In vitro effects of 2-methoxyestradiol-bis-sulphamate on reactive oxygen species and possible apoptosis induction in a breast adenocarcinoma cell line

BACKGROUND: In the search for anticancer agents, a promising 17-β-estradiol metabolite, 2-methoxyestradiol (2ME2) was found that exerts antiproliferative in vitro and in vivo activity. Since 2ME2 has limited biological accessibility and rapid metabolic degradation, the purpose of this study was to investigate the in vitro influence exerted by an analogue of 2ME2 namely 2-methoxyestradiol-bis-sulphamate (2MEBM) in a breast adenocarcinoma cell line (MCF-7). METHODS: This was conducted by investigating 2MEBM's in vitro influence on cell cycle progression, mitochondrial membrane potential and possible production of reactive oxygen species (ROS) generation. In vitro effects of 2MEBM on cell cycle progression was demonstrated by means of flow cytometry using propidium iodide. Hydrogen peroxide and superoxide production was investigated using 2,7-dichlorofluorescein diacetate and hydroethidine, respectively. The probable reduction in the mitochondrial membrane potential was demonstrated using a MitoCapture™ kit. RESULTS: Cell cycle progression revealed the presence of a sub-G(1 )apoptotic peak. Reduction of mitochondrial membrane potential after exposure to 2MEBM was demonstrated and an increase in ROS production was also observed. CONCLUSION: This study verified that 2MEBM exposure resulted in apoptosis induction, increased ROS production and reduced mitochondrial membrane potential in a tumorigenic breast epithelial cell line. Data obtained from this project contributes to the unravelling of the in vitro signal transduction of 2MEBM in tumorigenic cell lines.