SALL3甲基化与宫颈癌的相关性

目的 检测正常宫颈组织、宫颈癌组织及宫颈癌细胞系中SALL3基因启动子区的甲基化状态,探讨其甲基化状态与SALL3基因表达的关系。方法 采用甲基化特异性PCR(MS-PCR)分析正常宫颈、宫颈癌组织及宫颈癌细胞系中SALL3基因启动子区DNA的甲基化状态,RT-PCR检测宫颈癌细胞系、宫颈癌组织及正常宫颈组织中SALL3基因mRNA表达。 结果 宫颈癌和癌旁组织中的SALL3基因启动子区甲基化水平分别为0.60(IQR:0.73,秩均值:16.70)(P=0.046)和0.82(IQR:0.50,秩均值:17.15)(P=0.039),均显著高于正常宫颈组织的0.03(IQR:0.39,秩均值:8.44)。宫颈癌及癌旁组织中SALL3蛋白的表达分别为0.10(IQR:0.17,秩均值:8.40)(P=0.012)和0.26(IQR:0.21,秩均值:15.6)(P=0.000),均显著低于正常宫颈组织的0.57(IQR:0.73,秩均值:20.75)。给予0、5、10 μmol/L 5-Azacytidine去甲基化处理HeLa及SiHa细胞后,HeLa(F=28.704,P=0.001)和SiHa细胞(F=29.783,P=0.002)中SALL3 mRNA的表达水平均随5-Azacytidine作用浓度的升高而升高。与高危型人乳头瘤病毒(HPV)阳性组织相比,HPV阴性宫颈组织中SALL3基因启动子区的甲基化水平明显降低(P=0.014),蛋白表达水平明显升高(P=0.021)。结论 宫颈癌组织中SALL3基因启动子区的DNA高甲基化使其表达沉默,高危型HPV感染可能通过增加SALL3启动子区甲基化使其沉默促进宫颈癌的发生。

Correlation between Methylation of SALL3 and Cervical Cancer

Objective To detect the methylation status of SALL3 gene promoter region in normal cervical tissues,cervical cancer tissues,and cervical cancer cell lines and thus explore the relationship between methylation status and the expression of SALL3 gene.Methods The DNA methylation statuses of SALL3 gene in normal cervical,cervical cancer tissues and cervical cancer cell lines were analyzed by methylation-specific PCR(MS-PCR).The expressions of SALL3 mRNA in cervical cancer cell lines,cervical cancer tissues,and normal cervical tissues were detected by RT-PCR.Results In cervical cancer and matched peri-carcinomatous samples,the methylation levels of SALL3 were up-regulated(CCa vs.CCap:P=0.046;CCa vs.NC P=0.039)and the protein expressions were down-regulated(CCa vs.CCap:P=0.012;CCa vs.NC P=0.000)when compared with normal cervix samples.The mRNA levels of SALL3 in HeLa and SiHa cells treated with 5-Azacytidine were elevated in a dose-dependent manner(HeLa:P=0.001;SiHa:P=0.002).The methylation level of SALL3 was higher in high risk human papillomavirus(HPV)-positive cervical samples than in HPV-negative cervical samples(P=0.014),which also resulted in a descending SALL3 expression in HPV-positive samples(P=0.021).Conclusions The hypermethylation of SALL3 in promoter regions inhibits the expression of SALL3 in cervical cancer tissue samples.Infection with high-risk HPV serotypes may increase the methylation of SALL3 promoter region,silence its expression,and thus promote the development of cervical cancer.