Multiple myeloma (MM) is a hematological malignancy that is characterized by clonal proliferation of transformed plasma cells within the bone marrow (BM) and severe bone disease. Although MM cells are initially sensitive to many therapies, patients eventually relapse with refractory disease. Because MM cells show a dependency on the BM microenvironment for survival and proliferation, and BM adipocytes (BMAs) demonstrate a unique, endocrine signaling capacity and lipid composition, it is likely that there is cross-talk between MM cells and BMAs that leads to tumor support. Unlike the influences of osteoblasts and osteoclasts, the effect of BMAs on MM cells is poorly understood and few studies have investigated the relationship between bone marrow adipose tissue (BMAT) and cancer. We predict there to be a strong link between MAT and MM, as obesity is a risk factor for MM and also correlates with increased MAT in humans. Moreover, MAT has been shown to support other tumors and correlates with bone diseases such as osteoporosis, anorexia, and aging. Thus, we explored here the novel hypothesis that BMAs induce drug resistance in MM cells through direct cell-cell contact signaling and/or secreted signaling molecules
