MP49-06 STAT3 ACTIVATION STATUS CONTRIBUTES TO THE DIFFERENTIAL RESPONSES OF METASTATIC AND NO-METASTATIC HUMAN BLADDER CANCER CELLS TO MIR-145 INHIBITION OF ANCHORAGE-INDEPENDENT GROWTH THROUGH REGULATION OF FOXO1 EXPRESSION

Abstract

You have accessJournal of UrologyBladder Cancer: Basic Research III1 Apr 2015MP49-06 STAT3 ACTIVATION STATUS CONTRIBUTES TO THE DIFFERENTIAL RESPONSES OF METASTATIC AND NO-METASTATIC HUMAN BLADDER CANCER CELLS TO MIR-145 INHIBITION OF ANCHORAGE-INDEPENDENT GROWTH THROUGH REGULATION OF FOXO1 EXPRESSION Guosong Jiang, Jingxia Li, Moon-Shong Tang, Xue-Ru Wu, and Chuanshu Huang Guosong JiangGuosong Jiang More articles by this author , Jingxia LiJingxia Li More articles by this author , Moon-Shong TangMoon-Shong Tang More articles by this author , Xue-Ru WuXue-Ru Wu More articles by this author , and Chuanshu HuangChuanshu Huang More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.510AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES miR-145 was reported to be the most frequently downregulated miRNA in bladder cancer. However, the accurately determining of the networks regulated by miRNA in a specific condition is of great important. In this study, we address the stage-specific effects of miR-145 on bladder cancer. METHODS The expression of miR-145 was assessed by real-time RT-PCR. Soft agar assay was used to determine anchorage-independent growth of the cancer cells. RT-PCR was used to evaluate mRNA expression, and western blot was used to detect the expression of protein level. Luciferase activity was evaluated by the Dual-Luciferase Reporter Assay. RESULTS miR-145 was upregulated in human bladder cancer metastatic tissues in comparison to non-metastatic tissues and in metastatic T24T cells compared to parental non-metastatic T24 cells. Forced expression of miR-145 inhibited anchorage-independent growth of T24 cells, whereas it promoted growth of T24T cells. Overexpression of miR-145 resulted in the upregulation of both mRNA and protein levels of forkhead box class O1 (FOXO1) and its downstream effector, Cyclin-dependent kinase inhibitor 1B, in T24 cells, while they were downregulated by miR-145 in T24T cells. Moreover, knockdown of FOXO1 abolished the growth inhibition by miR-145 in T24 cells. Further studies showed that miR-145 could block FOXO1 mRNA 3'UTR activation in both T24 and T24T cells by targeting miR-145 binding site. On the other hand, miR-145 was demonstrated to suppress STAT3 activation and increase FOXO1 promoter transcription activation in T24 cells, and the mutation of STAT3 binding site at FOXO1 promoter effectively diminished the effects. In contrast, miR-145 overexpression did not show observable induction of FOXO1 promoter transcription activation in T24T cells that STAT3 was constitutively activated, whereas knockdown of STAT3 could restore the response of miR-145 induction of FOXO1 promoter transactivation, upregulation of FOXO1 protein expression and inhibition of growth in T24T cells. CONCLUSIONS STAT3 activation status contributes to the differential responses of metastatic and no-metastatic bladder cancer cells to miR-145 inhibition of growth through regulation of FOXO1 expression. Our findings reveal the stage-specific function of miR-145 in bladder cancer, and provide novel useful information of the future potential utilization of miR-145 for therapy of bladder cancer. © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e605 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Guosong Jiang More articles by this author Jingxia Li More articles by this author Moon-Shong Tang More articles by this author Xue-Ru Wu More articles by this author Chuanshu Huang More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...