天花粉蛋白对宫颈癌Caski细胞DNMT1基因的表达和酶活性的影响

目的研究天花粉蛋白(trichosanthin,TCS)对宫颈癌Caski细胞DNMT1基因的表达和酶活性的影响,并探讨天花粉蛋白抗宫颈癌及去甲基化机制,寻找新型去甲基化药物。方法应用RT-PCR、实时荧光定量PCR和Western免疫印迹分析检测天花粉蛋白对宫颈癌Caski细胞DNMTI基因表达的影响;应用DNMT1酶活性试剂盒检测天花粉蛋白对DNMT1酶活性的影响。结果经天花粉蛋白处理后,Caski细胞中DNM1基因mRNA及蛋白表达水平降低,体外酶活性分析发现,TCS对DNMT1酶活性有直接抑制作用。结论天花粉蛋白去甲基化的作用可能是通过抑制DNMTs的活性而实现的;天花粉蛋白有可能是新型的DNMTs抑制剂,具有潜在的临床应用价值。

The effect of trichosanthin on the expression and enzyme activity of DNMT1 gene in Caski cervical cancer cell line

Aim To study the effect of trichosanthin(TCS) on the expression and enzyme activity of DNMT1 gene in Caski cervical cancer cell line,and to investigate the underlying mechanism of TCS as an anticervical-cancer agent and a demethylation drug.Methods RT-PCR,real-time PCR and Western blot assay were used to detect expression of DNMT1 gene in Caski cell line after TCS treatment.The enzyme activity of DNMT1 was detected by DNMT1 Activity Screening Assay Kit.Results After TCS treatment,the expression of DNM1 in mRNA and protein levels were decreased significantly.Analysis in vitro showed that TCS also had a direct inhibition of DNMT1 enzyme activity. Conclusion The role of TCS in demethylation may be achieved by inhibiting DNMTs activity and TCS is a new type of DNMTs inhibitor with potential clinical value.