Abstract:

bstract:Objective
To explore the influence  of  the expression level of cancerous inhibitor of protein phosphatase 2A(CIP2A)  in the hepatoma  HepB3 cell   in the apoptosis induced by Apoptin,and  to provide basis for studying the mechanism of  Apoptin in  the apoptin-specific induction of tumor cells.Methods CIP2A specific siRNA was synthesized and the  eukaryotic expression plasmid pcDNA3-HA-Apoptin was constructed.CIP2A siRNA and pcDNA3-HA-Apoptin were co-transfected into HepB3 cells  as experiment group,the HepB3 cells  co-transfected with pcDNA3-HA-Apoptin and CIP2A scrambled siRNA were regarded as positive control group,the HepB3 cells co-transfected with pcDNA3 and CIP2A siRNA were regarded as negative control group,and the HepB3 cells co-transfected with pcDNA3 and CIP2A scrambled siRNA were regarded as blank control group.Western blotting method was used to detect the expression levels of CIP2A and HA-Apoptin in HepB3 cells;the apoptotic rates of HepB3 cells  in different  groups  were detected by flow cytometry;immunofluorescence assay was utilized to determine the distribution  of Apoptin in nucleus or cytoplasm in HepB3 cells.Results The  Western blotting results showed that compared with negative control group,the expression level of CIP2A in the HepB3 cells in  experiment group was decreased（P<0.001）.The Western blotting and flow cytometry assay results showed  that the apoptotic rate  of HepB3 cells in experiment group was significantly reduced compared with positive control  group（P<0.05）.The immunofluorescence assay results indicated that   the HA-Apoptin distribution in cytoplasm of the  HepB3 cells in experiment group was increased compared with positive control group.Conclusion The  downregulating of the expression level of CIP2A in HepB3 cells decreases the induction effect of Apoption on apoptosis.

Key words: liver neoplasms, cancerous inhibitor of protein phosphatase 2A, Apoptin, apoptosis