皮肤鳞癌中E-钙粘素基因启动子甲基化状态的研究

The Study on Promoter Methylation Status of E-cadherin Gene in Cutaneous Squamous Cell Carcinoma

目的探讨E-cadherin基因甲基化在皮肤鳞状细胞癌(简称皮肤鳞癌,SCC)发病机制中的作用。方法采用甲基化特异性PCR(MSP)检测皮肤鳞癌和正常组织中E-cadherin基因CpG岛的甲基化状态,通过RT-PCR检测经不同浓度5′-氮杂胞苷处理以后的人表皮鳞癌细胞株A431E-cadherin mRNA表达的差异,MTT法观察5′-氮杂胞苷对细胞增殖的影响。结果皮肤鳞癌中E-cadherin基因CpG岛的甲基化率34.6%(9/26),正常皮肤组织中未发现E-cadherin基因甲基化状态,差异有显著性(P<0.05)。经5′-氮杂胞苷处理后A431肿瘤细胞E-cadherin的mRNA表达上调,有统计学意义(P<0.05)。5′-氮杂胞苷能抑制A431肿瘤细胞的增殖。结论E-cadherin基因可能通过CpG岛甲基化抑制基因转录,在皮肤鳞癌的发生、发展中发挥一定的作用。

Objective To explore the role of methylation of E-cadherin gene in the pathogenesis of cutaneous squamous cell carcinoma （SCC）. Methods E-cadherin gene methylation was studied using methylation specific polymerase chain reaction in paraffin-embedded tissues, And reverse-transcription polymerase chain reaction technique to analyze the mRNA expression of E-cadherin in A431 cell line treated with different concentration of 5＇-azacytidine, The impact of 5＇-azacytidine on the growth of A431 cell line, was observed with MTF. Results The CpG island methylation rate of E-cadherin gene was 34.6% in SCC （P 〈 0.05） , while no methylation of E-cadherin gene was found in normal skin tissues, There was statistically significant difference of E-cadherin expression between normal skin and SCC （P 〈 0.05 ）. The mRNA expression of E-cadherin was up-regulated after treated with 5＇-azaeytidine（P 〈0.05 ） in A431eell line. And methylation inhibitor 5＇-azaeytidine was demonstrated to inhibit the growth of A431 cell line. Conclusion The methylation of CpG island of E-eadherin gene might contribute to its inactive transcription and play a role in tumor development or progression in cutaneous squamous cell eareinoma（SCC）.