Interleukin-6 gene -174G>C and -636G>C promoter polymorphisms and prostate cancer risk

Abstract

Prostate cancer (PCa) is one of the most commonly diagnosed internal malignancies affecting men. Due to the important roles of IL-6 in different physiological and pathophysiological processes,IL-6polymorphisms may modulate PCa risk.IL-6−174 G>C (rs 1800795, also designated −236 G>C) and −636 G>C (rs 1800796, also designated −572 G>C) promoter polymorphisms have been implicated in PCa susceptibility, albeit still controversial. A literature search using PubMed and Highwire databases was conducted, resulting in eight case–control studies concerning theIL-6−174 G>C polymorphism (11,613 PCa cases and 13,992 controls) and four case–control publications regarding theIL-6−636 G>C polymorphism (1,941 PCa cases and 3,357 controls). In order to derive a more precise estimation, a meta-analysis based upon these selected case–control studies was performed. There was no significant association betweenIL-6−174 G>C polymorphism and PCa increased risk. Nevertheless, the presence of allele C and the CC genotype were statistically significantly associated with decreased PCa risk in the overall analysis forIL-6−636 G>C polymorphism. Additional studies in larger samples and analyses of functional repercussions of these SNPs in prostate tumor cells are necessary to validate these findings.