Effects Of FasL Combined With SiRNA Silencing Of DcR3 On Apoptosis And Invasive Ability Of Human Hepatocellular Carcinoma

Background: Hepatocellular carcinoma is the sixth most prevalent cancer and the third most frequent cause of cancer-related death.There was about 466,100 people were diagnosed with liver cancer,and the death toll was about 422,000 in 2015.As the result of delayed diagnosis,many patients were already in the advanced stage when they first visited a doctor,so the prognosis is very poor,5-year survival rate less than 5%.So,it is urgert to study the pathogenesis of liver cancer and to find a new diagnostic and therapeutic targets for liver canncer for the prevention and treatment of liver cancer.The current focus of cancer treatment is the use of molecular biology technology to inhibit the expression of tumor-related genes in vivo to achieve the purpose of tumor gene therapy,and the related genes which can cause apoptosis of tumor cells is the focus of attention.Abnormal apoptosis pathway is the key to many human diseases,including tumorigenesis.Fas/Fas L system is an important apoptotic pathway playing an important role in maintaining immune homeostasis and tumorigenesis Fas L has two receptors,Fas and Dc R3(decoy receptor 3/TNFRSF6B).Dc R3 competitively binds to Fas L over Fas,inhibiting Fas L-induced apoptosis.It was found that Dc R3 expression level was directly related to Fas L-mediated apoptosis,and Dc R3 decreased Fas L-mediated cell apoptosis.But in HCC,there was no researches has been reported.Objective: In our previous study,we transfected human hepatoma Hep G2 cells with lentivirus-based short hairpin RNA vector targeting Dc R3 stably,in this study,our aims is to observe the effect of Fas L combined with silencing Dc R3 in hepatocellular carcinoma,in vitro and in vivo.The cell cycle,apoptosis,growth and clonal proliferation of Hep G2 cells were detected in our study,and the effect of Fas L on the expression of MMP9,VEGF-C and VEGF-D were also observed.Our pouposre is to provide experimental and theoretical basis for the gene therapy of hepatocellular carcinoma,and to provide experience for the prevention and treatment of other malignant tumors.Results:1.With Dc R3 knockdown,Fas L led to the increase of apoptosis,and changed the cell cycle.We found that cells of G0 / G1 phase were increased and cells of G2 / M phase were decreased.2.With Dc R3 knockdown,the activity of hepatocarcinoma cells was decreased with the treatment of Fas L.3.With Dc R3 knockdown,the ability of invasion and metastasis of hepatocarcinoma cells decreased further when Fas L was added.4.With Dc R3 knockdown,The m RNA and protein expression of MMP9,VEGF-C and VEGF-D in hepatocellular carcinoma cells were significantly decreased when Fas L was added.5.Fas L slowed down the growth of subcutaneous tumor in mice significantly,and decreased the expression of tumor-associated metastatic invasion factor.Conclusions:1.Fas L combined with Dc R3 silencing could increase apoptosis of hepatocellular carcinoma cells.2.Fas L combined with Dc R3 silencing can slow down the growth rate of hepatocellular carcinoma cells and decrease the ability of migration and invasion.3.The expression of MMP-9,VEGF-C and VEGF-D in hepatocarcinoma cells was decreased by the treatment of Fas L combined with Dc R3 silencing.4.Fas L combined with Dc R3 silencing can be a new research direction for the treatment of hepatocellular carcinoma.