The Effect Of VEGF And PDGF In The Cell Proliferation And Invasion Of Choroidal Melanoma

Purpose: To explore the effect of vascular endothelial growth factor(VEGF)and Platelet-derived growth factor(PDGF)in the cell proliferation and invasion of Choroidal Melanoma(CM).Further identify their mechanism to find novel targets for CM therapy.Methods: This research investigated the molecular mechanism of VEGF and PDGF promoting cell proliferation and invasion of CM.Firstly,we evaluated the expression of VEGF and PDGF in 30 surgically resected human CM specimens by immunohistochemical determination.Secondly,we constructed the choroidal melanoma cell model OCM-1 in vitro by COCl2.Thirdly,we detected expressions of VEGF,PDGF,Akt,MT1-MMP,MMP2,and MMP9 of OCM-1 in hypoxia by Western blot and RT-PCR,to research mechanisms of VEGF and PDGF in tumor growth and metastasis.Furthermore with knocking out the gene of VEGF and PDGF separately and jointly by RNA interference technology,we verify the effect of VEGF and PDGF in the tumor growth and metastasis,and verify its mechanism.Results: The expressions of VEGF and PDGF were evaluated in 30 archival paraffin-embedded CM specimens by IHC assay.We found that all the 30 CM cases were positive for VEGF and PDGF and the high expressions of VEGF and PDGF along the blood vessels.In hypoxia,the expression of VEGF,PDGF,Akt,p-Akt,MT1-MMP,MMP-2 and MMP-9 was significantly enhance in OCM-1 compared with control group and low concentration of COCl2(P≤0.05).And it was concentration-dependent and time-dependent increasing in OCM-1.After knocking out the gene of VEGF or/and PDGF,the XTT indicated that the proliferation rate of the gene-deleted cell line was significantly lower than the control group;and the migration experiments showed that the group of gene-deleted cell line reduce the migration rate by 23%-42% than the control group,and the migration rate of the combined knockout group was less than 10%(P≤0.05).Transwell results revealed that the invasive ability was decrease compared with the normal group,but the apoptosis was remarkably increased in the gene-deleted cell line(P≤0.05).Further mechanism studies revealed that the expression of VEGF,PDGF,p-Akt,Akt,MT1-MMP,MMP-2 and MMP-9 were decreased after gene knockout;and the expression of p-Akt,Akt,MT1-MMP,MMP-2 and MMP-9 were also increased in hypoxia(P≤0.05).These indicated that VEGF and PDGF can promote tumor growth and invasion by Akt/MMP signal transduction pathway.Conclusion:1.VEGF and PDGF protein were expressed in a high percentage of CM;2.Hypoxia promotes the expression VEGF and PDGF in OCM-1 cells;3.VEGF and PDGF play a role in CM by activating Akt/MMP signal transduction pathway;4.VEGF and PDGF gene deletion inhibited the cell proliferation and invasion,it may be a new therapeutic target in the clinical treatment of CM.