The Association Of Interleukin-6 Gene Polymorphisms And Lung Cancer In Population Of North China

Objective: The aim of this study was to To investigate the association between the polymorphisms of interleukin-6(IL-6) and the susceptibility of lung cancer in population of north china.Methods: Genomic DNA of 175 lung cancer patients and 200 healthy controls in population of north china were extracted from the peripheral blood leukocytes. Then three fragments covering position -174,position -572 and position -597 of the IL-6 gene were amplified by polymerase chain reaction (PCR). The polymorphisms of patients were revealed by restriction fragment length polymorphism(RFLP). Software Unconditional logistic regression model was used to analyze the statistical association of genotypes in three groups adjusted by gender,smoking and age.Results: No polymorphism at position -174 was dectected in any of the 375 participants. There were C/C,G/C,G/G genotypes in position -572. Only three participants with G/A genotype was found,others were G/G genotype (99.2%),no A/A genotype was revealed in position -597. A preliminary case-control analysis of the population revealed significant difference in genotype frequency of position -572 polymorphism(G/C genotype and G/G genotype compared with C/C genotype),which obviously different from those in Germany and Swedish Caucasians. Judging by pathology,the decreased susceptibility was associated with squamous cell carcinoma (P=0.004 OR=0.353 95%CI=0.175-0.713 ) but not adenocarcinoma (P=0.127 OR=0.657 95%CI=0.383-1.127) .Stratified by sex, age, history of smoking and pathology: male,age between 40 and 70 and without smoking carrying with G/C or G/G will have decreased susceptibility to lung cancer.Conclusion: Our data suggest that there is significant difference in the polymorphism at position -572 of the interleukin-6 gene promoter, the risk at lung cancer decreases in G/C or G/G genotypes.