Methods: Organogold compounds IV and V induced death in Bak-/-Bax-/- double-knockout (DKO) and parental mouse embryonic fibroblasts (MEF). Bax and Bak are integral components of MAC. The cytotoxicity of the two compounds on both cell lines was assessed using alamar blue viability assays. The compounds’ mechanism in causing cell death in the parental cells was investigated by examining several markers for apoptosis and necrosis using fluorescence microscopy, including release of mitochondrial proteins, mitochondrial depolarization and changes in cell shape and nuclear morphology.
Results: Compound IV was more cytotoxic than compound V in either DKO or parental MEFs. However, the effect of compound IV was substantially attenuated in DKO cells, which suggested involvement of MAC. Furthermore, the treatments caused mitochondrial depolarization, which not only reinforced the involvement of mitochondrial-dependent pathways, but also suggested a role for mPTP. More experiments are underway to further examine the exact mechanisms by which MAC and mPTP are induced, especially in cancer cells.
Conclusions: MAC and mPTP are potential targets for chemotherapy since their involvement in the mitochondrial death pathways has been shown. This project is significant because it identifies new targets to increase the efficacy of current cancer treatments. Furthermore, it examines the mechanisms and evaluates the potential of organogold compounds as anti-tumor drugs.