中文摘要：

目的探讨细胞周期蛋白激酶抑制剂（flavopiridol）在体内外抑制骨肉瘤耐阿霉素细胞株MG63/ADR增殖的作用及其机制。方法四甲基偶氮唑蓝法（MTT法）测定细胞增殖抑制率。流式细胞计数法测量flavopiridol给药后MG63/ADR细胞周期的变化及凋亡率。免疫印迹法（Western-blot）检测细胞中pro-caspase-9、pro-caspase-3、caspase-8、Bcl-2、Bcl-xL、p53、Bax及活化型多聚ADP核糖多聚酶（PARP-85）蛋白的表达。采用MG63/ADR建立荷瘤裸鼠模型,FP腹腔内给药,测量肿瘤体积及裸鼠体质量变化,计算肿瘤抑制率。结果 Flavopiridol可抑制骨肉瘤耐阿霉素细胞株MG63/ADR的细胞增殖,其效果呈时间及浓度依赖性。Flavopiridol给药后,耐药细胞株MG63/ADR的细胞凋亡率明显高于对照组（P〈0.05）。Flavopiridol给药后,耐药细胞株中的pro-caspase-9、pro-caspase-3、Bcl-2以及Bcl-xL的表达下降,活化型caspase-8、PARP-85的表达增加。Flavopiridol可有效抑制荷瘤小鼠体内耐药骨细胞的生长。结论细胞周期蛋白激酶抑制可在体外及体内有效抑制骨肉瘤耐药细胞株的增殖,其机制可能与死亡受体介导的caspase信号传导途径及非p53介导的线粒体凋亡信号传导途径相关。

英文摘要：

Objective To investigate the growth-inhibition and apoptosis effects of flavopiridol on human osteosareoma MG63/ADR cell and the related mechanism both in vitro and in vivo. Methods The proliferation of MG63 and MG63/ADR cells was determined by using MTT method. Cell cycle progression and apoptosis ratio were determined by flow cytometry. The expressions of pro-easpase-9, pro-caspase-3, cas- pase-8, Bcl-2, Bel-xL, p53, Bax and cleaved-PARP were detected by Western blot. The subcutaneous tumors of MG63/ADR cells were also established in nude mice to study the antitumor effects of flavopiridol. Results After exposure to flavopiridol,the growth of MG63/ADR cells were inhibited in a time- and dose-dependent manner. Apoptosis rate of MG63/ADR was higher than control group （ P 〈0.05 ）. The ex- pressions of pro-caspase-9, pro-casepase-3, Bcl-2 and Bcl-xL were down-regulated, and the expression of active-form PARP and active-form caspase-8 were up-regulated. The expressions of p53 and Bax were not affected. The in vivo inhibitory effect on ADR clones of osteosarcoma in the treatment group was observed compared with the control group. Conclusion Flavopiridol can inhibit the growth of drug-resistant os- teosarcoma cells both in vitro and vivo. The apoptosis of MG63/ADR cells induced by flavopiridol might via easpase cascade pathway and p53-independent mitochondrial apeptosis pathway.