Evaluation of the Associations Between the Single Nucleotide Polymorphisms of the Promoter Region of the Tumor Necrosis Factor-α Gene and Nasopharyngeal Carcinoma

BackgroundTumor necrosis factor-α (TNF-α) is a pro-inflammatory cytokine and may act as an endogenous tumor promoter. Single nucleotide polymorphisms (SNPs) of the TNF-α gene promoter region have been found to be associated with certain cancers. We conducted a case-control study to evaluate the association between these SNPs and nasopharyngeal carcinoma (NPC).MethodsWe used polymerase chain reaction followed by restriction fragment length polymorphism analysis to determine the −308 TNF-α promoter genotypes of 89 NPC patients and 360 healthy controls. In 23 NPC patients and 50 controls, we determined the sequence from −1065 to −101 nucleotides of the TNF-α gene promoter region to detect SNPs.ResultsIn comparison with the controls, the NPC patients had higher proportions of men and carriage of IgA antibodies against the capsid antigen of Epstein-Barr virus, but had a similar carrier rate of the −308A allele (odds ratio [OR], 1.2; 95% confidence interval [CI], 0.7-2.0). The carriage of the -308A allele was not associated with the occurrence of NPC in comparison with -308G homozygosity. We also found no significant differences in the distributions of allelic variants of the −1031, −863, −857, and −806 loci of the TNF-α promoter region, but observed a lower carrier rate of the novel −806T allele in the NPC patients (OR, 0.3; 95% CI, 0.0-2.9).ConclusionAllelic variants of the TNF-α promoter gene may not be used as biomarkers of susceptibility to NPC. The role of the -806T allele needs to be studied further.