Yan Chao-Qi, Zhang Li-Jun
Department of Hematology, First Affiliated Hospital of China Medical University, Shenyang, China.
Zhongguo Shi Yan Xue Ye Xue Za Zhi. 2012 Aug;20(4):889-92.
This study was aimed to investigate the effect of AG490, a JAK2 inhibitor, on expression of PHLPP and p-Akt in K562. K562 cells were treated with different concentrations of AG490. The proliferation of K562 cells was examined by WST-1 assay and apoptosis of K562 cells was detected by flow cytometry with Annexin V-FITC/PI double staining. The expressions of PHLPP, phosphorate-Akt (p-Akt) and total Akt protein were detected by Western blot. The results indicated that AG490 inhibited the proliferation of K562 cells in concentration-and time-dependent manners, with the IC(50) 338.0 µmol/L in 48 h. AG490 100 µmol/L also induced apoptosis of K562 cells in a time-dependent manner. AG490 100 µmol/L time-dependently down-regulated the protein expression of p-Akt and PHLPP, but without significant effect on expression of total Akt. It is concluded that AG490 can inhibit proliferation and induce apoptosis of K562 cells through down-regulation of p-Akt expression, but inhibiting efficacy of AG490 on K562 proliferation also may be limited due to the down-regulation of p-Akt regulatory protein PHLPP expression.
本研究旨在探讨JAK2抑制剂AG490对K562细胞中PHLPP和p-Akt表达的影响。用不同浓度的AG490处理K562细胞。采用WST-1法检测K562细胞的增殖情况，用Annexin V-FITC/PI双染法通过流式细胞术检测K562细胞的凋亡情况。通过蛋白质免疫印迹法检测PHLPP、磷酸化Akt（p-Akt）和总Akt蛋白的表达。结果表明，AG490以浓度和时间依赖性方式抑制K562细胞的增殖，48小时时的IC(50)为338.0 µmol/L。100 µmol/L的AG490也以时间依赖性方式诱导K562细胞凋亡。100 µmol/L的AG490可时间依赖性地下调p-Akt和PHLPP的蛋白表达，但对总Akt的表达无显著影响。结论是，AG490可通过下调p-Akt表达抑制K562细胞的增殖并诱导其凋亡，但由于p-Akt调节蛋白PHLPP表达的下调，AG490对K562增殖的抑制作用可能也有限。
