Identification and Characterization of Multiple Myeloma Stem Cell-Like Cells

SIMPLE SUMMARY: Although the existence of multiple myeloma (MM) cancer stem cells is controversial, a large number of studies have shown that there is a kind of cells in multiple myeloma that has stronger proliferation, migration, tumorigenesis, and drug resistance than general tumor cells, and so we call them the multiple myeloma stem cell-like population. Therefore, the definition, screening, and targeted inhibition of these cells are very important. In this paper, we list the markers used to screen the MM stem cell-like population and the research of related inhibitors in MM treatment and introduce the pathways related to stemness in MM and the main target molecules in these pathways. ABSTRACT: Multiple myeloma (MM) is a B-cell tumor of the blood system with high incidence and poor prognosis. With a further understanding of the pathogenesis of MM and the bone marrow microenvironment, a variety of adjuvant cell therapies and new drugs have been developed. However, the drug resistance and high relapse rate of MM have not been fundamentally resolved. Studies have shown that, in patients with MM, there is a type of poorly differentiated progenitor cell (MM stem cell-like cells, MMSCs). Although there is no recognized standard for identification and classification, it is confirmed that they are closely related to the drug resistance and relapse of MM. This article therefore systematically summarizes the latest developments in MMSCs with possible markers of MMSCs, introduces the mechanism of how MMSCs work in MM resistance and recurrence, and discusses the active pathways that related to stemness of MM.