γ-射线诱导HL-60细胞凋亡的观察

Observation of γ-irradiationinduced apoptosis on HL-60 cells

目的 观察γ-射线诱导HL-60细胞凋亡的时间和剂量效应，以探求辐射诱发肿瘤细胞凋亡分子机制。方法 分别以2.5、5、7.5、10、15Gy γ射线照射HL60细胞，于照后继续培养3、6、9、12、24、27、30h，分别收获细胞。电泳检测DNA梯状带；流式细胞术(FCM)细胞凋亡定量并观察细胞周期变化；Hoechst 33258-PI复染荧光显微镜计数凋亡细胞及已死亡细胞百分率。结果 HL-60细胞受照后死亡方式主要是凋亡，其首先阻滞在G２／M期并由此走向凋亡；DNA梯状带及FCM检测结果发现，细胞凋亡具有时间和剂量依赖性；Hoechst 33258PI染色法检测结果与FCM检测的凋亡细胞随剂量的加大及时间的推移而增多的结果并不呈平行关系。结论 γ-射线诱导HL-60细胞凋亡时间和剂量效应关系的确立为进一步探讨该凋亡途径分子机制奠定了基础。

Objective To study time and dose effects of γ-r adiationinduced apoptosis in HL60 cells for finding out the mechanisms of ra di ationinduced apoptosis of human tumors.Methods HL60 cells w ere exposed in γradiation of 2.5,5,7.5,10,15Gy and incubated for 3,6,9,12,24, 27,30h. Apoptosis was measured by using gel electrophoresis for DNA ladder, FCM for apoptotic analysis and cell cycle distribution, and Hoechst 33258PI fluore scent staining for the percentage of apoptotic and died cells.Results The predominant model of cell death in HL60 after irradiation was apoptos is . These HL-60 cells were arrested in G2/M,suggesting that apoptosi s of HL-60 occurred during G2/M. The apoptosis was increased with the dose an d time after radiation based on DNA ladder and FCM analy sis. The results of the percent apoptosis by Hoechst 33258PI staining did not parallel that by FCM. Conclusion The determination of time and dose effects of γradiationinduced apoptosis in HL60 cells lays the fou ndation to study molecular mechanism of the apoptotic processes.