砷诱导的肝癌细胞凋亡及端粒酶活性改变

Arsenic induced apoptosis and activity change of telomerase in hepatoma

目的 研究三氧化二砷 (As2 O3 )对肝癌细胞凋亡的诱导作用及其机制。方法 1 μmol LAs2 O3 处理培养的人肝癌HCC 92 0 4细胞 48h,用形态学观察、细胞超微结构分析和流式细胞仪检测等方法鉴定细胞凋亡。用噻唑蓝 (MTT)比色试验观察蛋白质合成抑制剂放线菌素D对As2 O3 凋亡诱导作用的影响。用TRAP PCR ELISA法检测As2 O3 处理前后肝癌细胞端粒酶活性的变化情况。结果 1 μmol LAs2 O3 作用 48h后 ,HCC 92 0 4细胞出现了典型的凋亡形态学改变和超微结构变化 ;流式细胞仪检测到大量Annexin 阳性、PI 阴性细胞 ;放线菌素D可明显拮抗As2 O3 的凋亡诱导作用。细胞凋亡发生后端粒酶活性显著降低 ,A450 A63 0 值从 2 874降为 0 767。结论 As2 O3 可以有效诱导肝癌细胞凋亡 ,端粒酶活性降低可能是其中的机制之一。

Objective To investigate the apoptosis induced by arsenic trioxide (As 2O 3) and its possible mechanism in hepatoma cells.Methods Cultured hepatoma HCC 9204 cells ware exposed to 1 μmol/L As 2O 3 for 48 h. Cell apoptosis was ascertained by morphological observation, electron microscopy and cytofluorimetric analysis. MTT assay was employed to detect the effect of actinomycin D on arsenic induced apoptosis. Activity of telomerase was measured by the method of TRAP PCR ELISA before and after treatment of As 2O 3. Results After HCC 9204 cells were treated with As 2O 3 at the dose of 1μmol/L As 2O 3 for 48 h,some classical morphological changes of apoptosis were observed under both phase contrast microscope and transmission electron microscope. The number of annexin positive and PI negative cells,which represented apoptosis, increased significantly after the treatment of As 2O 3. Apoptosis effect of As 2O 3 could be inhibited by actinomycin D significantly. The decrease of A 450 / A 630 value from 2 874 to 0 767 accounted for the reduction of activity for telomerase with the treatment of As 2O 3.Conclusion As 2O 3 was an effective apoptosis inducer of hepatoma, and this effect might be associated with the decrease of activity of telomerase.