Abstract:
Breast cancer has become an escalating disease that has highly significant ramifications for future global health. In Malaysia, breast cancer is the number one cancer killer and affects the health of Malaysian Women from all Walks of life. Novel approaches on diagnosis and treatment of breast cancer are urgently needed to improve the clinical outcome of these patients.
Recent studies have suggested that mesenchymal stem cells (MSCs) can migrate to and incorporate Within the tumour tissues This finding offers a novel Way to deliver therapeutic agents to the tumour sites. In the study, We propose to generate genetically engineered MSCs (GE-MSCs) that express and secrete two anti-tumour cytokines, IL-12 and IL-I8 The efficacy of these GE-MSCs Will then be tested in vitro on a panel of breast carcinoma cell lines (MCF-7, MDA-MB-231, and T-47D)
In the present study, bone marrow-derived MSCs were characterized by immunophenotyping analysis and differentiation studies The plastic-adherent cells can be referred as MSCs as set by the International Society for Cellular Therapy. MSCs were also found to selectively migrate towards all breast carcinoma cells tested in a dose- dependent manner (p<0.05) in vitro.
pBLAST42/hlL-12 and pFUSE/hIL-18 recombinant plasmid were successfully constructed and GE-MSCs Were generated by nucleofection with these plasmids and antibiotic selection. IL-12 and IL-18 secreted by GE-MSCs were able to induce IFN-7 production by peripheral blood mononuclear cells (PBMCs). A marked increase was observed When both cytokines were used, demonstrating their synergistic effects. Apart from that, these GE-MSCs retained the basic properties of MSCs such as differential plasticity and migration abilities.
The GE-MSCs appear to possess potent antiproliferative and cytotoxic effects against breast carcinoma cells in the T-cell mediated and NK-cell mediated cytotoxicity assays. Further experiments have shown that the cytotoxicity observed may be partially owing to the induction of apoptosis by T cells and the induction of apoptosis and necrosis by NK cells, and the utility of GE-MSC to initiate apoptosis or necrosis Was specifically aimed at breast carcinoma cells, but not at non-tumourigenic breast cells. MSCs also do not prevent the priming of T cell activation as GE-MSCs Were capable of activating unprimed T lymphocytes by up-regulating the activation marker CD69. Increased expression of the surface molecule in T lymphocytes may in part enhance the treatment efficacy.
