Single nucleotide polymorphism and haplotype association of the interleukin-8 gene with nasopharyngeal carcinoma

The cytokine interleukin-8 (IL-8) may play a role in the pathogenesis of nasopharyngeal carcinoma (NPC) through the modulation of tumor immune response or enhanced angiogenesis. Polymorphism of IL-8 gene, which may affect the production level of cytokine, has been inversely associated with a number of cancers. To test this hypothesis, we investigated the relationship of IL-8 gene polymorphisms and NPC in a Chinese population. We analyzed single nucleotide polymorphisms (SNPs) of IL-8 gene − 845 T/C, − 738 T/A, − 353 A/T, − 251 A/T and + 678 T/C in 280 patients with NPC and 290 age and sex matched controls, using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and polymerase chain reaction-sequence specific primers method (PCR-SSP). There were significant differences in the genotype and allele distribution of − 251 A/T polymorphism of the IL-8 gene among cases and controls. The − 251 AA and AT genotypes were associated with a significantly increased risk of NPC as compared with the − 251 TT genotypes (OR = 1.820, 95% CI, 1.120–2.959, P = 0.015 and OR = 1.590, 95% CI, 1.104–2.290, P = 0.013, respectively). Haplotype analysis revealed that the homozygosity of the AAT haplotype (defined by SNPs at positions − 353, − 251 and + 678) of IL-8 gene conveys the highest risk for NPC compared with the homozygosity for the TTC haplotype (OR = 1.396; 95% CI, 1.064–1.831; P = 0.016). The − 251 A/T polymorphism of IL-8 and its haplotype are associated with NPC in a Chinese population. Our data suggests that IL-8 gene may play a role in the development of NPC.