熊果酸对多发性骨髓瘤细胞株U266的凋亡作用及机制

目的 探讨三萜类化合物熊果酸（ursoIic acid,UA）对多发性骨髓瘤（multiple myeloma,MM）细胞株U266的凋亡诱导作用及分子机制.方法 用熊果酸处理U266细胞,Cell Counting Kit-8法检测细胞增殖抑制情况;用20μmol/L熊果酸处理U266细胞24 h,瑞氏法染色后在光学显微镜下观察细胞凋亡的形态学变化;Annexin-V标记,在流式细胞仪上检测细胞凋亡率变化;用实时荧光定量PCR方法及Western blot方法检测FGFR3、Bcl-2、CCND1、MYC及p53的表达变化.结果 经熊果酸处理后,U266细胞的增殖受到抑制,光学显微镜下可观察到细胞形态不规则样改变,胞膜小泡状形成,细胞质内空泡增多,细胞核染色质浓缩、固缩;流式细胞术检测Annexin-V阳性细胞比例随用药浓度增加及用药时间延长而增加;细胞内FGFR3、Bcl-2、CCND1、MYC的mRNA和蛋白质表达随用药浓度增加及用药时间延长呈显著下降趋势,而p53的mRNA及蛋白表达逐渐增高.结论 熊果酸可抑制U266细胞的增殖并诱导其凋亡,体外有抗多发性骨髓瘤细胞作用,为多发性骨髓瘤选择新的靶向治疗方案提供实验依据.

Role of ursolic acid in inducing apoptosis of multiple myeloma U266 cells and its mechanism

Objective To study the role of ursolic acid （UA） in inducing apoptosis of multiple myeloma U266 cells and its molecular mechanism. Methods U266 cells were treated with UA. The inhibitory effect of UA on proliferation of U266 cells was detected by cell counting kit-8 test. The morphology of Annexin- V marked U266 cells was observed under optical microscope with Wright＇s staining. The apoptosis of U266 cells was detected by flow cytometry. The expressions of FGFR3, BCL2, MYC, CCND1 and P53 were detected by RT-PCR and Western blot, respectively. Results UA inhibited the proliferation of U266 cells. Optical microscopy showed that the morphology of U266 cells was irregular with formation of small vesicular membrane, vacuolization in cytoplasm, concentration and pyknosis of nucleus chromatin. Flow cytometry displayed that the number of Annexin- V positive cells increased, the expression levels of FGFR3, BCL2, MYC, CCND1 mRNA and protein in U266 cells decreased, and those of p53 mRNA and protein increased in a dose and time dependent manner. Conclusion UA exerts its anti-multiple myeloma effect by inhibiting the proliferation and inducing the apoptosis of U266 cells, thus providing the experimental evidence for the selection of new target therapy for multiple myeloma.