Mechanism Of Ursolic Acid Inhabiting The Proliferation Of Gliocytoma And Vascular Endothelialcell By ERK Extracelluar Signaltransduction Pathway

Objective: To investigate the effects of the expression of ERK1,C-Jun,C-Myc,Cyclin D1 of Human Umbilical Vein Endothelial Cells (HUVEC) in ursolic acid,and the effects of ursolic acid on the expression of ERK1,C-Jun,C-Myc,Cyclin D1 and CD34 in transplanlationumor of malignant glioblastoma cell line C6 in nude mice ,and to explore the mechanism of in effect of ursolic acid on glioma.Methods: 1. HUVEC was treated with ursolic acid and PD98059 or with ursolic acid at 0,31. 5,62.5,125,250,500ug/ml for 24h,or with ursolic acid at 125ug/ml for 0,12,24,48h for the course assay in vitro.RT-PCR was performed to measure the endogenous levels of ERK1,C-Jun,C-Myc,Cyclin D1 mRNA,Western blotting was use to detect the protein expression of ERK1,C-Jun,C-Myc,Cyclin D1. 2. C6 glioblastoma cells were injected into subcutaneously nude mice to establish the subcutaneous model of glioblastoma in nude mice,then the mouse models were assigned 3 groups: blank comtrol group,Ursolic acid group(50 mg·kg-1·d-1, intra-abdominal injection,20 days), PD98059 group (2 mg·kg-1·d-1, intra-abdominal injection,7 days). Living of nude mice,growth and histopathological changes of the tumors were observed. The expression of ERK1,C-Jun,C-Myc and Cyclin D1 and CD34 and the expression of ERK1 mRNA of the tumor tissues were detected by immunohistochemical technique(IHC) and in suit hybridization(ISH), respectively.Results: RT-PCR results showed that the mRNA level of ERK1,C-Jun,C-Myc,Cyclin D1 were decreased obviously after treated with ursolic acid and PD98059,and the degression is in a dose- and time-dependent manner after treated with ursolic acid(p<0.05).Western blotting results showed that the protein expression of ERK1,C-Jun,C-Myc,Cyclin D1 were all decreased obviously were decreased obviously after treated with ursolic acid and PD98059 ,and the descent is in a dose- and time-dependent manner after treated with ursolic acid(p<0.05).Immunohistochemical technique(IHC) results showed that the expression of the protein of ERK1,C-Jun,C-Myc,Cyclin D1 and CD34 of Ursolic acid group and PD98059 group were obviously lower than the control group(P<0.05) ,respectively.In suit hybridization(ISH) results showed the expression of ERK1 mRNA of Ursolic acid group and PD98059 group were also obviously lower than the control group(P<0.05).Conclusion: Ursolic acid could inhibited the expression of ERK1,C-Jun,C-Myc,Cyclin D1 mRNA and protein expression of HUVEC ,and those changes were dose- and time-dependent (p<0.05).Ursolic acid could also significantly inhibited the implanted glioma of C6 glioblastoma cells the protein expression of ERK1,C-Jun,C-Myc,Cyclin D1 and CD34 ,and the expression ERK1 mRNA.Our study demonstrated that Ursolic acid significantly inhibited the generation of Vascular endothelial cell of glioma and glioblastoma cells by down- regulating the expression of ERK1,C-Jun,C-Myc and Cyclin D1 of ERK signal transduction pathway.