Pseudolaric acid B induces apoptosis, senescence, and mitotic arrest in human breast cancer MCF-7

• Published in: Acta pharmacologica Sinica Vol. 28; no. 12; pp. 1975 - 1983
• Main Authors: YU, Jing‐hua, CUI, Qiao, JIANG, Yuan‐yuan, YANG, Wei, TASHIRO, Shin‐ichi, ONODERA, Satoshi, IKEJIMA, Takashi
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.12.2007; Nature Publishing Group
• Subjects: apoptosis; Apoptosis - drug effects; Breast Neoplasms - pathology; Cell Division - drug effects; Cell Line, Tumor; Cellular Senescence - drug effects; Diterpenes - pharmacology; human breast cancer MCF‐7; Humans; Mitosis - drug effects; mitotic arrest; pseudolaric acid B; senescence; 有丝分裂; 细胞凋亡; 肿瘤细胞
• ISSN: 1671-4083; 1745-7254
• DOI: 10.1111/j.1745-7254.2007.00706.x

Aim： The aim of the present study was to investigate the inhibitory effect of pseudolaric acid B （PAB） on human breast cancer MCF-7 cells. Methods： 3-（4,5- dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide analysis, morphological changes, acridine orange staining, and agarose gel electrophoresis were applied to detect apoptosis. The percentage of apoptotic and necrotic cells was calcu- lated by the lactate dehydrogenase activity-based cytotoxicity assay; senescence associated （SA）-~-galactosidase activity was detected to evaluate senescence; flow cytometric analysis of propidium iodide staining was carried out to investi- gate the distribution of cell cycle, and the protein expression was examined by Western blot analysis. Results： During apoptosis, the half maximal inhibitory concentration IC5o was 3.4 and 1.35 μmol/L at 36 and 48 h after PAB treatment, respectively. The MCF-7 cells exposed to PAB showed typical characteristics of apoptosis, including the morphological changes and DNA fragmentation. The MCF-7 cells treated with 4 lamol/L PAB for 36 h underwent apoptosis, but not necrosis. The apoptosis induced by PAB was independent of the death receptor pathway. The senescent cells became larger and flatter, and the SA-β-galactosi- dase staining was positive. PAB induced obvious mitotic arrest and it preceded apoptosis and senescence. The expressions of p21 and p53 was upregulated with PAB treatment, and cyclin B 1 was upregulated and transported from the cyto- plasm to nuclei, and sustained stable levels. Conclusion： PAB induced mitotic arrest in the MCF-7 cells and inhibited proliferation through apoptosis and senescence. The apoptosis was independent of the death receptor pathway.