Promoter methylation and expression of fragile histidine triad gene gene in papillary thyroid carcinoma

Abstract

Objective To study the promoter methylation and expression of fragile histidine triad gene (FHIT) in papillary thyroid carcinoma (PTC).Methods Methylation-specific polymerase chain reaction (MSP) and Western blotting were used to detect the methylation of FHIT gene promoter and the protein expression in 60 cases of PTC and their matched adjacent non-carceious epithelium (NCE).Results In NCE,there was no methylation of FHIT gene promoter,while in PTC the hyper-methylation rate was 38.3％ (23/60),which was related to the tumor TNM stage,pathological grade and lymph node metastasis (P ＜ 0.05).The positive rate of FHIT protein expression in NCE and PTC was 100.0％ (60/60) and 41.7％ (25/60) respectively (P ＜0.05).In PTC,FHIT protein expression was related to the tumor TNM stage,pathological grade and lymph node metastasis (P ＜ 0.05).Moreover,there was a distinct correlation between methylation of FHIT gene promoter and the protein expression (P ＜ 0.05).Conclusion Methylation of promoter might be one of the important mechanisms of inactivation of FHIT gene,and might play an important role in carcinogenesis and progression of PTC. Key words: Papillary thyroid carcinoma; Fragile histidine triad gene; Methylation