Effects Of DTX3L On The Cell Proliferation,Adhesion,and Drug Resistance Of Multiple Myeloma Cells

ObjectiveTo explore the mechanism of DTX3 L in multiple myeloma(MM)cell adhesion and the role of DTX3 L in proteasome inhibitor(PI)resistance in MM cells.In order to improve the therapeutic effect and the prognosis of multiple myeloma,provide a new theoretical basis.Methods1.Using serum-free medium to culture multiple myeloma cells for 72 h,and then replaced with serum-containing medium myeloma cells for 48 h.Western Blot was used to detect the expression of DTX3 L,proliferation-associated protein PCNA,CDK2 and cyclinE during cell proliferation.At the same time,changes in the cell cycle were detected by flow cytometry.2.After interfering with the expression of DTX3 L in myeloma cells,the expression of PCNA,CDK2 and cyclinE were detected by Western Blot.The cell growth was detected by Cell Counting Kit-8(CCK-8),and the cell cycle was detected by flow cytometry.3.The myeloma cells RPMI8226,NCI-H929 and bone marrow stromal cells HS-5 or fibronectin(FN)co-cultured adhesion model.Western Blot was used to detect the expression of DTX3 L in4.myeloma cells suspension and adhesion;after interfering with the expression of DTX3 L in myeloma cells,the effect of DTX3 L expression on myeloma cell adhesion rate was detected by calcein assay.5.Interfering with DTX3 L expression in adherent myeloma cells.After treatment with bortezomib(bort),the expression of caspase3 and PARP were detected and the apoptosis of cells was detected.6.After interfering with the expression of DTX3 L in myeloma cells,Western Blot detects AKT,p-AKT,FAK,ERK and p-ERK expression.Results1.The expression of DTX3 L,PCNA,CDK2 and cyclinE increased continuously during the process of cell proliferation;G1phase decreased and S phase increased gradually in the cell cycle.2.After the interference of DTX3 L expression in myeloma cells,the expression of PCNA,CDK2 and cyclinE1 were decreased.At the same time,flow cytometry showed increased the G1 phase in the cell cycle.And CCK8 test showed that,after interfering with the expression of DTX3 L,the cells grew slowly.3.Myeloma cell adhesion culture,DTX3 L expression was increased.Calcein experiments showed that the adhesion of myeloma cells was decreased after interfering with the expression of DTX3 L.4.Bortezomib stimulated the adhesion of myeloma cells after interfering with the expression of DTX3 L.The expression of apoptosis-related proteins caspase3 and PARP were increased.Flow cytometry showed increased rates of apoptosis in myeloma cells.5.After the adhesion of Myeloma cell,FAK and AKT signaling pathway increased expression.After stimulation with bortezomib,it was found that the expression of FAK and AKT6.signaling pathway were decreased after interfering with DTX3 L expression.Conclusions1.The high expression of DTX3 L is closely related to the proliferation of multiple myeloma cells.2.Interfering with DTX3 L expression can inhibit the proliferation of multiple myeloma cells.3.High expression of DTX3 L can promote adhesion of multiple myeloma cells.4.Interference with DTX3 L expression can reduce cell adhesion-mediated drug resistance.5.The expression of DTX3 L in the course of CAM-DR in multiple myeloma cells is up-regulated by the FAK signaling pathway and may play a role by up-regulating the AKT signaling pathway.