Bone marrow mesenchymal stem cells enrich breast cancer stem cell population via targeting metabolic pathways

The role of cancer cell metabolic reprogramming in the formation and maintenance of cancer stem cells (CSCs) has been well established. This reprogramming involves alterations in the metabolic pathways of cancer cells, leading to the acquisition of stem cell-like properties such as self-renewal and differentiation. This study aimed to investigate the potential effects of bone marrow mesenchymal stem cells (BM-MSCs) on the enrichment of breast CSCs. Exosomes (Exo) and conditioned media (CM) were isolated from BM-MSCs for use in this experimental study. The impact of BM-MSCs-Exo and BM-MSCs-CM on the expression of stemness genes NANOG and OCT-4, as well as CD24 and CD44 markers, was assessed in MCF-7 and MDA-MB-231 cell cultures to identify CSCs. Furthermore, the effects of BM-MSCs-Exo and BM-MSCs-CM on cancer cell metabolism were evaluated by examining changes in glycolysis, the pentose phosphate pathway (PPP), and amino acid profiles. Additionally, the influence of BM-MSCs-Exo and BM-MSCs-CM on tumor growth in vivo was also investigated. The analysis of stemness marker expression in cells treated with BM-MSCs-Exo and BM-MSCs-CM revealed an increase in stemness characteristics compared to the control group. Furthermore, the examination of changes in cell metabolism following these treatments showed alterations in glycolysis, PPP, and amino acid metabolism pathways. Additionally, it was demonstrated that BM-MSCs-Exo and BM-MSCs-CM can promote tumor growth in mice following transplantation of 4T1 cells. These findings suggest that BM-MSCs-Exo and BM-MSCs-CM can enrich the population of CSCs in MCF-7 and MDA-MB-231 cells by targeting metabolic pathways, however, further studies are required to elicit the exact mechanisms of these phenomena.