RHPS4限制端粒重复序列结合因子2蛋白的端粒保护作用

Telomeric repeat binding factor 2 has no protective effect against RHPS4

目的 :探讨抗肿瘤药物RHPS4影响端粒重复序列结合因子2(TRF2)对端粒保护作用的机制。方法:在过表达TRF2的A375细胞体系中加入RHPS4,通过蛋白质印迹及免疫荧光结合共聚焦显微镜成像技术检测细胞DNA损伤情况,通过流式细胞技术及细胞增殖实验检测药物对细胞增殖的影响。结果 :在A375细胞中过表达外源性TRF2能抑制DNA损伤的修复,但过表达TRF2不能抑制RHPS4诱导端粒损伤,RHPS4诱导的细胞周期停滞和细胞衰老过表达不依赖于TRF2的表达量。结论:TRF2高水平表达不能拮抗RHPS4的致端粒损伤和细胞周期抑制的作用,肿瘤细胞中高表达TRF2不是应用RHPS4药物的反指征。

Objective To investigate whether overexpression of telomeric repeat binding factor 2（TRF2） can antago-nize the anti-tumor effect of RHPS4. Methods Cells of A375 cell line with over-expression of telomeric repeat binding factor 2（TRF2）were treated with RHPS4. DNA damages were detected by Western blotting and immunofluorescence con-focal microscopic imaging technique, and drug effects on cell proliferation were assessed by flow cytometry. Results Overexpression of exogenous TRF2 could inhibit the repair of DNA damage in A375 cells, but could not inhibit the RHPS4 in-duced telomere damage, cell cycle arrest and cell senescence. Conclusions These results indicated that cancers with up regulation of TRF2 is not a contradiction for RHPS4 treatment, since high expression of TRF2 did not counteract the telomeric damaging effect and cell arrest induced by RHPS4.