The Role of Rarely Studied Chemokines in Tumor Progression in Multiple Myeloma (MM)

Multiple myeloma (MM) is a plasma cell neoplasm. Studies of chemokines in MM pathogenesis have primarily focused on CCR1 ligands such as CCL3 (MIP-1α), CXCL12 and its receptor CXCR4, as well as CXCR2 and CXCR3 ligands. However, the roles of the remaining 30 chemokines have been investigated much less frequently. This review compiles current knowledge on the significance of lesser-known chemokines in MM tumor processes, including CXCL13, CCR2 ligands (CCL2 [MCP-1], CCL7 [MCP-3]), CCL4, CCL5 (RANTES), CCL17, CCL20, CCL27, CCL28, and CX₃CL1 (fractalkine). It describes their impact on bone destruction, bone marrow angiogenesis, chemoresistance, and the recruitment of cells into the MM niche, such as macrophages, myeloid-derived suppressor cells, and cytotoxic lymphocytes, along with their effects on mesenchymal stromal cells. A bioinformatic analysis highlights the significance of these chemokines in MM, and the possibility of targeting them in MM therapy is also considered.