雷帕霉素对低氧下人HL-60细胞增殖和凋亡的影响

本研究拟通过小分子化合物氯化钴（CoCl2）模拟的低氧环境，探讨雷帕霉素（RPM）对该低氧下人急性髓细胞白血病HL-60细胞的生物学行为的影响。低氧模拟组、低氧雷帕霉素处理组、常氧雷帕霉素处理组HL-60细胞分别采用CoCl2、CoCl2／RPM、RPM进行处理，对照组为常氧下常规培养的HL-60细胞，处理及培养24h、48h、72h后收集细胞，采用倒置相差显微镜观察细胞生长状况，常规瑞氏染色后光学显微镜下观察细胞形态；MTT比色法检测各组细胞的活性和增殖能力；AnnexinV—FITC／PI双染法流式细胞术检测细胞凋亡。结果表明，与对照组细胞形态规则，胞核呈圆形或椭圆形相比，低氧模拟组和低氧雷帕霉素处理组细胞密度降低，生长明显受抑，细胞胞核呈不规则形或杆状，染色质粗糙，伴扭曲折叠等变化。各组间不同时问细胞增殖抑制率差异显著（P〈0．05），低氧模拟组和低氧雷帕霉素处理组增殖抑制率随着处理时间延长而增大，且低氧雷帕霉素处理组的增殖抑制率大于低氧模拟组。与常氧下的对照组及雷帕霉素处理组比较，低氧的模拟组和雷帕霉素处理组诱导细胞发生较明显的凋亡，且后期72h低氧雷帕霉素处理组凋亡率显著高于模拟低氧处理组。以上结果表明，模拟低氧环境下，HL-60细胞生长明显受抑制，且诱导细胞凋亡；雷帕霉素可增强对低氧对细胞的生长抑制和诱导凋亡作用。

The Study of Effects of Rapamycin on Human Acute Myeloid Leukemic HL-60 Cell Proliferation and Apoptosis under Hypoxia Environment

To explore the biological effects of rapamycin on human acute myeloid leukemic cell line HL-60 under mimic hypoxic environment,the mimic hypoxic group,RPM normoxic group and RPM hypoxic group were treated with CoCl₂、CoCl₂/RPM,RPM,respectively.The control group was treated with routin culture under nomal hypoxia environment. The cells were collected at 24 h,48 h,72 h after treatment for the following tests.The morphologic changes of cells were observed under inverted microscope and light microscope with Wright’ s stain.MTT assay was used to evaluate the proliferation of cells.Flow cytometer was used for cell appoptosis using Annexin V-FITC/PI kit.Compared to the control group,the cells showed distinguished morphological changes with indented,band-shaped,folded nucleus and pyknotic chromatin and the increased inhibition rate in both the mimic hypoxic group and RPM normoxic group.There was a significant differences of inhibition rate of cell proliferation between control group and the others group by MTT experiment （P < 0.05 ）.The inhibition rate of cell proliferation increased with the extension of the processing time in mimic hypoxic group and RPM hypoxic group.It was found that obvious cell apoptosis occurred in mimic hypoxic group and RPM hypoxic group and became greater with time.Comparing with the mimic hypoxic group,there was a marked increase of apoptosis rate in RPM hypoxic group at 72h after treatment.These results suggested that the growth of HL-60 cells was inhibited obviously and cells occurred apoptosis under the CoCl₂ mimic hypoxic condition and the effects might be enhanced by RPM.