Study On The Inhibition Of EGCG On Ovarian Cancer Xenografts In Nude Mouse

Objective: To investigate the anticancer effect of epigallocatechin-3-gallate(EGCG)on ovarian cancer in vivo and in vitro,and explore its effect on PTEN/AKT/mTOR pathway.Aims to lay a foundation for identifing effective targets for molecular targeted therapy of ovarian cancer,and provide scientific basis for exploring drugs in the clinical treatment of ovarian cancer.Methods: 1.The changes of cell proliferation viabilities of SKOV3 cells after EGCG treatment were analyzed by MTT and clone formation experiments.Flow cytometry were used to detect apoptosis of SKOV3 cells after EGCG treatment.Quantitative PCR(Q-PCR)and Western blot were used to detect the expression of apoptosis pathway-associated factors Bax,Bcl-2 and caspase-3,and the PTEN/AKT/mTOR pathway-associated factors PTEN,PDK1,p-AKT and p-mTOR expressions in SKOV3 cells.2.VO-Ohpic(PTEN-specific inhibitor)and EGCG acted on SKOV3 cells respectively or cooperatively,the reversal effects of VO-Ohpic on the anti-cancer effect of EGCG in SKOV3 cells were evaluated by assays of cell proliferation,cell apoptosis and the detection of PTEN,PDK1,p-AKT,and p-mTOR expression.3.BALB/c nude mice were used to replicate SKOV3 transplanted tumor model,and they were randomly divided into negative control group,paclitaxel positive group(5 mg/kg),EGCG low,medium and high dose groups(10,30,50 mg/kg).All mice were killed after 21 days,and tumors were obtained to calculate tumor inhibition ratio.HE staining was used to observe the morphological changes of liver.Q-PCR and Western blot were used to detect the expression of PTEN,PDK1,p-AKT and p-mTOR in xenografts.Results:(1)EGCG significantly inhibited the proliferation and colony formation of SKOV3 cells.(2)EGCG promoted the apoptosis of SKOV3 cells,which was related to the up-regulation of Bax and caspase-3,and the down-regulation of Bcl-2.(3)VO-Ohpic reversed the proliferation inhibition,apoptosis induction and the expression of PTEN,PDK1,p-AKT and p-mTOR induced by EGCG.(4)EGCG showed a significant inhibitory effect on tumor growth.The inhibitory effect of high-dose EGCG group(growth ihnibit rate is 71.08%)on tumor growth is better than that of paclitaxel(growth ihnibit rate is 48.19%),and EGCG showed no significant effect to the liver of nude mice.(5)EGCG promoted PTEN expression and reduced the expression of PDK1,p-AKT,and p-mTOR in ovarian cancer cells and xenograft tumor tissues,thus,inhibited the activation of PTEN/AKT/mTOR pathway.Conclusions: EGCG showed obvious proliferation inhibition and apoptosis induction in SKOV3 cells in vitro,and significantly inhibited the growth of ovarian cancer xenografts in vivo.The mechanism related to the inhibition of PTEN/AKT/mTOR pathway.