Role of the bone marrow microenvironment in multiple myeloma: Impact of niches on drug resistance mechanisms

Multiple myeloma (MM) is a blood cancer characterized by the uncontrolled growth of plasma cells in the bone marrow. These malignant plasma cells can proliferate locally and spread to other tissues and organs. The M-protein they produce can lead to various clinical symptoms, including anemia, hypercalcemia, bone pain, bone destruction, and kidney dysfunction. Despite significant advancements in treatment over the past two decades that have improved survival and outcomes for many patients, drug resistance remains a significant therapeutic challenge. This resistance is largely driven by the complex interactions between MM cells and the bone marrow microenvironment (BMME), making long-term disease control difficult. To improve treatment outcomes, it is essential to understand how the BMME supports MM cell growth and survival, as well as how these cells evade therapies. Investigating these processes will help identify key mechanisms behind drug resistance, offering a pathway to develop targeted therapies that can overcome this challenge. This review will explore the intricate relationship between MM cells and the BMME, focusing on how both cellular and non-cellular components of the microenvironment contribute to resistance mechanisms and prompt disease progression. These insights aim to inform future therapeutic strategies to enhance treatment options for MM patients.