中文摘要：

目的：研究鬼臼毒素衍生物YB-1EPN对人口腔鳞状上皮癌细胞系（KB）增殖的抑制作用。方法：以KB细胞为研究对象,采用MTT法检测细胞毒作用;荧光染色法观察细胞形态学变化;RT-PCR法检测半胱天冬氨酸蛋白酶（Caspase）-3mRNA的表达;激光共聚焦显微镜观察药物对细胞微管结构的影响。结果：4μmol·L-1YB-1EPN能够直接抑制和杀伤KB细胞;荧光显微镜观察到4μmol·L-1YB-1EPN干预24h后KB细胞出现凋亡小体;RT-PCR法检测到在1、2、4μmol·L-1YB-1EPN干预下KB细胞促凋亡基因Caspase-3表达上调;激光共聚焦显微镜观察到在2、4μmol·L-1YB-1EPN干预24h后KB细胞微管结构被破坏。结论：YB-1EPN能够直接抑制和杀伤KB细胞株,作用机制可能与促凋亡基因的表达上调和抑制微管蛋白聚合有关。

英文摘要：

OBJECTIVE： To study the inhibitory effect of podophyllotoxin derivative （YB-1EPN） against the growth of human oral squamous epithelium cancer cell（KB）. METHODS： MTT assay was used to detect cytotoxic effect of KB cell; Fluorescent staining method was used to observe the changes of cell morphology; expression of caspase-3 mRNA were measured by RT-PCR assay, and the effect of drugs on microtubules was observed by laser scanning microscope. RESULTS： YB-1EPN（4 μmol·L-1）was demonstrated to exert antiproliferative activity in dose and time dependent manner. Typical apoptotic morphological changes were observed by fluorescence microscope; RT-PCR assay showed that YB-1EPN（1、2、4 μmol·L-1）up-regulated mRNA expression of Caspase-3 dramatically, and the structure of microtubulin was destroyed by laser confocal microscope. CONCLUSION： YB-1EPN show obvious anticancer activity by inducing apoptosis in the dose-dependent manner, which are accompanied by up-regulating Caspase-3 and inhibiting the microtubule polymerization.