Abstract 3406: Activity of catechol-O-methyltransferase gene promoter polymorphisms in renal cancer cells

Abstract

Abstract Catechol-compounds such as 4-hydroxy-estrogen have been shown to play a role in the renal carcinogenesis process. To counter the effects of the highly reactive and mutagenic catechol-estrogens, the catechol-O-methyltransferase (COMT) gene detoxifies these compounds by forming methoxy compounds, which have been shown to be biologically inactive. Proper COMT function is thus vital for cells and a mechanism by which activity levels can be affected is through polymorphisms. The Val(158)Met polymorphism that correlates with renal cancer has been shown to reduce COMT enzymatic activity, but also of importance are those variants in the promoter region which can lead to alterations in gene expression levels. The aim of this study was to determine if polymorphisms of the COMT promoter can influence their transcription levels. To examine this, plasmids containing wildtype regions of the COMT promoter were obtained and site-directed mutagenesis used to create polymorphic variants. Constructs were then transfected into the Caki-1 renal cell line to measure their effects on gene expression by using a luciferase reporter assay. A total of 8 polymorphic sites covering the distal and proximal promoter region were evaluated. Results indicate that the variant at polymorphic sites rs2020917 (C to T), rs13306278 (C to T), and rs6269 (A to G) caused a significant reduction (P<0.01) whereas rs165656 (G to C) and rs165722 (C to T) caused a significant increase (P<0.01) in luciferase activity. No differences were observed for rs737865 (A to G), 4646312 (T to C), and rs3810595 (G to C). These results demonstrate polymorphisms of the COMT promoter region to cause altered expression levels in renal cells and warrant further studies with clinical case-control specimens to determine their associations for renal cell cancer. Citation Format: Inik Chang, Shinichiro Fukuhara, Darryn K. Wong, Ankurpreet Gill, Varahram Shahryari, Soichiro Yamamura, Shahana Majid, Sharanjot Saini, Hiroshi Hirata, Koji Ueno, Guoren Deng, Rajvir Dahiya, Yuichiro Tanaka. Activity of catechol-O-methyltransferase gene promoter polymorphisms in renal cancer cells. [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 3406. doi:10.1158/1538-7445.AM2014-3406