MFN1 and osteosarcoma: Fusion proteins, Mfn-1, Mfn-2, and Opa1, were significantly suppressed by Tan IIA treatment, whereas a significant increase of the fission protein, Drp1, was increased (Fig. 7d).To validate the critical role of Drp1 in osteosarcoma 143B cells, RNA interference strategy was employed to investigate the consequence of Drp1 knockdown on the Western blot.