Abstract 1146: Biomarker-driven targeted oral treatment strategy for bladder cancer

Abstract

Abstract INTRODUCTION AND OBJECTIVE: Hyaluronic acid (HA) family of molecules, HA-synthases (HAS-1,2,3), HA-receptors (CD44, RHAMM) and hyaluronidase (HYAL-1) are markers for bladder cancer (BCa) diagnosis and predicting prognosis. HA-family promotes tumor growth and metastasis by inducing epithelial mesenchymal transition (EMT). 4-Methylumbelliferone (4-MU) is an orally bioavailable dietary supplement that inhibits HA synthesis. We evaluated the expression of HA family and EMT markers in bladder tissues as well as the antitumor effects of 4-MU as a potential targeted therapeutic agent in preclinical models of BCa. METHODS: Quantitative PCR was used to measure mRNA expression of HA-family and EMT genes (β-catenin, Twist, and Snail) in 72 bladder tissue specimens (28 normal; 44 tumor); follow-up: 20.3±2.5 months; median 17 months. The effect of 4-MU (0-0.6 mM) on cell proliferation, apoptosis, intracellular signaling, and the expression of HA receptors, and EMT genes were examined in BCa cell lines by Q-PCR, immunoblotting, proximal ligation and PI-3K activity assays. Mechanism of action was analyzed by HA addition and mAkt overexpression. Effect of oral administration of 4-MU (100, 200-mg/kg) on tumor growth was analyzed in subcutaneous xenografts. RESULTS: HAS-1, -2 -3, HYAL-1 and Snail levels were 10-20-fold elevated in BCa tissues as compared to normal bladder (P<0.001). In univariate analysis, HAS-1, -2, HYAL-1 and Twist levels correlated with metastasis (P<0.001); HYAL-1 was an independent predictor of metastasis. 4-MU inhibited cell proliferation, chemotactic motility and invasion in a dose-dependent manner; 50-70% inhibition at IC50 (0.4 mM) for HA-synthesis inhibition. 4-MU induced apoptosis (>3-fold) via the death receptor pathway. 4-MU downregulated HA-signaling, specifically transcript and/or protein levels of CD44, RHAMM, p-Akt, β-catenin, pβ-catenin(S552). Snail and twist were downregulated by 2-5-fold, but pβcatenin((T41/S45), pGSK-3α/β and E-cadherin levels were increased. 4-MU also inhibited CD44/PI-3K complex formation and PI-3K activity. HA addition or myristoylated Akt expression attenuated 4-MU effects. In xenograft studies, 4-MU oral treatment abrogated tumor growth of established tumors (vehicle, day 50: 766±221 mm3; 4-MU: 128±61, day 50) by abrogating HA-synthesis. No weight loss or serum or organ toxicity was observed in treated mice. CONCULUSION: This study demonstrates that HA-family signaling is upregulated in BCa and can be specifically targeted for treatment by a non-toxic dietary supplement. Support: 7R01 CA072821-16; 7R01CA176691-03 Citation Format: Daley S. Morera, Andre Jordan, Vinata B. Lokeshwar. Biomarker-driven targeted oral treatment strategy for bladder cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1146. doi:10.1158/1538-7445.AM2017-1146