Jagged1调控STAT3信号通路影响多发性骨髓瘤细胞的生长和凋亡

目的:研究Jagged1对多发性骨髓瘤细胞生长和凋亡的影响及其机制。方法:多发性骨髓瘤细胞U266转染Jagged1小干扰RNA和小干扰RNA阴性对照,RT-q PCR和Western blot检测细胞中的Jagged1水平,以不做转染的细胞为空白对照,台盼蓝染色,绘制细胞生长曲线,MTT检测细胞活力,流式细胞术检测细胞凋亡,Western blot检测细胞中信号转导及转录激活因子3(STAT3)、磷酸化STAT3(p-STAT3)和Bax的蛋白表达水平。用STAT3信号通路抑制剂AG490处理细胞,检测细胞中p-STAT3水平。AG490处理下调Jagged1表达后的U266细胞,MTT检测细胞活力,流式细胞术检测细胞凋亡。结果:与空白对照组细胞相比,转染Jagged1小干扰RNA后细胞中Jagged1的mRNA和蛋白水平下降(P0.05),而转染小干扰RNA阴性对照的细胞中Jagged1的mRNA和蛋白水平没有变化。与不做转染的细胞相比,敲减Jagged1表达的U266细胞生长速度降低,细胞活力降低,细胞凋亡率升高(P0.05)。与不做转染的细胞相比,敲减Jagged1表达的U266细胞中Bax水平升高,p-STAT3水平下降(P0.05)。AG490处理后的U266细胞p-STAT3水平下降,STAT3信号通路激活受阻。AG490可以促进下调Jagged1诱导的U266细胞凋亡,抑制细胞活力。结论:敲减Jagged1表达通过抑制STAT3信号通路促进多发性骨髓瘤细胞凋亡,抑制细胞生长。

Jagged1 regulates STAT3 signaling pathway and affects growth and apoptosis of multiple myeloma cells

AIM:To investigate the effect of Jagged1 on the growth and apoptosis of multiple myeloma cells. METHODS:Transfection with small interfering RNA targeting Jagged1 and negative control was carried out in multiple myeloma cell line U266, and the mRNA and protein levels of Jagged1 in the cells were determined by RT-qPCR and Wes-tern blot. The cells without transfection were used as blank control. Trypan blue staining was used to draw the cell growth curve. The cell viability was measured by MTT assay. The apoptosis was analyzed by flow cytometry. The protein levels of STAT3, p-STAT3 and Bax in the cells were determined by Western blot. STAT3 signaling pathway inhibitor AG490 was used to detect the activation level of STAT3 signaling in the cells. RESULTS:Compared with the U266 cells without transfection, the expression of Jagged1 at mRNA and protein levels decreased in the U266 cells transfeced with small interfering RNA targeting Jagged1 (P<0.05). However, the expression of Jagged1 at mRNA and protein levels did not change in the U266 cells transfected with small interfering RNA negative control. Knockdown of Jagged1 expression decreased the cell viability, increased the apoptotic rate, increased Bax levels, and decreased the protein level of p-STAT3 in the U266 cells (P<0.05). AG490 treatment decreased the protein level of p-STAT3, blocked the activation of STAT3 signaling pathway, promoted the cell apoptosis induced by Jagged1 knockdown, and inhibited the viability of the U266 cells. CONCLUSION:Knock-down of Jagged1 expression promotes the apoptosis of multiple myeloma cells by inhibiting STAT3 signaling pathway, thus suppressing cell growth.