Background: Complement activation involved in the innate immunity and adaptive immunity and further contributed to the development of tumor growth. This study aimed to investigate the association of genetic variants in complement 3 (C3) and decay-accelerating factor (DAF) genes with the risk of gastric cancer.
Methods: This case-control study included 500 gastric cancer patients and 500 cancer-free controls. Based on the Chinese population data from HapMap database, we used Haploview 4.2 program to select candidate tag SNPs. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by logistic regression to evaluate the association of each genetic variant with the risk of gastric cancer.
Results: Among 12 tag SNPs of C3, no correlation was observed between C3 genetic variants and risk of gastric cancer. For tag SNPS of DAF, logistic regression analysis revealed that the carriers with DAF rs10746463 AA genotype had a significantly increased risk for developing gastric cancer (OR = 1.46, 95% CI = 1.01–2.10) when compared with GG genotype, but those carrying with rs10746463 AG genotype didn't (OR = 1.31, 95% CI = 0.98-1.75). When stratified by smoking status, we found that the risk of gastric cancer was associated with rs10746463 GA or AA genotype carriers among smoker with OR (95% CI) of 1.64 (1.06-2.54), but not among non-smoker (OR = 1.37, 95% CI = 0.97-1.94).
Conclusion: DAF rs10746463 polymorphism effects on the risk of developing gastric cancer in Chinese population.