Investigation of the roles of IL-18 (-607 C/A) and IL-18 (-137 G/C) gene variations in bladder cancer development: case-control study

Abstract

Background: The purpose of our study is to investigate the roles of IL-18 gene variations in bladder cancer development in Thrace population of Turkey.

Methods: This study was carried out with 103 bladder cancer patients and 81 healthy controls. Genotype distributions of IL-18 (-137 G/C) and IL-18 (-607 C/A) gene variations were determined using polymerase chain reaction (PCR) method.

Results: The CC homozygous genotype for IL-18 (-607 C/A) gene variation was significantly higher in patients with bladder cancer compared to healthy controls (OR 0.345, 95% Cl 0.186-0.639, p = 0.001). Besides this, allele frequencies of IL-18 (-137 G/C) and IL-18 (-607 C/A) gene variations in patient with bladder cancer and healthy control groups were significantly different from the Hardy-Weinberg distribution (p < 0.05). For IL-18 (-137 G/C) and IL-18 (-607 C/A) gene variations, significant difference was determined between the bladder cancer patient and healthy control groups in terms of GC-CA (OR 0.381, 95% Cl 0.203-0.714, p = 0.002), GC-CC (OR 2.147, 95% Cl 1.013-4.550, p = 0.043), GG-AA (OR 0.431, 95% Cl 0.365-0.509, p = 0.049), and GG-CC (OR 2.476, 95% Cl 1.177-5.208, p = 0.015) haplotypes.

Conclusion: In our study, CC genotype of IL-18 (-607 C/A) gene variation was determined as genetic risk factor for bladder cancer development. In bladder cancer patient and healthy control groups, G and C allele frequencies of IL-18 (-137 G/C) gene variation, and C and A allele frequencies of IL-18 (-607 C/A) gene variation were determined significantly different from the Hardy-Weinberg distribution.

Keywords: Bladder cancer; IL-18 (-137 G/C) gene variation; IL-18 (-607 C/A) gene variation; IL-18 gene; PCR.