No association between genetic polymorphisms of the Interleukin-4 Receptor alpha gene and cervical cancer in Korean population

Lee, Sang Eun; Kim, Jae Weon; Park, Noh Hyun; Song, Yong Sang; Kang, Soon Beom; Lee, Hyo Pyo

Abstract

OBJECTIVE
Genetic variants of IL-4Ralpha polymorphisms of Ile50Val were known to upregulate receptor response to IL-4. IL-4 was found in cervical cancer cell lines and known to promote cervical carcinogenesis and the progression from cervical intraepithelial neoplasia to cervical cancer. So, we aim to explore whether the Ile50Val polymorphisms of Interleukin-4 receptor alpha (IL-4Ralpha) gene increase cervical cancer risk, which could serve as useful genetic markers for assessing the risk of the development and progression of cervical cancer in Korean population.
METHODS
The blood samples of 228 cervical cancer patients who were diagnosed at Seoul National University Hospital from 1999 to 2002 and 204 subjects who had screened at the health care system of Seoul National University Hospital and confirmed as non-cancer controls, were obtained. PCR amplification and TagMan assay were used. We used the chi-square test to evaluate whether the distribution of genotypes varied significantly between cervical cancer and controls. Odds Ratio and 95% confidence intervals were calculated using logistic regression test after age adjusting.
RESULTS
The distribution of homozygotes and heterozygotes closely approximated the expected values under Hardy-Weinberg equilibrium in cases and controls (p=0.33, chi-square=0.94; p=0.15, chi-square=2.04). In cervical cancer group, allele frequency of Ile was 46.1%, in comparison with 43.4% in control group which showed no significant difference statistically (p=0.52). Using subject with the Val/Val homozygote as a reference group, we found no association between the Ile/Val and Ile/Ile genotypes and the risk of cervical cancer with age adjusted regression analysis (aOR=1.09, 95% CI=0.70-1.72, p=0.7; aOR=1.21, 95% CI=0.67-2.19, p=0.52). Subanalyses of the cervical cancer according with clinical stage, histologic type, lymph node status and parametrial invasion status showed no statistically significant association with these polymorphisms.
CONCLUSION
The polymorphisms of the IL-4Ralpha gene are neither associated with increasing risk of cervical cancer nor more vulnerable for cervical cancer progression in Korean population.