目的:探讨白桦脂酸(BA)联合硼替佐米诱导多发性骨髓瘤(MM) U266细胞凋亡及其机制.方法:用不同浓度的BA(20、40、60及80 mg/L)、硼替佐米(10、80及320 nmol/L)、40 mg/L BA分别联合10、80及320 nmol/L硼替佐米(联合1～3组)处理U266细胞,MTT法检测上述各组U266细胞增殖抑制率;Real-time PCR和蛋白免疫印迹法(Westem blot)分别检测40 mg/L BA、80 nmol/L硼替佐米及40 mg/L BA联合80 nmol/L硼替佐米(联合4组)的U266细胞Survivin、Cyto-C、BCL-2及Bax的mRNA和蛋白表达水平.结果:联合1～3组对U266细胞增殖抑制率显著高于BA组和硼替佐米组(P＜0.05);与硼替佐米组和BA组相比,联合4组U266细胞的cyto-C,Bax mRNA和蛋白表达水平显著升高(P＜0.05),而Survivin、Bcl-2 mRNA和蛋白表达水平显著降低(P＜0.05).结论:BA联合硼替佐米可以促进MM肿瘤细胞凋亡,机制可能与下调Survivin、Bcl-2表达,上调Cy-to-c、Bax表达有关.

Objective:To investigate the betulinic acid combined with Thalidomide induce apoptosis of U266 cells and its mechanism. Methods:U266 cells were treated with betulinic acid(20,40,60 and 80 mg/L,betulinic acid group ),Thalidomide( 10 mg/L,50 mg/L,100 mg/L,Thalidomide group)and betulinic acid(40 mg/L)combined with Thalidomide( betulinic acid 40 mg/L,10,50 and 100 mg/L of Thalidomide,combined group)coupled with control group. Proliferation inhibition rate and apoptosis rate of U266 cells from different concentrations were detected with MTT and flow cy-tometry;Real-time PCR was used to detect the expression levels of Survivin,Cyto-C,Bcl-2,Bax gene. Western blotting was used to detect the expression of Survivin,Cyto-C,Bcl-2,Bax protein. Re-sults:With the increase of betulinic acid concentration,inhibition rate of U266 cells was also in-creased,differences were statistically significant( P <0. 05),the most appropriate concentration was 40 mg/L ;comparing with Thalidomide,inhibition rate and apoptosis rate of U266 cells were obviously increased,differences were statistically significant(P<0. 05);comparing with Thalidomide group or betulinic acid group,Survivin and expression of Bcl-2 mRNA of U2666 cells obviously decreased,Cy-to-C and expression of Bax mRNA obviously increased,differences were statistically significant(P<0. 05 ). Conclusion:The betulinic acid combined with thalidomide induce apoptosis of multiple myeloma U266 cells and its mechanism may be correlated with the proapoptotic molecule of survivin,Bcl-2,Cy-to-c and Bax.