108 IGFBP-4 ACTIVATES THE WNT/BETA-CATENIN SIGNALING PATHWAY AND INDUCES M-CAM EXPRESSION IN HUMAN RENAL CELL CARCINOMA

Abstract

You have accessJournal of UrologyKidney Cancer: Basic Research1 Apr 2011108 IGFBP-4 ACTIVATES THE WNT/BETA-CATENIN SIGNALING PATHWAY AND INDUCES M-CAM EXPRESSION IN HUMAN RENAL CELL CARCINOMA Koji Ueno, Hiroshi Hirata, Z. Laura Tabatabai, Yuji Hinoda, Peter R. Carroll, and Rajvir Dahiya Koji UenoKoji Ueno San Francisco, CA More articles by this author , Hiroshi HirataHiroshi Hirata San Francisco, CA More articles by this author , Z. Laura TabatabaiZ. Laura Tabatabai San Francisco, CA More articles by this author , Yuji HinodaYuji Hinoda Ube, Japan More articles by this author , Peter R. CarrollPeter R. Carroll San Francisco, CA More articles by this author , and Rajvir DahiyaRajvir Dahiya San Francisco, CA More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.174AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES The Wnt/beta-catenin signaling pathway is inactivated by Wnt antagonists in most cancers. IGFBP-4 is an antagonist of the Wnt/beta-catenin signaling pathway, however its function is not currently understood in renal cell carcinoma (RCC). METHODS The expression levels of IGFBP-4 protein in kidney tissue microarray were examined by immunostaining using antibody to IGFBP-4. The IGFBP-4 mRNA expression level was analyzed in a normal kidney cell line (HK-2), primary renal cancer cell lines (A498, 769-P) and metastatic renal cancer cell lines (ACHN, Hs891.T). To examine the function of IGFBP4, MTS, matrigel invasion, colony formation and wound healing assays were performed using 769-P mock and stable IGFBP-4 transfected cells. To screen for metastatic related genes in IGFBP-4 stable cells, cDNA PCR array was performed with a Human RT2 Profiler PCR Array. We investigated mRNA expression of the MMP family and observed Tcf transcriptional activity to monitor the Wnt/beta-catenin dependent pathway in 769-P mock and IGFBP-4 stable transfected cells. To analyze the role of IGFBP-4 on metastatic RCC cell lines, IGFBP-4 mRNA was knocked down using a siRNA technique. RESULTS We initially found that the expression of IGFBP-4 was significantly lower in primary RCC and higher in metastatic RCC compared to normal human kidney tissues. To assess the function of IGFBP4, we established IGFBP4 transfectants (primary renal cancer cell line) and performed functional analyses including Tcf reporter assays, cell viability, invasive capability, mortality, and in vivo tumor growth. Interestingly IGFBP-4 transfectants promoted cell growth (in vitro and in vivo), invasion, and motility in primary renal cancer. Tcf transcriptional activity was significantly increased in IGFBP-4 transfectants compared to mock cells and beta-catenin expression was increased. Also the beta-catenin downstream effector, MT1-MMP showed increased expression in IGFBP4 transfectants. Additionally IGFBP4 induced the expression of M-CAM, a marker of tumor progression. In order to assess the role of IGFBP4 in metastatic renal cancer, IGFBP-4 mRNA in a metastatic renal cancer cell lines (ACHN) was knocked-down using a siRNA technique. The cell growth and motility was decreased in si-IGFBP4 transfected ACHN cells compared to cells transfected with control siRNA. CONCLUSIONS This is a first report documenting that IGFBP-4 expression in RCC activates cell growth, metastasis, Wnt/beta-catenin signaling and may be involved in RCC metastasis. © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185Issue 4SApril 2011Page: e46 Peer Review Report Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information Koji Ueno San Francisco, CA More articles by this author Hiroshi Hirata San Francisco, CA More articles by this author Z. Laura Tabatabai San Francisco, CA More articles by this author Yuji Hinoda Ube, Japan More articles by this author Peter R. Carroll San Francisco, CA More articles by this author Rajvir Dahiya San Francisco, CA More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...