MP08-17 BIOMARKER-TARGETED NOVEL COMBINATION FOR RENAL CELL CARCINOMA

Abstract

You have accessJournal of UrologyKidney Cancer: Basic Research & Pathophysiology I (MP08)1 Apr 2020MP08-17 BIOMARKER-TARGETED NOVEL COMBINATION FOR RENAL CELL CARCINOMA Eric Webb*, Soum Lokeshwar, Rashid Sayyid, Andre Jordan, Zachary Klaassen, Martha Terris, and Vinata Lokeshwar Eric Webb*Eric Webb* More articles by this author , Soum LokeshwarSoum Lokeshwar More articles by this author , Rashid SayyidRashid Sayyid More articles by this author , Andre JordanAndre Jordan More articles by this author , Zachary KlaassenZachary Klaassen More articles by this author , Martha TerrisMartha Terris More articles by this author , and Vinata LokeshwarVinata Lokeshwar More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000828.017AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The survival of patients with metastatic renal cell carcinoma (mRCC) is < 10% at 5-years, despite treatment. Hyaluronic acid (HA) promotes tumor growth and metastasis through its receptors CD44 and RHAMM. 4-methylumbelliferone (MU) is a non−toxic small molecule HA synthesis inhibitor and down regulates CD44 and RHAMM mRNA. In this study we examined if MU in combination with an FDA-approved treatment could abrogate mRCC in preclinical models and whether the target can be validated in a clinical cohort and TCGA dataset. METHODS: Response of Vector-only (EV), HAS3-overexpressing (HAS3) or HAS3-knockdown (HAS3-KO) transfectants of 786-O and Caki-1 cells, primary RCC spheroids and endothelial cells co-cultured with these transfectants to MU combined with Sorafenib (SF), Sunitinib or Everolimus was examined in proliferation, apoptosis, motility and invasion assays. Immunoblotting and RT-qPCR were performed for downstream signaling studies. HAS3 promoter was cloned and effect of SF and HC on HAS3 promoter activity was determined. Treatment efficacy was evaluated in the Caki−1 s.c. and orthotopic xenograft models. HAS3 levels were analyzed in a clinical-cohort (51 normal; 83 tumor), RCC TCGA-dataset (TCGA-cohort; n=542). RESULTS: MU synergized with SF to inhibit RCC cell and primary tumor spheroid proliferation > 90%, motility/invasion (>80%) and induced apoptosis (5-fold). Combination of MU (0.1, 0.2 mM) with SF (5 µM) downregulated (>80%) HAS3 expression, HAS3 promoter activity and HA synthesis in RCC cells. While HAS3 transfectants were resistant to SF+MU treatment, HAS3-KO transfectants were sensitive to SF alone. Endothelial cells co-cultured with HAS3 transfectants were resistant to the combination. SF+MU up-regulated apoptosis effectors, but downregulated CD44, RHAMM, and phospho-Met levels in EV but not in HAS3 transfectants. MU (100 or 200 mg/kg) and SF (30 mg/kg) oral combination abrogated Caki-1 tumor growth (>80%), without serum/tissue toxicity. MU+SF treatment decreased HAS3/HA levels, Ki67 index and microvessel density. HAS-overexpressing tumors were resistant to treatment. HAS3 levels were 4-fold elevated in mRCC patients’ tumors and significantly predicted metastasis (P=0.0086). HAS3 levels also significantly correlated with overall survival in TCGA dataset (P=0.029). CONCLUSIONS: This is the first study to demonstrate that HAS3 significantly predicts metastasis. By downregulating HAS3 expression, MU+SF combination effectively abrogates RCC growth and metastasis. HAS3 is a potential biomarker to predict clinical outcome in RCC patients. Source of Funding: 5R01CA176691-05 (VBL); 1F31 CA210612-01 to ARJ © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e112-e112 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information Eric Webb* More articles by this author Soum Lokeshwar More articles by this author Rashid Sayyid More articles by this author Andre Jordan More articles by this author Zachary Klaassen More articles by this author Martha Terris More articles by this author Vinata Lokeshwar More articles by this author Expand All Advertisement PDF downloadLoading ...