Association of variants in the interleukin‐27 and interleukin‐12 gene with nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is multifactorial, and the genetic background may be a crucial etiologic factor. Interleukin‐12 (IL‐12) is a multifunctional cytokine that induces interferon (IFN)‐gamma secretion and plays an important role in antitumor immunity. Interleukin‐27 (IL‐27) is a novel IL‐12 family member, the present studies demonstrate that IL‐27 mediates potent antitumor activity. Variations in the DNA sequence in the IL‐12 and IL‐27 gene may lead to altered cytokines production and/or activity, and so this can modulate an individual's susceptibility to NPC. To test this hypothesis, we investigated the relationship of IL‐12 and IL‐27 gene polymorphisms and NPC in a Chinese population. We analyzed single nucleotide polymorphisms (SNPs) of IL‐12 gene 16974 A/C and IL‐27 gene ?964 A/G, 2905 T/G, 4730 T/C in 302 patients with NPC and 310 age‐ and sex‐matched controls, using polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) and DNA sequencing methods. There were significant differences in the genotype and allele distribution of 16974 A/C polymorphism of the IL‐12 gene among cases and controls. The 16974 CC and AC genotypes were associated with a significantly increased risk of NPC as compared with the 16974 AA genotypes (OR = 2.225, 95% CI 1.395–3.549, P = 0.001 and OR = 1.834, 95% CI 1.239–2.716, P = 0.002, respectively). The 16974 C allele was associated with a significantly increased risk of NPC as compared with the 16974 A allele (OR = 1.334, 95% CI 1.065–1.670, P = 0.012). However, genotype and allele frequencies of the IL‐27 gene ?964 A/G, 2905 T/G, 4730 T/C polymorphisms in NPC patients were not significantly different than that in healthy controls (P > 0.05). Our data suggest that IL‐12 gene may play a role in the development of NPC. © 2009 Wiley‐Liss, Inc.