Interleukin-6-174 G/C Polymorphism is Not Associated with IL-6 Expression and Susceptibility to Sporadic Colon Cancer

Abstract

Interleukin-6 (IL-6) has been implicated in tumorigenesis; however, its role is still far from being clearly defined. Regulation of IL-6 expression is highly complex, and additional complexity is introduced by single-nucleotide polymorphisms in the IL-6 gene. These single-nucleotide polymorphisms might influence mRNA transcription, which might in turn result in increased susceptibility to certain tumors. The aim of this study was to analyze IL-6 mRNA and protein expressions in sporadic colon cancer. Influence of IL-6-174 G/C polymorphism on IL-6 mRNA expression and sporadic colon cancer susceptibility was evaluated as well. The frequency of IL-6-174 G/C was analyzed by polymerase chain reaction-restriction fragment length polymorphism analysis. IL-6 mRNA and protein expressions were analyzed by real-time reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry. No statistically significant difference in IL-6 mRNA expression in tumor tissue compared with the corresponding normal tissue was observed (p = 0.116). No correlation was found between IL-6 mRNA and protein expressions and clinicopathological features of sporadic colon tumors. There was no association of IL-6-174 G/C genotypes with IL-6 mRNA expression in colon tumors and corresponding normal mucous tissue (p = 0.355; p = 0.152). Finally, there was no association of IL-6-174 G/C with susceptibility to sporadic colon cancer.