Association of interleukine-18 polymorphisms with susceptibility to prostate cancer in Iranian population

Interleukin-18 (IL-18) is a multifunctional cytokine that augments interferon-γ production, promotion of the Th1 immune response and acts as an important immunomediator in the development of some cancers. The current study aimed to analyze the association of the five most common polymorphisms in the IL-18 gene with prostate cancer in the Iranian population. We examined a possible association of IL-18 -137G>C, -607C>A, -656G>T, +105A>C and +127C>T polymorphisms with prostate cancer occurrence by PCR-RFLP assay. Odds ratio (OR) and 95% confidence interval (CI) were used to assess the strength of the association between IL-18 polymorphisms and prostate cancer. Statistical analysis revealed that individuals carrying the mutant homozygote genotype of IL-18 -607C>A (OR=2.251, 95% CI=1.062-4.768, p=0.034) and -137G>C (OR=2.364, 95% CI=1.121-4.984, p=0.024) polymorphisms had an increased risk of prostate cancer. However, for IL-18 -656G>T, +105A>C and +127C>T polymorphisms, there were no differential distributions of their genotypes between patients with prostate cancer and healthy subjects. Our results indicated that the IL-18 -137G>C and -607C>A polymorphisms were significantly associated with an increased risk of prostate cancer in the Iranian population. Thus, these polymorphisms might be used as a molecular biomarker in the early diagnosis of prostate cancer.