Bcl-xL和Caspase3在人卵巢癌细胞株凋亡过程中的调节作用

Regulatory Effect of Bcl-xL and Caspase3 in the Process of Apoptosis of Human Ovarian Cancer

目的 探讨 Bcl- x L和 Caspase3基因在顺铂诱导人卵巢癌细胞株凋亡过程中的表达及其在肿瘤细胞凋亡中的作用。方法 应用流式细胞术 ,RT- PCR技术和原位杂交技术 ,分别对顺铂诱导人卵巢癌敏感细胞株 (COC1)及卵巢癌耐药细胞株 (COC1/ DDP)的细胞凋亡及其 Bcl- x L和 Caspase3表达进行研究。结果 1不同顺铂浓度 (3、 6、 9.9μg/m l)作用下 COC1和 COC1/ DDP细胞凋亡率不同 ,COC1/ DDP细胞明显低于 COC1(P<0 .0 5 )。 2 COC1和 COC1/ DDP细胞株中均有 Bcl- x L基因表达 ,但 COC1/ DDP表达明显强于 COC1。在 6μg/ m l顺铂作用下 COC1和 COC1/ DDP细胞株中 Bcl- x L基因表达下调 ,以 COC1下降更明显。3原位杂交结果 ,6μg/ m l顺铂作用后 COC1和 COC1/ DDP细胞 Cas-pase3呈阳性 ,可见到凋亡细胞特征性形态学变化。结论 凋亡抑制基因 Bcl- x L在人卵巢癌多药耐药细胞株 (COC1/DDP)中高表达 ,是导致其细胞凋亡受抑制和对药物敏感性降低的重要原因 ,Caspase3在顺铂诱导凋亡的过程中被激活 。

Objective To investigate the expression and machanism of Bcl xL and Caspase3 in ovarian cancer apoptosis induced by cisplatin. Methods The expression of Bcl xL and Caspase3 genes was detected by using semi quantitative reverse transcription polymerase chain reaction (RT PCR) and in situ hybridization respectively following COC1 and COC1/DDP cells exposure to cisplatin of 6 μg/ml. Apoptosis following COC1 and COC1/DDP cells exposue to various doses of cisplatin (3 μg/ml, 6 μg/ml, 9.9 μg/ml) was detected by flow cytometry. Results Flow cytometry showed different apoptotic rate in COC1 and COC1/DDP cells. As compared to that of COC1 cells, apoptosis of COC1/DDP cells was apparently inhibited ( P <0.05). RT PCR showed the expression level of Bcl xL genes in COC1/DDP cells was higher than in COC1 cells. After exposure to cisplatin, the expression of Bcl xL in COC1 cells and COC1/DDP cells was down regulated. Hybridization in situ showed COC1 cells and COC1/DDP cells were positive for the Caspase3 with brownish yellow color in the cytoplasm after exposure to cisplatin of 6 μg/ml. The typical morphology of apoptotic cells was seen. Conclusion Cisplatin could induce the apoptosis of ovarian cancer cells, and the over expression of Bcl xL genes may contribute to the decreased susceptibility of cells to apoptosis and the development of multidrug resistance of human ovarian cancer. Caspase3 was activated during the course of apoptosis and facilitating the process of apoptosis.