Study Of EGCG Derivatives Of Structural Modification On Anti-hepatocarcinoma Angiogenesis

Objective:Hepatocellular carcinoma(HCC)is a serious threat to human survival,is also a high incidence of a regional tumor in our country.Studies have shown that(-)-epigallocatechin-3-gallate(EGCG)inhibit the growth of tumor and tumor blood vessels.But due to the particularity of EGCG structure,nature is not stable,easily oxidized,and poor fat-soluble,biological utilization rate is low,the body metabolism,drug interaction strength needs to be improved.To this end,we preliminary EGCG as the parent compound,through the optimization of structural modification,independent acetylation was synthesized and ethylation EGCG(AcEGCG and Y6).Through compared with EGCG,discuss the acetylation and ethylation derivate inhibit the growth of human liver blood vessels and its molecular mechanisms.For the better development of EGCG derivatives become new targets more HCC drug resistance to provide experimental basis and theoretical basis.Methods:Cultured human umbilical vein endothelial cells(HUVEC),detection of EGCG by the MTT method and its derivatives on human umbilical vein endothelial cells and the influence of drugs under anoxic/oxygen often applied to the cultivation of the hepatocellular carcinoma in supernatant affect endothelial cell proliferation;ELISA method for detection of EGCG and its of VEGF protein expression;Immunohistochemical mderivatives in anoxic/oxygen for hepatocellular carcinoma under the influence ethod to detect hepatocellular carcinoma under anoxia/oxygen often p-ERK1/2 protein localization;Western Blot detection under the anoxic/oxygen often develop,EGCG and its derivatives for hepatocellular carcinoma in the,MAPK/ERK signaling pathway(and join ERK1/2 inhibitor PD98059)phosphorylation protein p-ERK1/2 expression changes and PI3K/AKT signaling pathway(and join AKT inhibitors LY294002)p-AKT phosphorylated protein expression and changes of HIF-1 alpha and VEGF protein expression changes.Results:EGCG and its derivatives on human umbilical vein endothelial cells have a certain degree of inhibition,EGCG,AcEGCG and Y6 IC50 were 209.3 umol/L,97.9 umol/L,62.7 umol/L.EGCG and its derivatives role respectively in hepatocellular carcinoma SMMC-7721 cells and HepG2 cells,anoxic/oxygen conditions often develop 24/48 hour after collecting supernatant of the tumor to human umbilical vein endothelial cells with different degree of inhibition of proliferation,especially in Y6 strongest,AcEGCG times,EGCG weakest;ELISA method measured EGCG VEGF protein expression and its derivatives for hepatocellular carcinoma measuring tool has certain drug dose dependent,strength of the Y6>AcEGCG>EGCG,and often compared group,oxygen higher protein expression of hypoxia group(P<0.05);Immunohistochemical staining,according to the results of p-ERK1/2 proteins are mainly distributed in liver cancer SMMC-7721 cell nucleus,individual specimen has weak staining nucleus and cell membrane;EGCG and its derivatives can reduce hepatocellular carcinoma MAPK/ERK signaling pathway in the expression of ERK1/2 protein,a dose dependent,and the oxygen contents of phosphorylated proteins compared with often oxygen group increased significantly(p<0.05),after joining inhibitors(PD98059),p-ERK1/2 content decreased significantly,HIF-1 alpha and VEGF levels are significantly reduced;EGCG and its derivatives can reduce hepatocellular carcinoma p-AKT PI3K/AKT signal channel protein expression,in a dose dependent,and the hypoxia group phosphorylation protein compared with often oxygen group increased significantly(p<0.05),after joining inhibitors(LY294002),p-AKT content decreased significantly,HIF-1 alpha and VEGF levels are significantly reduced,to explain the MAPK/ERK and PI3K/AKT signaling pathways are involved in HIF-1 alpha and VEGF expression regulation.Conclusion:(1).The EGCG and its derivatives AcEGCG?Y6 can directly inhibit the production of vascular endothelial cells and AcEGCG and Y6 inhibitory effect than lead compounds EGCG,again with Y6 strongest.(2).Hepatocellular carcinoma under hypoxia conditions by HIF-1 alpha high expression,stimulate the VEGF levels increase,promote endothelial cell proliferation,EGCG and its derivatives AcEGCG?Y6 can indirectly inhibit endothelial cell proliferation.(3).EGCG derivative effect on HCC cells MAPK/ERK and PI3K/AKT signaling pathway were Inhibition of HIF-1 alpha and VEGF protein expression.