Nitric oxide synthase 2 gene polymorphisms are associated with prostatic volume in Korean men with benign prostatic hyperplasia.

The precise aetiology of benign prostatic hyperplasia (BPH) remains unclear; however, it is known that immunological inflammatory processes have a role in the pathogenesis of BPH initiation and progression. Nitric oxide synthase 2 (NOS2) inducible expression is closely correlated with prostatic disease, including prostate cancer and BPH. The aim of this study was to investigate the relationship between NOS2 polymorphisms and BPH. With a cohort of 205 controls and 229 BPH subjects, we genotyped three single nucleotide polymorphisms (SNPs) in the NOS2 gene, including rs2779248 (promoter, -278 T/C), rs10459953 (5'-untranslated region) and rs2297518 (exon 16, missense, Ser608Leu), using direct sequencing and restriction fragment length polymorphism. The genotypic and allelic frequencies between control and BPH subjects were compared, and the associations among the BPH subjects were analyzed. SNPStats, SNPAnalyzer and HelixTree programmes were used to analyze SNPs. There was no association on SNPs between control and BPH subjects. When BPH subjects were analyzed, there was no association on SNPs between the low and high prostate-specific antigen groups. However, one SNP (rs10459953, odds ratio [OR] = 0.44, 95% confidence interval [CI] = 0.29-0.65, P < 0.0001, in codominant model; OR = 0.23, 95% CI = 0.12-0.46, P < 0.0001, in dominant model; and OR = 0.46, 95% CI = 0.24-0.86, P = 0.015, in recessive model) was associated with prostatic volume in BPH. We detected a strong association in genotype frequencies of NOS2 SNP (rs10459953) between subjects with small and large prostatic volume in BPH. The result suggests that NOS2 may be associated with prostatic volume in BPH.