摘要
目的研究膀胱癌细胞T24中死亡相关蛋白激酶(DAPK)启动子区的甲基化状态,探讨使用5-杂氮脱氧胞苷(5-aza-dc)处理T24细胞后对DAPK转录表达的影响及其细胞生物学效应。方法使用不同浓度去甲基化药物5-aza-dc处理膀胱癌细胞株T24后,使用MTT法、流式细胞仪分别检测5-aza-dc对T24细胞的增殖抑制作用及凋亡率。应用甲基化特异性PCR(MSP)方法分别检测5-aza-dc(12.5μmol/L)处理前后T24细胞中DAPK启动子区甲基化状态的变化情况。应用RT-PCR、Western-blotting分别检测5-aza-dc(12.5μmol/L)处理前后T24细胞中DAPK转录、表达的变化情况。结果MTT法显示不同浓度5-aza-dc对T24细胞有明显的增殖抑制作用,流式细胞仪检测T24细胞的最大凋亡率为(24.12±1.4)%。正常培养条件下T24细胞中DAPK启动子区出现高甲基化且DAPKmRNA无表达,在5-aza-dc(12.5μmol/L)作用24h后,T24细胞中DAPK启动子区恢复为未甲基化状态且DAPKmRNA及蛋白重新恢复表达。结论膀胱癌细胞株T24中DAPK启动子区高甲基化可能是抑制其转录表达的重要原因;5-aza-dc可以通过去甲基化作用使DAPK恢复表达,从而抑制T24细胞的增殖并诱导细胞凋亡。5-aza-dc有望成为膀胱癌化疗的有效药物。
Objective To investigate the methylation status of the promoter of resion death associated protein kinase （DAPK） gene in bladder cancer cell （T24）, and study the effect of 5-aza-2＇-deoxycytidine （5-aza-dc） on DAPK gene reactive expression in T24 and its inhibitory effect on T24. Methods The bladder cancer cell T24 was treated with different doses of 5-aza-dc. The inhibitory effect and apoptosis rate were detected by MTT and flow cytometry, and the changes of DAPK mRNA and protein expression and the methylation status of DAPK promoter were assessed by RT-PCR, Western blotting, and methylation specific PCR, respectively. Results The growth of bladder cancer cell was inhibited significantly and the maximal apoptosis rate detected by flow cytometry was （24.12± 1.4）%. DAPK mRNA was not expressed in bladder cancer cell T24 in normal conditions. DAPK mRNA and protein re-expressed after 5-aza-dc （12.5 μmol/L） treatment in cell line T24 for 24 h, and DAPK promoter became unmethylated. Conclusions The promoter methylation can be an important factor for silencing the expression of DAPK in bladder cancer cell. 5-aza-dc can inhibit the growth and induce apoptosis of bladder cancer cells through reversing unmethylation status of DAPK promoter.
出处
《南方医科大学学报》
CAS
CSCD
北大核心
2009年第9期1882-1886,共5页
Journal of Southern Medical University
