目的：探讨二甲双胍对急性早幼粒细胞白血病（acute promyelocytic leukemia, APL）NB4细胞增殖与凋亡的影响及其可能的机制。方法：二甲双胍单独或联合多柔比星处理NB4细胞后，采用MTT法检测NB4细胞的增殖，采用流式细胞术检测细胞的凋亡，采用Western blotting法检测凋亡相关蛋白caspase-9及caspase-3的活化。结果：二甲双胍可剂量（r=0952，P<0.01）和时间（r=0.967，P<0.01）依赖性抑制NB4细胞的增殖，处理72 h后，其对NB4细胞的IC50值为（6.39±037）mmol/L。二甲双胍可增加NB4细胞对多柔比星的化疗敏感性，0.625 mmol/L二甲双胍联合0.02 μmol/L的多柔比星对NB4细胞的增殖抑制率明显高于单用多柔比星组\[（29.84±0.21）% vs （10.68±0.45）%，P<0.05\]。5 mmol/L二甲双胍处理48 h后，NB4细胞的凋亡率明显高于未处理对照组\[（43.95±0.29）% vs （7.12±0.29）%，P<0.01\]；二甲双胍处理NB4细胞后，凋亡蛋白caspase-3、caspase-9活化片段表达上调。结论：二甲双胍能够有效抑制APL细胞株NB4的增殖、促进其凋亡，并能增强其对多柔比星的化疗敏感性，caspase-3和caspese-9凋亡蛋白可能参与二甲双胍诱导NB4细胞凋亡的过程。

Objective:To investigate the effect of metformin on the proliferation and apoptosis of acute promyelocytic leukemia (APL) NB4 cells and the possible mechanism. Methods: After the treatment of metformin alone or in combination with daunorubicin, MTT assay and flow cytometry were used to detect the proliferation and apoptosis of NB4 cells, respectively. The activation of apoptosis-related proteins caspase-3 and caspase-9 was determined by Western blotting. Results: Metformin inhibited proliferation of NB4 cells in a dose-dependent (r=0.952, P<0.01) and time-dependent (r=0.967, P<0.01) manner. After metformin treatment for 72 h, its IC50 value to NB4 cells was (6.39±0.37) mmol/L. Metformin increased the chemosensitivity of NB4 cells to daunorubicin. The inhibitory rate of NB4 cell proliferation in 0.625 mmol/L metformin and 0.02 μmol/L daunorubicin combination group was significantly higher than that in daunorubicin used alone group (\[29.84±0.21\]% vs \[10.68±0.45\]%, P<0.05). After the treatment of 5 mmol/L metformin for 48 h, the apoptotic rate of NB4 cells was significantly increased compared with that of the control group (\[43.95±0.29\]% vs \[7.12±0.29\]%，P<0.01). The expressions of activated caspase-3 and caspase-9 fragments were up-regulated after metformin treatment.Conclusion: Metformin can efficiently inhibit the proliferation, promote the apoptosis of NB4 cells, and enhance the chemosensitivity of NB4 cells to daunorubicin. Caspase-3 and caspase-9 may be involved in the NB4 cell apoptosis induced by metformin.

国家自然科学基金资助项目（No. 81101786），江苏省“六大人才高峰”基金资助项目(No. 2011-ws-062)