Effects Of Silencing Livin Gene By RNA Interference Carried By Lentiviral Vector On Tumor Proliferation In Nude Mice

BackgroundLung cancer is one of the most common malignancies worldwide ,Recent studies have suggested that Livin is highly expressed in lung cancer. It may be involved in tumorigenesis and development of lung cancer.In this study,we used RNA interference technology to silence Livin expression,then observed the effects of the proliferation of adenocarcinoma of lung cell SPC-A1, and then we established the tumor-bearing nude mice model of SPC-A-1, explored the possible mechanism in vivo.Objective:To inhibit the livin gene expression in nude mice by livin shRNA carried by lentiviral vector and to observe its effect in tumor apoptosis and proliferation in transplantation tumor of lung adenocarcinoma.Methods:SPC-A-1 was injected into nude mice to form subcutaneous lung adenocarcinoma model. All the nude mice were randomly divided into three groups according to tumor size the eighth day after inoculation:the blank group;the negative group;the experimental group. Different interventions were given for different groups in four consecutive days.①Experimental group:lentivirus-delivered livin shRNA were injected into tumo(r2×106TU,5ui)②Negative group:non-transfected lentivirus vectors were injected into tumor(2×106TU,5ul)③Blank group:NS were injected into tumor(5ul). The tumor growth was observed at the same time. The volume and weight of these tumors was measured in different time points. The curve of tumor growth was then described by SPSS18.0 software, and the inhibition rate was calculated. The expression of Livin and Ki67 were detected by western-blot and immunochemistry. The correlation of the expression of Livin and Ki67 was analysed at the same time. The study showed a slower tumor growth and a lighter tumor weight in experimental group than the blank and negative control groups (P<0.01). Immunohistochemistry showed that Livin protein expression was mainly located in the cytoplasm, while Ki67 protein expression was mainly located in the nucleolus. We found that the expression level of Livin and Ki67 proteins were significantly lower than the two control groups(P<0.01,P<0.01),and there was a positive correlation between the two proteins (r =0.54, P<0.01).Conclusions:The lentivirus-delivered livinshRNA can effectively inhibite the expression of livin gene and suppress the proliferation of transplantation tumor. livin may be a potent target of gene therapy in lung cancer. Results:...