The aim of this study was to investigate the association between a potentially functional polymorphism (rs153109, -964A > G) in the promoter region of interleukin-27 (IL-27) gene and the risk of papillary thyroid cancer (PTC) in a Chinese population. Genotype of IL-27 -964A > G polymorphism was determined using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Serum IL-27p28 levels were determined using enzyme-linked immunosorbent assay (ELISA). No significant difference was noticed in IL-27 -964A > G polymorphism between PTC patients and healthy controls in the overall analysis. However, analysis of clinical features showed that PTC patients carrying the GG genotype or G allele had significantly decreased risks for developing lymph node metastasis compared with those carrying the AA genotype or A allele (GG vs. AA: OR = 0.38, 95 % CI, 0.20-0.72; G vs. A: OR = 0.63, 95 % CI, 0.44-0.86). Furthermore, ELISA results demonstrated that serum IL-27p28 levels were significantly decreased in PTC patients compared with those in controls (P < 0.05). Serum IL-27p28 levels in healthy controls with the GG genotype were significantly high compared with those carrying AA genotype or the AG genotype (P < 0.05). In conclusion, our results suggest that IL-27 -964A > G polymorphism may be associated with the decreased risk for lymph node metastasis of PTC.
Keywords: IL-27; Papillary thyroid cancer; Polymorphism; Risk.