Senescent bone marrow mesenchymal stem cells promote multiple myeloma cell proliferation through galectins-3

Fan Tingting; Xiang Miaomiao; Yuan Xiaoshuang; Yang Xu; Yang Bo; Tian Ting; Chen Xiaoxu; Tang Dongxin; Wang Feiqing; Liu Yang; Li Yanju

doi:10.12307/2026.395

Abstract：BACKGROUND:Studies showed that multiple myeloma microenvironment has the function of inducing mesenchymal stem cells to become senescent phenotype,while the effect of senescent bone marrow mesenchymal stem cells on multiple myeloma cells is rarely reported. OBJECTIVE:To investigate the effect of senescent bone marrow mesenchymal stem cells on the proliferation of multiple myeloma cells through paracrine galectin-3. METHODS:Bone marrow blood was collected from healthy donors,and bone marrow mesenchymal stem cells were extracted by Ficoll density gradient centrifugation and adherent purification.The third-generation bone marrow mesenchymal stem cells were taken and induced with 200 µmol/L hydrogen peroxide solution for 2 hours.After the treatment was completed,they were replaced with L-DMEM complete medium for 24 hours of culture to construct the senescent bone marrow mesenchymal stem cell model.β-Galactosylase staining and senescence gene P21 were used for identification.Meanwhile,the expression of galectin-3 in aging bone marrow mesenchymal stem cells was detected by RT-qPCR.The supernatant of senescent bone marrow mesenchymal stem cells was collected and the conditioned medium of senescent bone marrow mesenchymal stem cells was prepared by centrifugal concentration.After culturing the multiple myeloma cell line U266 for 24 hours with it,the proliferation of U266 cells was detected by CCK-8 assay.The apoptosis of U266 cells was detected by flow cytometry.The expression levels of BCL-2 protein and mRNA in U266 cells were detected by RT-qPCR and western blot assay.Bone marrow blood was collected from patients with multiple myeloma and healthy individuals.The level of galectin-3 was detected by ELISA. RESULTS AND CONCLUSION:(1)After hydrogen peroxide induction,the number of cells positive for β-galactosidase staining increased significantly,and P21 and galectin-3 mRNA expression levels were upregulated(P<0.01).(2)Compared with the control group,24 hours of culture of U266 cells with conditioned medium from senescent bone marrow mesenchymal stem cells increased the level of cell proliferation(P<0.05),decreased the apoptosis rate(P<0.05),and rose the expression levels of BCL-2 protein and mRNA(P<0.05).(3)Galectin-3 levels in the bone marrow of patients with multiple myeloma were significantly higher than those in healthy controls(P<0.05).These results suggest that senescent bone marrow mesenchymal stem cells may promote the proliferation of multiple myeloma cells by paracrine galectin-3,which in turn upregulates BCL-2 expression.