辛伐他汀联合阿糖胞苷对K562细胞增殖与凋亡的影响

 目的　探讨辛伐他汀（SV）联合阿糖胞苷（Ara-C）对K562 细胞增殖与凋亡的影响。方法　不同浓度SV和Ara-C单用或者联合处理K562细胞，对照组为K562细胞。药物作用24、48、72 h后收集细胞，分别观察各组细胞形态，采用MTT法检测不同组别细胞的生长抑制率，采用流式细胞术检测细胞早期凋亡率、细胞坏死比例。结果　SV联合Ara-C组与单药组相比细胞形态明显有核固缩现象，且可见凋亡小体形成，并且随着处理时间的增加，抑制率也增大。其中15 μmol／L SV联合20 μmol／L Ara-C的细胞抑制作用最为显著，72 h细胞抑制率为（72±1）%，明显高于15 μmol／L SV组的（45±2）%和20 μmol／L Ara-C组的（44±0）%（P＜0.01），表现为协同抑制作用（24、48 h金氏Q值为1.24和1.19）。流式细胞术检测发现20、15和 10 μmol／L SV组K562细胞早期凋亡率AnnexinV明显高于对照K562细胞（P＜0.01），而且随着时间延长和剂量的增大早期凋亡率也增加（P＜0.05）。20和15 μmol／L SV组早期凋亡率均高于10 μmol／L SV组，而前两者之间差异无统计学意义（P＞0.05）。晚期凋亡细胞率（PI）各组中差异均无统计学意义（P＞0.05）。结论　SV 体外抑制K562细胞增殖及诱导细胞凋亡，SV 与Ara-C具有协同作用，增加了K562细胞对化疗药物的敏感性。15 μmol／L 可能为SV体外最佳作用浓度。

Proliferative and apoptotic effects of simvastatin in combination with cytosine arabinoside on K562 cells

Objective To investigate the effect of simvastatin （SV） in combination with cytosine arabinoside （ARA-C） on the proliferation and apoptosis of K562 cells. Methods Human K562 cells were incubated with SV and cytosine arabinoside alone or in combination and K562 cells without any treatment were taken as normal control. Cells in different groups were collected at 24, 48 and 72 h after incubation for further detections. Morphological changes by Wright stain were performed. MTI＇ method was used to assay the growth inhibition rate and cytoflowmetry was used to detect the early stage apoptosis ratio and cell necrosis ratio. Results Compared with Ara-C group and SV group, cells in the group treated with SV combined with Ara-C showed obvious karyopyknosis,apoptosis bodies formation and significant cell growth inhibition, which were positively correlated with culture time. Combination of 15 μmol/L SV and Ara-C showed the most significant cell growth inhibition with a inhibition rate of （72±1） % at 72 h of culture, as was significantly higher than ihat of 15 μmol/L SV group （45±2） % and 20 μmol/L Ara-C group （44±0） % （P 〈0.01）, furthermore, combination of 15 μmol/L simvastatin and Ara-C showed synergistic inhibition with Q value of 1.24 and 1.19 at 24 h and 48 h in each. The apoptosis rates at early stage （AnnexinV） detected by flow cytometry in 20 txmol/L, 15 bLmol/L and 10 Ixmol/L SV treated K562 cells were significantly higher than that in normal K562 cells （P 〈0.01）, as were positively correlated with culture time and SV dose （P 〈0.05）. There were no significant difference of early apoptosis rate between the 20 bLmol/L SV and 15 μmol/L SV groups （P 〉0.05）, yet the very two were both higher than that of 10 μmol/L SV group （P 〈0.05）. There were no statistic differences of late apoptosis rate （PI） among different treated groups （P 〉0.05）. Conclusion SV inhibited K562 cell proliferation and induced cell apoptosis in vitro, and combination of SV and Ara-C exhibited obvious synergistic inhibition and apoptosis, which may increase the sensitivity of K562 cell to chemotherapy. SV at 15 μmol/L may be the best concentration for K562 cells in vitro.