International journal of cancer. Journal international du cancer
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Steroid hormones, especially testosterone, play important roles in the carcinogenesis of prostate cancer, and several studies have reported changes in risk with polymorphisms of genes involved in steroid metabolism. One example is the CYP17 gene, which has a polymorphic T-to-C substitution in the 5'-untranslated region giving rise to A1 (T) and A2 (C) alleles. Steroid 5alpha-reductase type II (SRD5A2), which converts testosterone to the metabolically more active dihydrotestosterone, exhibits 2 polymorphisms: V89L, which substitutes leucine for valine at codon 89, and A49T, which substitutes threonine for alanine at codon 49. ⋯ The frequency of the SRD5A2 LL genotype in cases (29.3%) was also slightly higher than in controls (24.6%), but this was not significant. Regarding the A49T polymorphism of SRD5A2, we could not detect the T allele in any of the examined samples. These data suggest a significant association between the CYP17 polymorphism and prostate-cancer risk among the Japanese.