Fluid Shear Stress Regulated The Proliferation,Invasion And Apoptosis Of MG-63 Cells Through The ERK5 Signaling Pathway

OBJECTIVE:To explore the role of fluid shear stress(FSS)in osteosarcoma and to find potential molecular targets.METHODS:First of all,MG-63 human osteosarcoma cells were resuscitated,cultured and frozen.Cell groups were loaded with the FSS of 12 dyn/cm~2 for 0 min,15min,30 min,45 min,60 min and 90 min,respectively.Then,total proteins of each group were extracted and the expression levels of PCNA,MMP 2,caspase 3,ERK5 and P-ERK5 in each group were sequentially measured by Western blots to determine the optimal time for FSS on MG-63 cells.Finally,in order to further study the mechanisms of FSS on MG-63 cells,the cells were divided into four groups:Control group,FSS group,XMD8-92 group and FSS+XMD8-92 group.The total proteins were extracted after the corresponding interventions were taken.The expression levels of PCNA,Cyclin D1,MMP 2,MMP 9,caspase 3,caspase 9,BAX,BAD,ERK5 and P-ERK5 in each group were detected by Western blots in turn.Each experimental data was repeated three times.The gray value of WB bands were measured by Image J.SPSS 22.0 was used as statistical software.RESULTS:The expression levels of PCNA,MMP 2 and P-ERK5 increased with the prolongation of FSS loading time and reached a peak at 60 minutes.The expression level of caspase 3 decreased with the prolongation of FSS loading time and reached a trough at 60 minutes.These indicated that the physiological strength FSS could promote the proliferation and invasion of osteosarcoma and inhibit apoptosis.Subsequent mechanistic experiments have found that FSS could promote the expression of PCNA,Cyclin D1,MMP 2,MMP 9 and P-ERK5 through the ERK5 signaling pathway.These indicated that FSS could promote the proliferation and invasion of osteosarcoma cells through the ERK5 signaling pathway.FSS could also inhibit the expression levels of caspase 3,caspase 9,BAX and BAD through the ERK5 signaling pathway.These indicated that FSS could inhibit the apoptosis of MG-63 cells through the ERK5signaling pathway.CONCLUSIONS:FSS could promote the proliferation and invasion of osteosarcoma cells and inhibit its apoptosis.FSS could exert its tumor-promoting effect through the ERK5 signaling pathway.As an inhibitor of ERK5,XMD8-92 could antagonize the promotion effect of FSS on tumor.