MP88-03 POTENTIAL ROLE OF G1P3 IN DEVELOPMENT OF CHEMORESISTANCE IN HIGH GRADE BLADDER CANCER

Abstract

You have accessJournal of UrologyBladder Cancer: Basic Research & Pathophysiology V1 Apr 2016MP88-03 POTENTIAL ROLE OF G1P3 IN DEVELOPMENT OF CHEMORESISTANCE IN HIGH GRADE BLADDER CANCER Syed Alam, Dharamainder Choudhary, Garrett Dancik, Carol Pilbeam, and John Taylor Syed AlamSyed Alam More articles by this author , Dharamainder ChoudharyDharamainder Choudhary More articles by this author , Garrett DancikGarrett Dancik More articles by this author , Carol PilbeamCarol Pilbeam More articles by this author , and John TaylorJohn Taylor More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.2421AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES G1P3 is a mitochondrial-membrane protein induced by Type I interferons. It has been shown to have anti-apoptotic properties in several cancers through suppression of cytochrome C release and inhibition of caspase function. G1P3 was found to be differentially overexpressed 15-fold in high grade cisplatin-resistant compared to cisplatin-sensitive patient tumors profiled by laser capture microdissection-coupled microarray. We sought to explore the role of G1P3 in bladder cancer cell lines and to determine its potential as a novel marker of cisplatin-resistance. METHODS Online microarray databases were used to assess expression levels in other bladder cancer datasets. Bladder cancer cell lines (HTB4, HTB5, HTB9, UMUC3) were cultured in defined media. Total RNA was extracted and qPCR performed. Transient transfections with G1P3 gene-specific siRNAs were performed. Cell cycle and apoptosis analyses were performed using flow cytometry and cell viability assays were performed via XTT. Clonogenic assays were performed using a crystal violet dye. RESULTS The microarray datasets in the Oncomine database revealed 3-8 fold increase in G1P3 expression in invasive vs. superficial bladder cancer. Prognostic analysis using the Bladder Cancer Biomarker Evaluation Tool (BC-BET) showed a hazard ratio of >2.80 for survival of patients in the top 50% of G1P3 expression versus the bottom 50%. G1P3 mRNA expression was detected in UMUC3, HTB4, and HTB9. Expression increased 1.7-fold in HTB9 and 1.6-fold in UMUC3 following cisplatin treatment. Knockdown of G1P3 expression by siRNA transfection in UMUC3 and HTB9 cells resulted in a 4.2% and 15% increase in total apoptotic cells following cisplatin (3 µM) treatment for 48 h. Cell cycle analysis of cisplatin treated UMUC3 and HTB9 cells revealed increased numbers of growth arrested S-phase cells - 4.9% and 28.4%, respectively. However, G1P3 knockdown did not significantly alter cisplatin-induced cell cycle changes. Further, compared to mock transfected UMUC3 cells, G1P3 knockdown resulted in decreased cell viability, and it prevented HTB9 colony growth. CONCLUSIONS G1P3 may play a role in cisplatin-resistance and proliferation in bladder cancer cells through suppression of apoptotic pathways. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e1129-e1130 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Syed Alam More articles by this author Dharamainder Choudhary More articles by this author Garrett Dancik More articles by this author Carol Pilbeam More articles by this author John Taylor More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...