Aims: Interleukin-1beta (IL-1beta) is a multifunctional cytokine that up-regulates the inflammatory response and participates in carcinogenesis, malignant transformation, tumour growth, invasion and metastasis. The IL-1B gene, encoding IL-1beta cytokine, contains several single nucleotide polymorphisms. Previous studies have shown that the polymorphisms of this gene may be associated with an increased risk of some cancers. However, no specific genetic risk factor for nasopharyngeal carcinoma (NPC) has been identified so far and there is no report of the IL-1B gene polymorphisms in relation to NPC. The aim of this study was to test whether the promoter polymorphisms in the IL-1B gene are associated with the risk of NPC.
Materials and methods: Two single nucleotide polymorphisms of IL-1B gene (-511C/T and -31T/C) in 113 patients with NPC and 144 age- and sex-matched controls in a Chinese population were analysed using a polymerase chain reaction-restriction fragment length polymorphism strategy.
Results: The IL-1B-31 and -511 loci were in highly linkage disequilibrium, and the -511T allele carriers were associated with a significantly increased risk of NPC as compared with the non-carriers (odds ratio=1.53, 95% confidence interval=1.07-2.17, P=0.018). Genotypes and allele frequencies at the IL-1B-31 locus in NPC cases were not different from the controls. Haplotype analysis showed that the -511T/-31T haplotype of the IL-1B gene conveyed the high risk for NPC compared with the -511C/-31T haplotype (odds ratio=17.09, 95% confidence interval=5.90-49.56, P<0.001).
Conclusion: This is the first report describing the association between IL-1B gene polymorphisms and NPC, and our data suggest that the IL-1B-511C/T polymorphism and the -511T/-31T haplotype may contribute to the risk of developing NPC in the Chinese population.