【摘要】 目的:对非苯醌格尔德霉素进行酶法糖基化修饰,并探讨其糖基化产物对乳腺癌细胞增殖、凋亡的影响。方法:利用体外酶法糖基化反应制备新型非苯醌格尔德霉素糖基化产物,并经质谱和核磁共振解析鉴定其结构。采用孔雀绿-钼酸铵显色反应、MTT法、PI单染/流式细胞术检测化合物的体外抗肿瘤活性。免疫印迹法检测化合物对Akt、Bcl-2及热休克蛋白90(Hsp90)表达的影响。结果:新型非苯醌格尔德霉素糖基化产物鉴别为17-demethoxy-reblastatin-18-O-β-D-glucopyranoside(1)。化合物1具有显著抑制Hsp90 ATPase活性,其IC50值为8. 98μmol/L。化合物1对人乳腺癌MCF-7细胞表现出一定的抑制增殖、诱导凋亡的作用,且呈现浓度依赖性。免疫印迹法结果显示,随着化合物1浓度的增加,诱导Akt和Bcl-2蛋白的降解越明显,而对Hsp90蛋白的表达没有影响。结论:新型Hsp90抑制剂化合物1具有抑制MCF-7细胞增殖、诱导凋亡能力,其机制可能是通过抑制Hsp90 ATPase活性以及诱导降解Hsp90顾客蛋白Akt和Bcl-2有关。更多还原

【Abstract】 Objective: To explore the effects of the enzymatic glycosylation product modified by enzymatically non-benzoquinone geldanamycin( GA) on the proliferation and apoptosis of breast cancer cells. Methods: A new non-benzoquinone GA glucoside was prepared using enzymatic glycosylation in vitro. The product was characterized by ESI-MS and nuclear magnetic resonance( NMR)analysis. The anti-cancer activities of the compound were evaluated using malachite green-molybda colour reaction,MTT assay and flow cytometry with PI staining in vitro. The effects of the compound on expression levels of Akt,Bcl-2 and heat shock protein 90( Hsp90)were detected using Western blot. Results: The structure of novel non-benzoquinone GA glucoside was characterized as 17-demethoxyreblastatin-18-O-β-D-glucopyranoside( 1). Compound 1 could significantly inhibit the activity of Hsp90 ATPase,the IC50 value of which was 8. 98 μmol/L. Compound 1 could inhibit the proliferation,and induce apoptosis in MCF-7 cells of human breast cancer in a concentration-dependent manner. The results of Western blot showed that,with the increasing of compound 1 concentration,the induced degradation of Akt and bcl-2 protein was more obvious,while the expression of Hsp90 protein was not affected. Conclusions: The new Hsp90 inhibitor,compound 1,can inhibit the proliferation,and induce apoptosis of MCF-7 cells,the mechanism of which may be by inhibiting the activity of Hsp90 ATPase,and inducing the degradation of Hsp90 client protein Akt and Bcl-2.更多还原