586 CONTRIBUTORS TO HMGB1 RELEASE BY UROTHELIAL CARCINOMA CELLS IN RESPONSE TO BCG

Abstract

You have accessJournal of UrologyBladder Cancer: Basic Research (I)1 Apr 2013586 CONTRIBUTORS TO HMGB1 RELEASE BY UROTHELIAL CARCINOMA CELLS IN RESPONSE TO BCG Guangjian Zhang, Fanghong Chen, Yanli Cao, Gopit Shah, and William See Guangjian ZhangGuangjian Zhang Milwaukee, WI More articles by this author , Fanghong ChenFanghong Chen Milwaukee, WI More articles by this author , Yanli CaoYanli Cao Milwaukee, WI More articles by this author , Gopit ShahGopit Shah Milwaukee, WI More articles by this author , and William SeeWilliam See Milwaukee, WI More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.02.1982AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Recent work by our group has demonstrated that the powerful chemokine and marker of non-apoptotic cell death, high molecular group box 1 (HMGB1), is released by a portion of urothelial carcinoma (UC) tumor cells following BCG exposure. Elevated levels of HMGB1 have been observed in the urine of patients following intravesical BCG therapy. Most importantly, in vivo in models have demonstrated that tumor cells engineered to have reduced HMGB1 release fail to respond to intravesical BCG administration. Given the apparent importance of HMGB1 release for in vivo anti-tumor activity, this study evaluated the role of specific elements of BCG/tumor cell interaction in contributing to maximal HMGB1 release. METHODS Two human UC cell lines, T24 and 253J, were employed. HMGB1 concentrations in cell culture supernatant, with and without BCG treatment, served as the principal end point to assess the role of potentially involved variables. Specific techniques were utilized to determine the role of α5β1 antigen receptor crosslinking, BCG adherence, BCG internalization, BCG viability, iNOS expression/NO production, and p21 expression in mediating HMGB1 release by UC cells in response to BCG. RESULTS Crosslinking of α5β1 integrin was insufficient to induce HMGB1 release. HMGB1 release by crosslinked cells was not significantly different than untreated controls (p > 0.5). Treatment of cells with the peptide GRDGS to block α5β1 integrin and inhibit BCG adherence significantly inhibited HMGB1 release (p<0.001). Inhibition of BCG internalization by pretreatment of cells with Cytochalasin B significantly decreased HMGB1 release relative to BCG alone (p < 0.0001). Both viable and heat killed BCG significantly increased HMGB1 release by UC cells relative to controls (p < 0.01) The use of heat killed BCG significantly reduced HMGB1 release to 50% of values observed in response to viable BCG (p<0.0001). HMGB1 release by iNOS inhibited cells was significantly reduced (p < 0.01). Inducible knockdown of p21 expression in response to BCG significantly reduced HMGB1 release following BCG treatment (p < 0.01). CONCLUSIONS BCG induced non-apoptotic cell death and HMGB1 release occurs as a consequence of a complex multi-step process. Optimal HMGB1 release requires the adherence and internalization of viable BCG, iNOS activity, and p21 expression. An understanding of the steps and mechanisms involved in BCG induced HMGB1 release affords an opportunity for targeted strategies to improve BCG treatment efficacy. © 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 189Issue 4SApril 2013Page: e239-e240 Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.MetricsAuthor Information Guangjian Zhang Milwaukee, WI More articles by this author Fanghong Chen Milwaukee, WI More articles by this author Yanli Cao Milwaukee, WI More articles by this author Gopit Shah Milwaukee, WI More articles by this author William See Milwaukee, WI More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...