506 FUNCTIONAL ROLE OF LASP1 IN BLADDER CANCER CELL VIABILITY AND ITS REGULATION BY MICRORNAS (2011)

You have accessJournal of UrologyBladder Cancer: Basic Research1 Apr 2011506 FUNCTIONAL ROLE OF LASP1 IN BLADDER CANCER CELL VIABILITY AND ITS REGULATION BY MICRORNAS Takeshi Chiyomaru, Kazumori Kawakami, Hideki Enokida, Shuichi Tatarano, Kenryu Nishiyama, Naohiko Seki, and Masayuki Nakagawa Takeshi ChiyomaruTakeshi Chiyomaru Kagoshima, Japan More articles by this author , Kazumori KawakamiKazumori Kawakami Kagoshima, Japan More articles by this author , Hideki EnokidaHideki Enokida Kagoshima, Japan More articles by this author , Shuichi TataranoShuichi Tatarano Kagoshima, Japan More articles by this author , Kenryu NishiyamaKenryu Nishiyama Kagoshima, Japan More articles by this author , Naohiko SekiNaohiko Seki Chiba, Japan More articles by this author , and Masayuki NakagawaMasayuki Nakagawa Kagoshima, Japan More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.1202AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES MicroRNAs are small non-coding RNAs that negatively regulate protein-coding genes involved in the development of various cancers. In the last year, we presented that an actin filament bundling protein, fascin homolog 1 (FSCN1) might have an oncogenic function in bladder cancer (BC), and its expression was regulated by tumor suppressive miR-145 and miR-133a, which were commonly down-regulated in BC. Recently, LIM and SH3 Protein 1 (LASP1) as well as FSCN1 have been reported as actin filament bundling proteins in the same complexes attached to the inner surfaces of cell membranes. We hypothesize that LASP1 has an oncogenic function under the regulation of specific microRNAs. METHODS The expression levels of LASP1 mRNA were evaluated by real-time RT-PCR. LASP1 knockdown BC cell lines (BOY, KK47 and T24) were transfected by siRNA in order to examine cellular viability by XTT assay, wound healing assay, and matrigel invasion assay. We employed web-based software to search candidate microRNAs targeting LASP1 mRNA. The luciferase reporter assay was used to confirm the actual binding sites between the microRNAs and LASP1 mRNA. RESULTS Real-time RT-PCR showed that LASP1 mRNA expression was higher in 76 clinical BC specimens than in 10 normal bladder epitheliums (P < 0.05). Loss-of-function studies using si-LASP1-transfected BC cell lines demonstrated significant cell viability inhibitions (P < 0.0005), cell migration inhibitions (P < 0.0001), and decreases in the number of invading cells (P < 0.005) in the transfectants compared with the controls. Transient transfection of three microRNAs (miR-1, miR-133a and miR-218), which were predicted as the microRNAs targeting LASP1 mRNA by the web-based software, repressed the expression levels of mRNA and protein levels of LASP1. The luciferase reporter assay demonstrated that the luminescence intensity was significantly decreased in miR-1, miR-133a, and miR-218 transfectants (P < 0.05), suggesting that these microRNAs have actual target sites in the 3′ untranslated region of LASP1 mRNA. Furthermore, significant cell viability inhibitions occurred in miR-1, miR-133a, and miR-218 transfectants (P < 0.001). CONCLUSIONS Our data suggest that LASP1 may have an oncogenic function and that it might be regulated by miR-1, miR-133a, and miR-218, which may function as tumor suppressive microRNAs in BC. These pathways may play a critical role in BC development and serve as a novel therapeutic target in BC. © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185Issue 4SApril 2011Page: e205 Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information Takeshi Chiyomaru Kagoshima, Japan More articles by this author Kazumori Kawakami Kagoshima, Japan More articles by this author Hideki Enokida Kagoshima, Japan More articles by this author Shuichi Tatarano Kagoshima, Japan More articles by this author Kenryu Nishiyama Kagoshima, Japan More articles by this author Naohiko Seki Chiba, Japan More articles by this author Masayuki Nakagawa Kagoshima, Japan More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...