The promoter methylation and expression of DKK3 gene in papillary thyroid carcinoma

Abstract

Objective To study the relationship between status of methylation of DKK3 gene promoter and expression of its mRNA in papillary thyroid carcinoma (PTC).Methods Methylation-specific PCR (MSP) and RTPCR were applied respectively to examine the methylation of DKK3 gene promoter and its mRNA expression in 49 samples of PTC and their matched adjacent non-cancerous epithelium(NCE).Results No case had methylation of DKK3 gene promoter for NCE.In PTC,the rate of methylation DKK3 gene promoter was 38.8％ (19/49),significantly higher than that in NCE(P ＜0.01).The positive expression rate of DKK3 gene mRNA was 100％ in NCE and 44.9％ (22/49) in PTC.The difference had statistical significance (P ＜ 0.01).In PTC,the hypermethylation of DKK3 gene and the expression of DKK3 mRNA had correlation with pathological grading,TNM stage,and lymph node metastasis (P ＜0.05).There was distinct correlation between methylation of DKK3 gene promoter and expression of its mRNA (P ＜0.01).Conclusion Methylation of the DKK3 promoter might be one of the mechanisms resulting in transcription silence,and might play an important role in carcinogenesis and progression of PTC. Key words: Papillary thyroid carcinoma; Methylation; DKK3; Wnt pathway