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目的研究组蛋白去乙酰化酶抑制剂曲古菌素A(trichostatin A,TSA)抑制HL-60细胞端粒酶活性及亚单位hTERT的表达并诱导凋亡的机制.方法采用MTT法和倒置相差显微镜观察不同浓度曲古菌素A对HL-60细胞的抑制作用,流式细胞仪检测600 nmol·L-1 TSA作用后的细胞凋亡情况,TRAP-ELISA法检测端粒酶活性变化,RT-PCR分析端粒酶三个亚单位的mRNA表达情况.结果 TSA对HL-60细胞的抑制作用具有时间和剂量依赖性,AnnexinV/PI双染色法检测凋亡显示,600 nmol·L-TSA作用48 h后,细胞凋亡率为42.6%.600 nmol·L-1TSA作用12、24和48 h后,端粒酶活性分别下降到1.95±0.25、1.73±0.12和1.52±0.09.RT-PCR显示,端粒酶逆转录酶hTERT表达下降,而端粒酶RNA模板(hTR)和端粒酶相关蛋白(hTP1)表达无明显改变.结论TSA抑制HL-60细胞中端粒酶活性,并诱导凋亡,其机制可能与曲古菌素A下调hTERT转录水平有关.“,”Aim To investigate the effects of trichostatin A (TSA) on telomerase activity and the expression of human telomerase reverse transcriptase (hTERT) during apoptosis in vitro and the mechanisms in HL-60 cells. Methods The proliferative activity of HL-60 cells was assessed by MTT assay.Cell apoptosis was analyzed by flow cytometry. Telomerase activity was examined by TRAP-ELISA. The expression of telomerase subunits was analyzed by RT-PCR. Results A time- and dose-dependent inhibition was detected in HL-60 cells treated with TSA. After treatment with 600 nmol· L-1 TSA for 48 h,the apoptosis rate in HL-60 cells was 42. 6% and telomerase activity decreased 1.95 ± 0. 25, 1.73 ± 0. 12, and 1.52 ± 0. 09 for 12, 24, and 48 h, respectively. The expression of hTERTmRNA de creased. No significant changes were observed in the expression of hTRmRNA and hTP1 mRNA. Conclusion TSA inhibits telomerase activity and induces apoptosis in HL-60 cells. The underlying mechanism may be related to the down-regulation of hTERT transcription.