Analysis of biochemical markers of MCF-7 cell apoptosis induced by a recombinant analogue of lactaptin

Earlier, a pro-apoptotic peptide lactaptin was isolated from human milk and characterized and its recombinant analogue RL2 was generated. Both peptides were demonstrated to be capable of apoptotic cell death induction in human breast adenocarcinoma MCF-7 cells. In the work, biochemical markers of RL2-induced MCF-7 apoptosis are analyzed. Activation of initiator and effector caspases, as well as apoptotic changes in mitochondrial membrane potential and cytoplasm membrane composition in cells treated with RL2, were analyzed using flow cytometry and Western blot techniques. MCF-7 cell death induced by RL2 was found to be associated with phosphatidylserine exposure on the surface of the plasma membrane. Also, RL2 was demonstrated to induce dissipation of the mitochondrial membrane potential and activation of initiator caspases 8 and 9 and an effector caspase 7.