胰腺癌中人RUNT相关转录因子3基因启动子区甲基化及其临床意义

Promoter methylation of human RUNT-related transcription factor 3 gene in pancreatic carcinoma and its clinical significance

目的检测胰腺癌人RUNT相关转录因子3(RUNX3)基因启动子的甲基化情况并探讨其临床意义。方法采用甲基化特异性聚合酶链式反应(MSP)检测56例胰腺癌组织及癌旁组织、14例正常胰腺组织、3株人胰腺癌细胞株(PANC1、CFPAC-1、SW1990)、1株正常肝细胞株(HL-7702)中RUNX3基因启动子区CpG岛甲基化状态。检测用甲基化抑制剂5-氮杂-2'-脱氧胞苷(5-Aza-cdR)处理前后胰腺癌细胞株RUNX3 mRNA的表达。分析RUNX3异常甲基化与胰腺癌临床特征的关系。结果56例胰腺癌组织中,51.79%(29/56)存在RUNX3基因启动子区CpG岛的异常甲基化,癌旁胰腺组织有10.7%(6/56)存在异常甲基化,而正常胰腺组织中未检测到RUNX3基因异常甲基化。RUNX3基因异常甲基化与患者病理分化程度(r=0.314,P=0.018)、淋巴结转移(r=0.370,P=0.005)显著相关。在5-Aza-cdR处理前,胰腺癌细胞株PANC1、CFPAC-1、SW1990的RUNX3 mRNA无表达或低表达,经5-Aza-cdR处理后各胰腺癌细胞株RUNX3 mRNA恢复表达。结论胰腺癌组织及胰腺癌细胞株均存在RUNX3基因CpG岛异常甲基化;RUNX3启动子的高甲基化与其基因表达降低有关,与胰腺癌组织分化程度、淋巴结转移相关。

Objective To detect the promoter methylation of human RUNT-related transcription factor 3 （RUNX3） gene in pancreatic carcinoma, and explore its clinical significance. Methods The methylation of promoter CpG island of 14 samples of normal pancreatic tissues, 56 samples of pancreatic carcinoma and adjacent tissues, 3 strains of pancreatic carcinoma cell lines （PANC1, CFPAC-1 and SW1990） and one strain of normal liver cell line （HL-7702） was detected by methylation-specific polymerase chain reaction （MSP） . The expression of RUNX3 mRNA in pancreatic carcinoma cell lines before and after treatment with methylation inhibitor 5-Aza-2deoxycytidine （5-Aza-cdR） was detected. The relationship between abnormal promoter methylation of RUNX3 gene and clinical characteristics of pancreatic carcinoma was analysed. Results Abnormal CpG island methylation in RUNX3 gene promoter was found in 29 cases of pancreatic carcinoma （29/56, 51.79% ） and 6 cases of adjacent tissues （6/56, 10.71% ）, while no abnormal CpG island methylation of RUNX3 gene was found in normal pancreatic tissues. Abnormal CpG island methylation of RUNX3 gene was significantly related to differentiation grade （r =0. 314, P =0. 018） and lymph node metastasis （r =0. 370, P =0. 005）. There was no expression or low expression of RUNX3 mRNA in pancreatic carcinoma cell lines （PANC1, CFPAC-1 and SW1990） before treatment with 5-Aza-cdR, while there was expression of RUNX3 mRNA in pancreatic carcinoma cell lines after treatment with 5-Aza- cdR. Conclusion Abnormal CpG island methylation of RUNX3 gene is found in pancreatic carcinoma tissues and pancreatic carcinoma cell lines. Promoter hypermethylation of RUNX3 is an important mechanism for low expression of RUNX3 in pancreatic carcinoma, and is significantly related to the differentiation grade and node metastasis.