目的： 观察PI3K/Akt/mTOR通路抑制剂wortmannin或rapamycin对白血病细胞株增殖及其PHLPP（PH domain leucine-rich repeat protein phosphatase）蛋白表达的影响。 方法： 以不同浓度的wortmannin或rapamycin分别作用于人类髓细胞白血病细胞系K562、HL-60，采用WST-1法检测细胞的增殖活性，Annexin Ⅴ-FITC双染流式细胞术检测细胞凋亡，Western blotting法检测细胞中p-Akt、Akt、PHLPP蛋白的表达。 结果： Wortmannin以时间以及剂量依赖方式抑制K562、HL-60细胞的增殖（P<0.05），48 h的IC50值分别为（187.6±48.4）、（185.5±48.1）nmol/L。100 nmol/L wortmannin作用于K562细胞、50 nmol/L wortmannin 作用于HL-60细胞12和24 h后，细胞凋亡率均较对照细胞显著升高\[（12.4±0.7）%、（17.6±2.3）% vs （5.0±0.6）%，P<0.05；（11.0±0.2）%、（17.9±1.6）% vs (6.8±0.4)%，P<005\]。Wortmannin分别作用于K562、HL-60细胞12、24、36 h后，p-Akt、PHLPP的蛋白表达水平明显降低；rapamycin同样可使K562、HL-60细胞中PHLPP蛋白的表达水平降低。 结论： PI3K/Akt/mTOR信号通路抑制剂抑制白血病细胞株增殖的同时降低其PHLPP蛋白的表达。

Objective: To observe the effect of PI3K/Akt/mTOR pathway inhibitors wortmannin or rapamycin on the proliferation and PHLPP (PH domain leucine-rich repeat protein phosphatase) protein expression of leukemia cell lines. Methods: Human leukemia cell lines K562 and HL-60 were treated with different concentrations of wortmannin or rapamycin. The proliferation of K562 and HL-60 cells was examined by WST-1 assay and the apoptosis of K562 and HL-60 cells was detected by Annexin Ⅴ-FITC double staining flow cytometry. The expressions of PHLPP, phosphorate-Akt (p-Akt) and total Akt protein were detected by Western blotting. Results: Wortmannin inhibited the proliferation of K562 and HL-60 cells in a dose- and time-dependent manner, with the IC50 value of 48 h being (187.6±48.4) nmol/L and (185.5±48.1) nmol/L (P<0.05). After treating K562 cells with 100 nmol/L wortmannin and HL-60 with 50 nmol/L wortmannin for 12 and 24 h, the apoptosis rates were significantly higher than those in the control group (\[12.4±0.7\]%, \[176±2.3\]% vs \[5.0±0.6\]%, P<0.05; \[11.0±0.2\]%, \[17.9±1.6\]% vs \[6.8±0.4\]%, P<0.05). After treating K562 and HL-60 cells with wortmannin for 12，24 and 36 h，the protein expressions of p-Akt and PHLPP were significantly reduced. And rapamycin also down-regulated the protein expression of PHLPP in K562 and HL-60 cells. Conclusion: The inhibitor of PI3K/Akt/mTOR signaling pathway inhibit the proliferation as well as PHLPP protein expression of leukemia cell lines.

辽宁省自然科学基金项目（No.20072105）