Abstract 944: Translational implications of the 19q12 bladder cancer GWAS signal for aggressive bladder cancer

Abstract

Abstract Background: A genome-wide association study (GWAS) of bladder cancer identified a genetic marker rs8102137 within the 19q12 region as a novel susceptibility variant. This marker is located upstream of the CCNE1 gene, which encodes cyclin E, a cell cycle protein. Methods: Genetic fine mapping analysis of the CCNE1 region was performed using data from two bladder cancer GWAS, which included a total of 5,942 cases and 10,857 controls. Cyclin E protein expression was evaluated by immunohistochemistry analysis in 265 bladder tumors in relation to CCNE1 genetic variants and tumor characteristics. Functional effects of cyclin E over-expression were evaluated with cell cycle assays. Findings: The original GWAS marker rs8102137 represents a group of 47 linked SNPs (with r2≥0.7) associated with increased bladder cancer risk. From this group we selected a functional promoter variant rs7257330, which showed strong allele-specific binding of nuclear proteins in several cell lines. In both GWAS, rs7257330 was associated only with aggressive bladder cancer (muscle-invasive or high-grade non-muscle-invasive cancer), with a per-allele odds ratio (OR) =1.18 (95%CI=1.09-1.27, p=4.67×10-5). Cyclin E protein expression was increased in aggressive bladder tumors (p=0.013) and, independently, with each rs7257330-A risk allele (ptrend=0.024). Over-expression of recombinant cyclin E in cell lines caused significant acceleration of cell cycle. Conclusions: Molecular mechanisms linking the CCNE1 GWAS signal and aggressive bladder cancer risk are related to cyclin E over-expression and cell cycle regulation. In combination with other genetic and clinical markers, CCNE1 genetic variants may be translationally useful for early prediction of aggressive bladder cancer. Citation Format: Yi-Ping Fu, Indu Kohaar, Lee Moore, Petra Lenz, Jonine D. Figueroa, Wei Tang, Patricia Porter-Gill, Stephen Chanock, Stephen M. Hewitt, Debra T. Silverman, Nathaniel Rothman, NCI-GWAS Bladder Cancer Consortium, Ludmila Prokunina-Olsson. Translational implications of the 19q12 bladder cancer GWAS signal for aggressive bladder cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 944. doi:10.1158/1538-7445.AM2014-944