Novel Midkine Inhibitor Induces Cell Cycle Arrest and Apoptosis in Multiple Myeloma

Background/Aim: Multiple myeloma (MM), the second most common hematological malignancy, is characterized by the accumulation of malignant plasma cells within the bone marrow. Despite various drug classes for MM treatment, it remains incurable, necessitating novel and efficacious agents. This study aims to explore the anti-cancer activity of a midkine inhibitor, iMDK (C₂₁H₁₃FN₂O₂S), in myeloma cell lines. Materials and Methods: This study assessed the antiproliferative activity using the MTT assay. Cell cycle and apoptosis were evaluated using flow cytometry. To further investigate the inhibitory mechanism, western blotting was used to detect cell cycle-related proteins, pro-apoptotic proteins, and anti-apoptotic proteins. Results: iMDK inhibits MM cell proliferation in a dose- and time-dependent manner, inducing cell cycle arrest and apoptosis. The reduction in Cdc20 expression by iMDK treatment leads to G₂/M phase cell cycle arrest. Furthermore, iMDK down-regulates anti-apoptotic proteins (Bcl-2, Bcl-xL, Mcl-1, and c-FLIP), thereby activating both intrinsic and extrinsic apoptosis pathways. Conclusion: iMDK could be a potential candidate for MM treatment.