AG490下调STAT3活化增强葫芦素B对B16F10黑素瘤细胞的抑制作用

Down-regulation of STAT3 activation by AG490 enhances the inhibitory effects of cucurbitacin B on B16F10 melanoma cells

目的:研究Jak2/STAT3特异性抑制剂AG490对葫芦素B(CuB)抑制B16F10黑素瘤细胞效应的影响,并探讨其作用机制。方法:用MTS法检测细胞增殖状态;用碘化丙锭(PI)染色分析细胞凋亡和细胞周期分布;用免疫印迹检测p-STAT3以及STAT3蛋白的表达情况。结果:CuB以时间与浓度依赖方式抑制B16F10黑素瘤细胞的生长,AG490预处理能增强CuB对B16F10细胞的抑制作用;PI染色分析显示,AG490能增强CuB诱导B16F10细胞凋亡的比率;免疫印迹检测表明,CuB引起B16F10细胞中STAT3的活化(p-STAT3),AG490能明显下调p-STAT3蛋白的表达水平。结论:阻断Jak/STAT3的活化可增强CuB对B16F10黑素瘤细胞的抑制作用。

Aim： To study the effects of Janus kinase 2 （Jak2）/STAT3 specific inhibitor, AG490, onmouse B16F10 melanoma cells treated with cucurbitacin B （CuB）, and to explore the underlying mecha-nism. Methods： The proliferation of B16F10 melanoma cells was detected l^y MTS assay. Propidium io-dide （PI） staining was used to examine cell cycle distribution and apoptosis. Expression of p-STA33 andSTAT3 protein were detected by western blotting. Results： CuB could inhibit the proliferation of B16F10cells in a time- and dose-dependent manner. Pretreatment with AG490 enhanced the inhibitory effect ofCuB on the cells. PI staining analysis showed that AG490 could promote the proportion of apoptosis cellsin B16FIO cells treated with CuB. Western blotting analysis revealed that CuB induced the activation ofSTAT3 （p-STAT3） and AG490 suppressed the express level of p-STAT3 protein in CuB-treated cells.Conclusion：Blocking Jak2/STAT3 pathway could enhance the inhibitory effects of CuB on B16F10 mela-noma cells.