中文摘要：

目的：探讨大黄素抗人乳腺癌MCF-7细胞增殖及其相关机制。方法：采用MTT法检测大黄素对MCF-7细胞的增殖抑制作用；流式细胞术分析周期分布和凋亡情况；原子力显微镜（AFM）观察细胞膜表面超微结构的变化。结果：大黄素呈剂量依赖性地抑制MCF-7细胞的增殖；大黄素能使MCF-7细胞阻滞在G0／G。期；AnnexinV／PI双染法结果表明，大黄素对MCF-7细胞没有明显的促凋亡作用。AFM观察细胞膜超微结构，结果显示对照组细胞核区饱满，膜表面平坦光滑；大黄素作用48h可致细胞核区坍塌萎缩，细胞表面颗粒密集，膜表面的平均粗糙度（aa）和均方粗糙度（Rq）与对照组相比均有显著增加（P〈0．05）。结论：大黄素通过阻断MCF-7细胞的细胞周期进程及影响细胞膜超微结构而发挥抗肿瘤作用。

英文摘要：

AIM： To investigate the effects of emodin on the proliferation of human breast cancer MCF-7 cells and its mechanisms. METHODS ： MTT assay was used to observe the viability of MCF-7 cells. The cell cycle distribution and apoptosis of MCF-7 cells was analyzed by flow cytometry. The membrane surface morphology and three-dimensional ul- trastrueture of MCF-7 cells were observed under atomic force microscope （AFM）. RESULTS： MTr assay showed that emodin could inhibit MCF-7 cell proliferation in a dose-dependent manner. Flow cytometric analysis demonstrated that emo- dininduced cell cycle arrest at G0/G1 phase. Annexin V/PI double staining confirmed that emodin had no effect on cell apoptosis. AFM images revealed that the cell nuclear area was full and the surface of cell membrane was flat and smooth in control group. Compared with control group, the cell nuclear area collapsed and shrank in emodin group at 48 h. The cell membrane ultrastructure showed that the particles in emo-din group had an intensive distribution. The height of cell nuclear area was decreased, and the surface average roughness （Ra） and root mean square roughness （Rq） were elevated in emo- din group compared with control group. CONCLUSION： Emodin has cytotoxicity on MCF-7 cells via cell cycle arrest at Go/G1 phase and ultrastructural changes. [