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

Abstract

Tumor necrosis factor-alpha (TNF-alpha) is a pro-inflammatory cytokine and may act as an endogenous tumor promoter. Single nucleotide polymorphisms (SNPs) of the TNF-alpha 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). We used polymerase chain reaction followed by restriction fragment length polymorphism analysis to determine the -308 TNF-alpha 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-alpha gene promoter region to detect SNPs. In 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-alpha promoter region, but observed a lower carrier rate of the novel -806T allele in the NPC patients (OR, 0.3; 95% Cl, 0.0-2.9). Allelic variants of the TNF-alpha promoter gene may not be used as biomarkers of susceptibility to NPC. The role of the -806T allele needs to be studied further.