Abstract 4861: Identification of premalignant bladder markers using DNA microarray analysis of the UPII-SV40Tag model for invasive bladder UCC

Urothelial cell carcinoma of the bladder (UCC) ranks 5th in incidence of all cancers in the developed world, yet the mechanisms of its origin and progression remain poorly understood. A few urine-based tests for screening and surveillance are commercially available for bladder cancer, but there are no reliable non-invasive methods for detecting premalignant UCC. In order to determine molecular mechanisms involved in early UCC development and to identify new biomarkers for detection, diagnosis and prognosis of UCC, a transgenic mouse model for invasive bladder cancer (UPII-SV40Tag mice) was analyzed by DNA microarray technology. Genes that are differentially expressed between the bladders of UPII-SV40Tag mice and their age-matched wild type (WT) littermates at 3, 6, 20 and 30 weeks of age were identified. The ages selected correspond to premalignant, carcinoma in-situ, and early and later stage papillary UCC, respectively. Approximately 1,900 unique genes were differentially expressed (≥ 3-fold difference at one or more time points) between WT and UPII-SV40Tag urothelium during the time course of tumor development. A high proportion of cell cycle regulatory genes and proliferation signaling genes were more strongly expressed in the UPII-SV40Tag bladder urothelium. Several of the genes upregulated and downregulated in UPII-SV40Tag urothelium were tested as biomarkers for premalignancy, including autocrine motility factor (AMFR), hyaluronan-mediated motility receptor (Hmmr), proliferating cell nuclear antigen (PCNA), Rac GTPase activating protein 1 (RacGAP1), superoxide dismutase 3 (SOD3), collagen 1a2 (Col1a2), and others. These tests were performed by analyzing urine samples from a recently completed Phase II, randomized, placebo controlled chemoprevention trial (N01 CN85186, PI: A. Sabichi) that was designed to test whether celecoxib can prevent recurrence in patients successfully treated by transurethral resection (TUR) for non-muscle invasive bladder cancer. Positive markers, Hmmr and RacGAP1, and a negative marker, Col1a2, have been identified in patient urine samples that show promise for detecting UCC recurrence. We are currently attempting to determine the biological function of Hmmr, and RacGAP1 in bladder premalignancy. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4861. doi:10.1158/1538-7445.AM2011-4861