Oncolytic Myxoma Virus Increases Autophagy in Multiple Myeloma

Alpay Yeşilaltay, Dilek Muz, Berna Erdal

Multiple myeloma (MM), which affects plasma cells, is the second most common hematological malignancy. Despite the development of new drugs and treatment protocols, patient survival has not reached the desired level. In this study, we investigated the effects of Myxoma virus (MYXV), an oncolytic virus, on autophagy in myeloma cells. We analyzed protein expression of ATG-5, p62, Beclin-1, LC3B, and the apoptosis marker Bcl-2 as autophagy markers in human U-266 and mouse MOPC 315 myeloma cell lines treated with different doses of MYXV. In addition, autophagic images in myeloma cells were investigated using transmission electron microscopy (TEM). In the first 24 hours, which is the early stage of autophagy, ATG-5 and Beclin-1 expression were increased in the U-266 and MOPC-315 cell lines in the groups that received 15 multiplicity of infection (moi) MYXV. At 48 hours, a significant increase was detected in the expression of LC3B, which is a late indicator. Autophagosomes were observed in myeloma cells on TEM. MYXV shows an antimyeloma effect by increasing autophagy in myeloma cells.