Extracellular vesicle-mediated delivery of microRNA-491 inhibits lung metastasis of osteosarcoma
Objective To investigate the inhibitory effect of extracellular vesicle(EV)-mediated microRNA(miR)-491 delivery on pulmonary metastasis of osteosarcoma.Methods MiR-491 was used to target the degradation of αB-crystallin(CRYAB)mRNA and protein in tibial origin osteosarcoma cells at the cellular level,and the following groups were set up:miR-NC group,miR-491 group,vector+miR-NC group,vector+miR-491 group,CRYAB+miR-NC group,CRYAB+miR-491 group.Subcutaneous adi-pose tissue of male patients undergoing fracture surgery in our hospital was collected and adipose-derived mesenchymal interstitium cells(AD-MSCs)were isolated.Extracellular vesicles Mir-491-EV and NC-EV were collected after miR-491 was overexpressed in AD-MSCs or negative control(NC).Subsequently,the mouse osteosarcoma lung metastasis model was established and divided into two groups:NC-EV group and miR-491-EV group,and the number of lung metastasis nodules and lung weight were detected.The differ-ence between different groups was detected by t test and ANOVA.Results CRYAB mRNA and protein levels in miR-491 group were lower than those in miR-NC group(1.00±0.03 vs.0.19±0.02,t=38.912,P<0.01).The invasion and migration ability of vector+miR-491 group was lower than that of vector+miR-NC group(1.00±0.08 vs.0.31±0.03,t=31.284,P<0.01;1.00±0.08 vs.0.28± 0.03,t=32.641,P<0.01).The invasion and migration ability of CRYAB+miR-NC group was higher than that of vector+miR-NC group(1.00±0.08 vs.3.22±0.18,t=43.650,P<0.01;1.00±0.08 vs.1.88±0.23,t=14.000,P<0.01).The number of metastatic pulmonary nodules in miR-491-EV group(6.03±1.21 vs.1.02±0.23,F=154.412,P<0.05)and lung weight(0.68±0.09 vs.0.47± 0.04,F=43.254,P<0.05)were lower than those in NC-EV group.Conclusion MiR-491 can act as a tumor suppressor by down-regulating CRYAB expression in osteosarcoma.miR-491 enriched EV derived from AD-MSCs can be used as a potential therapy for metastatic osteosarcoma.