386 TARGETING RHAMM, A METASTASIS PREDICTOR, FOR KIDNEY CANCER THERAPY

Abstract

You have accessJournal of UrologyKidney Cancer: Basic Research1 Apr 2011386 TARGETING RHAMM, A METASTASIS PREDICTOR, FOR KIDNEY CANCER THERAPY Jeffrey Gahan, Anaid Benitez, Travis Yates, Andrew Chi, Vincent Bird, and Vinata Lokeshwar Jeffrey GahanJeffrey Gahan Miami, FL More articles by this author , Anaid BenitezAnaid Benitez Miami, FL More articles by this author , Travis YatesTravis Yates Miami, FL More articles by this author , Andrew ChiAndrew Chi Miami, FL More articles by this author , Vincent BirdVincent Bird Gainesville, FL More articles by this author , and Vinata LokeshwarVinata Lokeshwar Miami, FL More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.474AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Up to 25% of patients with renal cell carcinoma (RCC) have metastasis at initial diagnosis. Current targeted therapies (e.g., Sorafenib) are not curative and the 5-year survival of these patients is <10%. Molecular determinants of RCC growth and metastasis may be accurate prognostic markers for metastasis and could be targeted for therapy. We evaluated the expression of 5 genes (and their splice variants) as prognostic indicators. We also tested the therapeutic efficacy of the combination of 4-methylumbelliferone (4-MU), a non-toxic, orally bioavailable hyaluronic acid (HA) synthesis inhibitor and Sorafenib (Soraf). METHODS Tumor specimens were collected from RCC patients undergoing nephrectomy (n=81; T1, 40; T2+, 41; Grade 1, 5; Grade 2, 32; Grade 3, 25; Grade 4, 19). Nine patients developed metastasis within 24 months. Tissue-RNA was subjected to Q-PCR for HA receptors (CD44, RHAMM), chemokine receptors (CXCR4, CXCR7); and chemokines (SDF1-a,b,g). mRNA levels were correlated with metastasis by logistic regression. Effect of 4-MU, Soraf and 4-MU+Soref on cell proliferation, cell cycle and apoptosis was examined in RCC cells (HTB46, 786-O, ACHN, 769-P) by cell counting, flow cytometry and Cell Death ELISA. Boyden chamber was used for motility assay. Effect on cell cycle, apoptosis, and HA receptor levels was evaluated by immunoblotting and Q-PCR. RESULTS RHAMM expression (157±124) was 8-fold elevated in tumors which later metastasized when compared to those which did not (20.1±31.5; P=0.005). In univariate analysis age, grade, stage and RHAMM levels significantly correlated with metastasis. In multivariate analysis, only RHAMM significantly correlated with metastasis (P=0.03; chi-sq = 4.6; sensitivity 88.9%; specificity 90%). Combination of 4-MU (0.2 mM) and Soraf (2.5 or 5 mM), at non-cytotoxic doses caused 60-90% inhibition in proliferation after 48–72 h treatment and motility in RCC cells. Only the combination induced cycle arrest in late S- and G2-M phases (1.5–2.5-fold) and induced apoptosis (3–4-fold). Cell cycle arrest and apoptosis were confirmed by increased phospho-Chk1 and PARP levels. 4-MU+Soraf combination down regulated CD44 and RHAMM mRNA levels by 2- and 68-fold, respectively. CONCLUSIONS RHAMM expression in RCC tissues is potentially an independent prognostic indicator for metastasis. 4-MU+Soraf combination which targets RHAMM expression inhibits RCC cell growth and motility. © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185Issue 4SApril 2011Page: e156 Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information Jeffrey Gahan Miami, FL More articles by this author Anaid Benitez Miami, FL More articles by this author Travis Yates Miami, FL More articles by this author Andrew Chi Miami, FL More articles by this author Vincent Bird Gainesville, FL More articles by this author Vinata Lokeshwar Miami, FL More articles by this author Expand All Advertisement Advertisement PDF DownloadLoading ...