TMS1/ASC基因启动子甲基化与卵巢癌发生的关系

Methylation of TMS1/ASC gene in promotor region is related with the genesis of ovarian carcinoma.

目的探讨TMS1/ASC(targetofmethylation-inducedsilencing)基因在卵巢癌细胞株及组织中的甲基化状态及该基因表达在卵巢癌发病机制中的作用。方法选取人卵巢癌细胞株A2780,SKOV3,Angle,CAOV3,OVCAR3,SW626,COC1,以及18例卵巢癌组织和10例正常卵巢组织作为研究对象,采用甲基化特异性PCR(MSP)检测卵巢癌细胞株以及卵巢癌组织中TMS1/ASC基因启动子区域甲基化的状态,用RT-PCR和WesternBlotting法分别检测其mRNA和蛋白的表达。用去甲基化药物5-氮-2'-脱氧胞苷(5-Aza-CdR)处理TMS1/ASC甲基化阳性细胞株并分析其mRNA和蛋白的表达的变化。结果4株卵巢癌细胞(A2780,SKOV3,Angle,SW626)和7例卵巢癌组织中检测出TMS1/ASC基因的异常甲基化。发生甲基化的细胞株TMS1/ASC基因的mRNA和蛋白表达较未发生甲基化的细胞株明显下降。10例正常卵巢组织中均未发现TMS1/ASC甲基化,差异有统计学意义(P<0·05)。用去甲基化药物5-Aza-CdR处理TMS1/ASC甲基化阳性细胞株SKOV3后,该细胞株中TMS1/ASC基因恢复表达。结论卵巢癌中存在TMS1/ASC基因甲基化,这可能是导致该基因沉默的重要原因,并在卵巢癌的发病机制中起作用。

Objective ：To investigate the correlation between methylation of TMS1/ASC gene in promotor region and the genesis of ovarian cancer. Methods： Genomic DNA was isolated from 7 ovarian cancer cell lines, 18 primary ovarian cancer specimens and 10 normal ovary specimens. Methylation-specific PCR was used to detect methylation of TMS1/ASC promotor region. Expression of TMS1/ASC was examined by RT-PCR and Western blotting. Results： Methylation of TMS1/ASC gene was observed in 4/7 ovarian cancer cell lines and 7/18 primary ovarian cancer tissues,but none in the 10 normal ovary specimens（P 〈 0.05）. The expression of TMS1/ASC gene in cancers with methylation was lower than that in cancers without methylation. TMS1/ASC gene expression was restored by treatment with the demethylating agent 5-aza- 2＇-deoxycitidine in the SKOV3 cell line, which lacks the TMS1/ASC transcript. Conclusions： Methylation of TMS1/ASC is a frequent event in ovarian cancer and is an important mechanism for the loss of the expression of this gene. Aberrant methylation of TMS1/ASC may play a role in the pathogenesis of ovarian cancer.