Janus激酶抑制剂AG490对人视网膜母细胞瘤HXO-RB_(44)细胞JAK2/STAT3信号通路的影响

Effect of AG490 on JAK2/STAT3 signaling pathway in human retinoblastoma HXO-RB_(44) cell lines

目的:研究Janus激酶(Janus kinase,JAK)抑制剂AG490对人视网膜母细胞瘤HXO-RB44细胞株体外抗增殖及细胞周期的作用,探讨其对JAK2/信号转导与转录激活因子3(signal transducer and activator of transcription 3,STAT3)信号通路蛋白表达的影响。方法:本实验分为实验组和对照组,实验组又根据不同浓度(6.25,12.50,25.00,50.00,100.00,200.00μmol/L)的AG490处理分为6个不同浓度的实验组。采用细胞的活力测定法检测各组细胞增殖状态。应用流式细胞术对各组中细胞凋亡及周期进行分析。采用Western印迹检测处理后STAT3,p-STAT3及血管内皮生长因子(vascular endothelial growth factor,VEGF)蛋白的表达。结果:AG490处理HXO-RB44细胞株48 h后,随着药物浓度的增加,细胞抑制率增加,细胞存活率下降(均P<0.05)。除6.25μmol/L实验组外,其余5组与对照组两两比较,差异均有统计学意义(均P<0.05)。流式细胞术显示:随着AG490药物浓度的增加,细胞凋亡率呈逐渐增高趋势,与对照组相比,差异均有统计学意义(均P<0.05)。其中,50.00和100.00μmol/L实验组G1期细胞比例显著增多,相应地处于S期的细胞比例减少。Western印迹显示:随着AG490药物浓度的增加,STAT3和p-STAT3蛋白的表达量逐渐下降,与对照组相比,差异均有统计学意义(均P<0.05);VEGF表达量逐渐下降,与对照组相比,6.25和12.50μmol/L实验组的VEGF差异均无统计学意义(均P>0.05),其余各实验组差异均有统计学意义(均P<0.05)。结论:JAK抑制剂AG490能抑制HXORB44细胞株生长及增殖,促进细胞的凋亡增加;并通过阻断JAK2/STAT3信号通路而下调STAT3,p-STAT3和VEGF的表达,从而抑制HXO-RB44细胞株的增殖,加速其凋亡。

Objective： To investigate the role of Janus kinase （JAK） inhibitor AG490 in the anti-proliferation and cell cycle in human retinoblastoma HXO-RB44 cell lines in vitro, and to explore its eff ect on the expression of JAK2/signal transducer and activator of transcription 3 （STAT3）.Methods： Cells were divided into an experiment group and a control group, and the experiment group was further divided into 6 sub-groups according to different AG490 concentrations （6.25,12.50, 25.00, 50.00 or 100.00 μmol/L）. Cell proliferation in the different groups was analyzed by cell vitality determination. Cell cycle distribution and apoptosis rate were examined by flow cytometry. The protein levels of STAT3, p-STAT3 and vascular endothelial growth factor （VEGF） were detected by Western blot. Results： After 48 h treatment with AG490, the viability of HXO-RB44 cells was reduced in a concentration-dependent manner. Compared with the control group, there was no significant difference in the experiment groups except the 6.25 μmol/L group （all P〉0.05）. The apoptosis rates in the experiment groups were significantly increased with increase in concentration of AG490 compared with that in the control group （all P〈0.05）. The cell ratio in the G1 phase in 50 or 100 μmol/L group was increased, whereas the cell ratio in the S phase was decreased. Western blot results showed that the expressions of STAT3 and p-STAT3 in the experiment groups were dramatically reduced with the increase in concentration of AG490 compared with that in the control group （all P〈0.05）. VEGF expression didn’t obviously change in the experiment groups with AG490 concentration less than 12.5 μmol/L compared with that in the control group （both P〉0.05）, but there were significant differences in the other experiment groups （all P〈0.05）.Conclusion： JAK inhibitor AG490 can inhibit proliferation and promote apoptosis of the retinoblastoma HXO-RB44 cells through down-regulation of JAK2/STAT3 signaling pathway.