Association of Interleukin-10 (IL10) Promoter Genotypes with Nasopharyngeal Carcinoma Risk in Taiwan

Nasopharyngeal carcinoma (NPC) is a multifactorial type of cancer, and cytokines driving the immune response seem to be disturbed in patients with NPC. Interleukin-10 (IL10) is an immunosuppressive cytokine which may facilitate carcino genesis by down-regulating interferon-gamma production and supporting tumor escape from the immune response. We propose that differential expression levels of IL10 among individuals due to polymorphisms within the promoter of IL-10 gene, may be associated with NPC susceptibility. Therefore, the current study aimed at investigating the association of IL10 promoter genotypes with NPC and examining the interaction among the IL10 genotype and individual smoking habit in NPC susceptibility in Taiwan. A total of 698 native Taiwanese consisting of 176 cases and 522 controls were enrolled in this hospital-based study, and three single-nucleotide polymorphism sites at promoter regions of IL10, A-1082G (rs1800896), T-819C (rs3021097), and A-592C (rs1800872) were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and their interaction with smoking habit for NPC risk were evaluated. There were significantly different distributions of genotypic (p=0.0004) and allelic (p=0.0222) frequencies of IL10 A-1082G among NPC and controls. Individuals who carried AG or GG genotypes for IL10 A-1082G had a 1.91- and 3.26-fold higher risk of developing NPC compared to those who carried the AA genotype (95% confidence interval=1.28-2.85 and 1.35-7.85), respectively. None of the other polymorphisms investigated appeared to affect NPC risk. In gene-lifestyle interaction analysis, we have provided the first evidence ever to show that there is an obvious joint effect of IL10 A-1082G genotype with individual smoking habit on NPC risk. The results support the concept that interleukins may play a role in NPC development and that IL10 A-1082G, which is closely related to its protein expression, maybe a useful biomarker for NPC progression.