Unleashing the Impact of Exosomes Derived from Human Placental Mesenchymal Stem Cells (hPMSCs) on U-266 Myeloma Cell Line.

Multiple myeloma (MM) is a malignancy of plasma cells, terminally differentiated B cells, with complications like hypercalcemia, renal failure, anemia, and bone disease, which are also known as CRAB criteria. MM develops from monoclonal gammopathy of unknown significance (MGUS), a pre-malignant plasma cell dyscrasia. Over some time, MGUS has the potential to progress into smoldering multiple myeloma (SMM), which can evolve into MM. MM rarely progresses into plasma cell leukemia (PCL), a condition in which malignant plasma cells no longer stay in the bone marrow niche and circulate in the peripheral blood. In MM, various soluble factors play important roles, and interleukin-6 has different vital roles.  Interleukin-6, an inflammatory cytokine, has significant roles in the growth, survival, angiogenesis, metastasis, and apoptosis resistance in MM. Interleukin-6 is produced and secreted by both autocrine from myeloma cells and paracrine from bone marrow stromal cells. To tackle MM, various therapeutic approaches were applied over many years, and according to the results, most patients with MM can respond well to first-line treatment. However, the majority of patients may relapse as conventional treatment may not be curative. So, there is an urgent need for novel cell-based and cell-free therapeutic strategies, such as mesenchymal stem cell-based therapies and their products to offer new therapeutic strategies for MM.