cyclin-d1 and fangchinoline

Fangchinoline (Fan) inhibits cell proliferation and induces apoptosis in several cancer cell lines. The effects of Fan on cell growth and proliferation in breast cancer cells remain to be elucidated. Here, we show that Fan inhibited cell proliferation in the MDA-MB-231 breast cancer cell line through suppression of the AKT/Gsk- 3beta/cyclin D1 signaling pathway. Furthermore, Fan induced apoptosis by increasing the expression of Bax (relative to Bcl-2), active caspase 3 and cytochrome-c. Fan significantly inhibited cell proliferation of MDA- MB-231 cells in a concentration and time dependent manner as determined by MTT assay. Flow cytometry analysis demonstrated that Fan treatment of MDA-MB-231 cells resulted in cell cycle arrest at the G1 phase, which correlated with apparent downregulation of both mRNA and protein levels of both PCNA and cyclin D1. Further analysis demonstrated that Fan decreased the phosphorylation of AKT and GSK-3beta. In addition, Fan up-regulated active caspase3, cytochrome-c protein levels and the ratio of Bax/Bcl-2, accompanied by apoptosis. Taken together, these results suggest that Fan is a potential natural product for the treatment of breast cancer.

Topics: Apoptosis; Benzylisoquinolines; Blotting, Western; Breast Neoplasms; Cell Cycle; Cell Proliferation; Cyclin D1; Female; Flow Cytometry; Gene Expression Regulation, Neoplastic; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Humans; Phosphorylation; Proto-Oncogene Proteins c-akt; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tumor Cells, Cultured

Fangchinoline, an alkaloid derived from the dry roots of Stephaniae tetrandrine S. Moore (Menispermaceae), has been shown to possess cytotoxic, anti-inflammatory, and antioxidant properties. In this study, we used Fangchinoline to inhibit breast cancer cell proliferation and to investigate its underlying molecular mechanisms. Human breast cancer cell lines, MCF-7 and MDA-MB-231, were both used in this study. We found that Fangchinoline significantly decreased cell proliferation in a dose-dependent manner and induced G1-phase arrest in both cell lines. In addition, upon analysis of expression of cell cycle-related proteins, we found that Fangchinoline reduced expression of cyclin D1, cyclin D3, and cyclin E, and increased expression of the cyclin-dependent kinase (CDK) inhibitors, p21/WAF1, and p27/KIP1. Moreover, Fangchinoline also inhibited the kinase activities of CDK2, CDK4, and CDK6. These results suggest that Fangchinoline can inhibit human breast cancer cell proliferation and thus may have potential applications in cancer therapy.

Topics: Antineoplastic Agents, Phytogenic; Benzylisoquinolines; Breast Neoplasms; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Cyclin D3; Cyclin E; Cyclin-Dependent Kinase 2; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Cyclin-Dependent Kinase Inhibitor p21; Cyclin-Dependent Kinase Inhibitor p27; Dose-Response Relationship, Drug; Drugs, Chinese Herbal; Female; G1 Phase; Humans; Oncogene Proteins