Variations in the peroxisome proliferator-activated receptor-γ gene and melanoma risk

Abstract

There is strong evidence to suggest that the peroxisome proliferator-activated receptor (PPAR)-γ, a member of the nuclear receptor family of transcriptional regulators, mediates tumor suppressive activities in a variety of human cancers. Recently, PPARγ agonists were found to inhibit growth of melanoma cell lines. Here, we tested the possibility that variations in the gene encoding PPARγ ( PPARG) influence melanoma risk. Two variations of PPARG (P12A[rs1801282] and C161T [rs3856806]) were investigated in two independent case–control studies with a total of 832 melanoma patients and 790 control individuals. In the first study, homozygous carriers of the rare *T allele of the C161T polymorphism in exon 6 of PPARG were significantly more common among patients with melanoma than among healthy subjects (6.0 vs. 2.0%; P=0.0096) and this association was independent of clinical risk factors such as skin type and nevus count (odds ratio 5.18; 95% confidence interval 1.68–15.96; P=0.0041). This finding, however, could not be replicated in the second case–control study. We therefore conclude that the investigated PPARG polymorphisms are not likely to constitute a significant risk factor for the development of melanoma among German Caucasians.