2-methoxyestradiol induces apoptosis and cell cycle arrest in human chondrosarcoma cells

2-Methoxyestradiol (2ME) is an endogenous metabolite with estrogen receptor-independent anti-tumor activity. The current study seeks to determine the mechanism of antitumor activity of 2ME on human chondrosarcoma. 2ME caused a time- and dose-dependent cytotoxity in chondrosarcoma cells, while primary chondrocytes were minimally affected. Cells accumulated in G0/G1 phase in response to 2ME and DAPI stain indicated an induction of apoptosis. Bax, Cytochrome C, and Caspase-3 protein expression were increased, while p53 expression was decreased. A higher Bax/Bcl-2 ratio followed 2ME treatment. 2ME has a potentially promising role as a systemic therapy of chondrosarcoma when the mechanism of action is better delineated. (C) 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.