Abstract 5241: Nitric oxide-releasing naproxen prevents muscle invasive bladder cancer

Abstract

Abstract Bladder cancer is the second most common and a leading cause of death among genitourinary cancers worldwide. Particularly, untreated muscle invasive bladder cancer has high mortality (>85% patients) leading to death within 2 years of diagnosis. Preventing this deadly form is highly imperative since the currently available options to patients with invasive disease remained essentially unchanged and no effective drugs have been approved in past two decades. Several non-steroidal anti-inflammatory agents (NSAIDs) have shown promising chemopreventive activity in many cancers. The common adverse events with NSAIDs, especially gastrointestinal (GI) morbidities, including complications in both upper and lower GI tract drives the need for development of safer agents. To overcome this various nitric oxide (NO)-linked NSAIDs have been synthesized. Here we investigated the NO-releasing Naproxen (NO-Naproxen) with proven anti-inflammatory and GI protecting effects for its efficacy in preventing bladder cancer. Transgenic mouse model (UPII-SV40T; n = 30/group) that develop muscle invasive urothelial tumors were generated, genotyped and fed modified AIN-76A diet containing NO-naproxen (0, 300 and 600 ppm) starting at 6 weeks of age. At 40 weeks age, control (0 ppm) and experimental diet (300 and 600 ppm) fed mice were euthanized and urinary bladders were analyzed. Control diet fed male and female transgenic mice developed high grade, invasive transitional cell carcinoma (TCC) of bladder resulting in significant increase in bladder weights (140.2±9.8 mg; p<0.0001 and 34.2+0.8 mg; p<0.0001 respectively) compared with wild type mice (27.3±0.8 mg and 14.8±0.53 mg). These tumors had a significant disregulation of proliferation, cell cycle markers and antioxidant enzymes similar to human tumors. NO-Naproxen administered mice had normal body weight gain; and gross tissue analysis and showed no signs of overt toxicities. Treatment of transgenic mice with NO-Naproxen led to significant suppression of bladder weight in both genders (up to 58% in males, p<0.0001; up to 21% in females, p<0.005) compared to control group. While there was no dose-dependent increase in tumor inhibition, mice on NO-Naproxen diet had developed significantly less muscle invasive tumors suggesting inhibitory effect of treatment on disease progression. Urothelial tumor progression to invasive TCC was inhibited in both male (up to 54%; p<0.005) and females mice (up to 85%; p<0.0001) of the experimental diet groups. Molecular analysis of urothelial tumors via real-time PCR, IHC and/or western blotting showed inhibitory effect of NO-Naproxen on proliferation and inflammatory markers (PCNA, Cyclins, COX2, and IL1b) and showed modulation of antioxidant enzymes (CAT, GPx, GST, NQO1, and SOD3). Our results suggest that NO-Naproxen may be a promising agent for preventing urothelial TCC and warrants further investigation. (Supported in part by NCI-CN53300) Citation Format: Venkateshwar Madka, Altaf Mohammed, Qian Li, Yuting Zhang, Stanley Lightfoot, Xue-Ru Wu, Vernon Steele, Levy Kopelovich, Chinthalapally V. Rao. Nitric oxide-releasing naproxen prevents muscle invasive bladder cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5241.