GPx-1 polymorphism (rs1050450) contributes to tumor susceptibility: Evidence from meta-analysis

Abstract

Purpose: Accumulating evidences implicate the selenium-containing cytosolic glutathione peroxidase, GPx-1, as a determinant of cancer risk and a mediator of the chemopreventive properties of selenium. Since the identification of a well-characterized functional polymorphism named Pro198Leu (rs1050450 C>T) in GPx-1, abundant studies have evaluated the association between Pro198Leu polymorphism and tumor risk in diverse population. But, the available results are conflicting. Methods: To derive a more precise estimation, we performed a meta-analysis based on 14,372 cases with different tumor types and 18,081 controls from 31 published case-control studies. Published literature from PubMed was retrieved. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to estimate the strength of the association. Results: Overall, the results indicated that individuals who carried variant Leu allele (Pro/Leu and Leu/Leu) were associated with an increased cancer risk [odds ratio (OR) = 1.12, 95% confidence interval (CI) = 1.02-1.23] in a dominant genetic model. In further subgroup analyses, the increased risk of cancer was observed in subgroup of Asians and sample size more than 500 subjects. Conclusion: These results suggest that the GPx-1 Pro198Leo polymorphism contributes to cancer susceptibility through a disturbed antioxidant balance. © 2011 Springer-Verlag.