancer cells. Of note, pretreated gemcitabine attenuated GAS5-induced with a second dose of gemcitabine. GAS5-overexpressing cells displayed an elevated level of cell death induced by gemcitabine. Accordingly, knockdown of GAS5 in bladder cancer cells by small interfering RNA conferred tolerance to gemcitabine-induced cytotoxicity (Figure 3C, 3D). DCK is the rate-limiting enzyme responsible for conversion of gemcitabine to active antimetabolite. By knocking down GAS5 in bladder cancer cells, we experimentally confirmed that GAS5 regulates DCK expression. Furthermore, we revealed that proapoptotic function of GAS5 was correlated with promoting HuR nuclear export and the biological consequence of deoxycytidine kinase expression (Fig. 2). CONCLUSIONS This study shows that long non-coding RNA GAS5 modulates HuR-mediated DCK expression, and GAS5 low expression confers gemcitabine tolerance. The expression of GAS5 may represent a novel companion diagnostic and target to undermine chemotherapy resistance. © 2018FiguresReferencesRelatedDetails Volume 199Issue 4SApril 2018Page: e859-e860 Advertisement Copyright & Permissions© 2018MetricsAuthor Information Wei Chen More articles by this author Junlong Zhuang More articles by this author Wenmin Cao More articles by this author Wenli Diao More articles by this author Hongqian Guo More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...