Effect Of HER2 On Proliferation,migration And Invasion Of Osteosarcoma

Purpose: 1.To study the effect of HER2 on the proliferation,migration and invasion of osteosarcoma.2.To study whether HER2 regulates the expression of PCNA and MMP2 via PI3K/AKT pathway,so as to promote the proliferation,migration and invasion of osteosarcoma.Methods: 1.Western Blot was used to screen the highest and lowest expression of HER2 from MG63,Sa OS2,HOS and U2 OS osteosarcoma cells.2.HER2 interference lentivirus was transfected into the cell line with the highest expression of HER2,and HER2 overexpression lentivirus was transfected into the cell line with the lowest expression of HER2.3.Western blot was used to detect the expression of HER2 protein after transfection of HER2 interference lentivirus and HER2 over-expression lentivirus,and to verify whether HER2 was successfully knocked down or over-expressed.4.CCK8 assay was used to detect cell proliferation.5.Scratch test was used to observe the change of cell migration ability.6.Transwell method was used to observe the changes of cell invasiveness.7.The Western blot,was to detect the expression of p AKT473,p AKT308,AKT,PCNA and MMP2 in osteosarcoma HOS cells transfected with HER2 and those over-expressed with HER2 after adding PI3K/AKT pathway inhibitor LY294002.8.Drawing the growth curve of nude mice tumors to observe the effect of HER2 expression on the growth of nude mice transplanted tumors9.Immunofluorescence observation of PCNA and MMP2 protein expression in nude mice transplanted tumorsResults: HER2 protein was expressed in osteosarcoma cells of all groups.The expression of HER2 was the highest in human osteosarcoma MG63 cells and the lowest in osteosarcoma HOS cells.The expression of HER2 was significantly decreased after transfection of HER2 sh RNA lentivirus,and the expression of HER2 was significantly increased after transfection of HER2 overexpression lentivirus(P < 0.05).After inhibiting the expression of HER2,the proliferation,migration and invasiveness of osteosarcoma cells were inhibited.The proliferation,migration and invasiveness of osteosarcoma cells were promoted after overexpression of HER2.The expression of p AKT,PCNA and MMP2 increased after over-expression of HER2,but the increase of above-mentioned proteins was blocked by adding PI3K/AKT pathway inhibitor LY294002,and the effect of overexpression of HER2 on osteosarcoma cells was blocked.Inhibition of PI3K/AKT pathway in vivo can block the effect of HER2 on the growth and metastasis of osteosarcoma,and restore the expression of PCNA and MMP2.Conclusion: HER2 plays a tumorigenic role in osteosarcoma by promoting the proliferation,migration and invasion of osteosarcoma cells.