Adipokine Role in Normal and Neoplastic Bone Marrow Niche

Bone marrow (BM) niche is an appropriate site for the growth of mesenchymal stem cells and their differentiation into adipocytes. Adipocytes are metabolically active cells affecting the function of their neighboring cells through the secretion of adipokines, growth factors, and inflammatory mediators. Although the pathological roles of adipokines have not been elucidated, the changes in their levels have been observed in various malignancies. Adipokines also affect tumor growth in the BM niche. Decreased levels of adipokines and increased levels of leptin have been reported in a number of cancers. Adipocytes can be introduced as a diagnostic marker of metastasis in some cancers. Identification of the relationship between different adipokines secreted from adipocytes and the signaling pathways activated by these adipokines, as well as the detection of molecules involved in the development of various types of malignancies, can contribute to the recognition of drug resistance factors and appropriate treatment of malignancies. In this review paper, we examine the effects of various BM-derived adipokines on the growth and metastasis of tumor cells in the neoplastic BM niche.