Trabectedin to induce mitochondrial membrane potential dissipation and reactive oxygen species generation in breast cancer cells.

e13580 Background: Trabectedin (Yondelis; ET-743) is a tetrahydroisoquinoline alkaloid that was originally derived from the marine tunicate Ecteinascidia turbinata and is currently prepared synthetically. It ıs currently used for the treatment of soft tissue sarcomas. It has been shown that Trabectedin provides the production of superoxides near the DNA strand, resulting in DNA backbone cleavage and cell apoptosis, however the apoptotic mechanisms of Trabectedin is still very limited. The objective of this study is to investigate the underlying mechanisms of apoptosis Trabectedin in two human breast cancer cell lines (MDA-MB-231 and MDA-MB-453) and one human immortalized non-transformed breast epithelial cell line (MCF-10A), to see if similar oxidation processes take place in breast cancer. Methods: Cytotoxicity was assessed by XTT cell viability assay. Apoptosis was shown by measuring DNA fragmentation, caspase 3/7 activation. Mitochondrial membrane potential (MMP) was evaluated by TMRE dye. Measurement of reactive oxygen species (ROS) was done by using Glutathione S-Transferase (GST) Assay Kit and CM-H2DCFDA dye. Results: Trabectedin induced the cytotoxicity in breast cancer cells in a time and dose dependent manner. Moreover, it increased DNA fragmentation and the MMP dissipation in tested breast cancer cells. The levels of ROS production in parallel with GST enzyme activity were sharply increased by Trabectedin treatment. Conclusions: This is the first study to investigate the role of Trabectedin activity and mechanisms of apoptosis in human breast cancer cells. These preliminary results might show us a way to use Trabectedin alone, or in combination for breast cancer treatment in near future.