A Novel Peptide HIF9-nano Complex Targeting Apoptosis 

Abstract In cancer therapy, cell proliferation can activate apoptotic machinery in the cell to suppress tumor growth. Though, the number of malignant cells does not effectively regulate the expression of vital genes that play a crucial role in the process of apoptosis in order to control. However, many malignant cells cannot regulate the genes that control apoptosis. Various intracellular and extracellular signals activate the process of apoptosis. The present investigation evaluated the anticancer effect of Peptide Chitosan Nanoparticles - M04 (PCN-M04) in the breast cancer cell line. PCN-M04 has a strong antiproliferative impact on breast cancer cells (MCF-7), indicating that it suppresses cancer cell growth in a dose-dependent manner. In order to assess the mode of cell death after treatment of PCN-M04 on breast cancer cells, various assays such as intracellular ROS formation, DNA fragmentation assay, Comet Assay and Mitochondrial membrane potential were performed. In addition, both gene and protein expression analyses were carried out by RT-PCR and Western blot analysis. The results suggested that PCN-M04 inhibits cell proliferation in MCF-7 cells in a dose-dependent manner. After 24 hrs treatment, PCN-M04 significantly elevates the ROS generation and effectively alters the mitochondrial membrane potential. The DNA fragment assay and comet assay results clearly depicted the DNA damage and nuclear fragmentation. Further, PCN-M04 significantly controls the expression of anti-apoptotic protein Bcl-2, increased Bax and subsequently leads to the elevation of apoptotic inducing protein p53 that releases from mitochondria and activates the other apoptotic inducing proteins such as Caspase-9 and 3. The overall results of the current study clearly indicated that PCN-M04 effectively induced the oxidative stress-mediated mitochondrial signaling mechanism by which it induces cell death. Hence, the novel peptide-based nanoformulation (PCN-M04) could be a potent therapeutic agent to inhibit or treat breast cancer.