The effect of mesenchymal stem cell-conditioned medium on proliferation and apoptosis of breast cancer cell line.

Bone marrow-derived mesenchymal stem cells (MSCs) have the potential ability to differentiate into bone, muscle, fat, and cartilage lineage cells. Furthermore, MSCs are known to migrate into tumor-associated stroma of cancer. This tumor microenvironment consists of a dynamic network of growth factors, immune cells, fibroblasts, extracellular matrix, and MSCs. MSCs as nonhematopoietic stem cells affect tumor, epithelial cells by alteration proliferative capacity, morphology, and aggregation pattern of tumor cells.This research aimed to further elucidate the MSCs effects in the progress of proliferation, cell cycle, and apoptosis in breast cancer by gene expression analysis in human breast cancer cell lines exposed to MSCs conditioned media (CM). Expression pattern of two genes, including survivin (Birc5) as anti-apoptotic gene and serine threonine kinase 15 as proliferative gene, were studied.Anti-apoptotic and proliferative genes were up-regulated in co-cultured breast tumor cells with MSCs-CM that correlate with tumor progression and poor prognosis.Our results and other findings indicate the interaction of breast tumor cells with MSCs through paracrine factors. Also, the applications of MSCs as therapeutic tools are facing controversial concerns.