Objective To construct a recombinant eukaryotic expression vector of human tumor suppressor p53-binding protein 2(TP53BP2)and transfect human embryonic kidney Expi293F cells.High-purity recombinant human full-length TP53BP2 protein was obtained and its biological activity was identified.Methods The TP53BP2 gene sequence was queried on the UniProt website,and the Expi293F expression system was optimized.The TP53BP2 gene was connected to pcDNA3.1(+)-P2A-eGFP vector by homologous recombination,and identified by double enzyme digestion and sequencing.Transect pcDNA3.1(+)-P2A-eGFP-TP53BP2 plasmid into Expi293F cells of Polyethylenimine(PEI),observe the transfection efficiency with a fluorescence microscope,collected cells from the experiment group and control group.The expression level of TP53BP2 recombinant protein was detected by Western blot(WB).Protein was purified by His label purification kit and Superdex 20010/300 GL chromatographic column.Sodium dodecyl sulfate-polyacrylamide gel electrophoresis.The purified recombinant protein was identified by SDS-PAGE.Combining recombinant human full-length TP53BP2 protein with p65 protein was investigated for Co-immunoprecipitation(Co-IP)precipitation.Recombinant human full-length TP53BP2 protein was co-localized with p65 protein by Immunofluorescence(IF).The surface plasmon resonance(SPR)technique was used to detect the interaction between purified recombinant human full-length TP53BP2 protein and TP53BP2 antibody.Results The recombinant plasmid pcDNA3.1(+)-P2A-eGFP-TP53BP2 was successfully constructed by sequencing and double digestion.The fluorescence microscopy results showed that the transfection efficiency was about 60%.WB showed that the TP53BP2 protein was overexpressed in Expi293F cells,which proved that transfection was successful.SDS-PAGE results showed that the purity of the purified recombinant protein was above 90%,which proved that the purification was successful.Co-IP results showed that the TP53BP2 could interact with p65 protein.The results of IF showed that His tag protein,TP53BP2 protein,and p65 protein were co-located,indicating the interaction between the three proteins.SPR results showed that the purified TP53BP2 recombinant protein had good binding activity with the TP53BP2 antibody.These results all prove that the recombinant human full-length TP53BP2 protein has biological activity.Conclusion The eukaryotic expression vector of TP53BP2 gene was successfully constructed and the recombinant full-length human TP53BP2 protein with biological activity was successfully expressed in human embryonic kidney Expi293F cells.It lays a foundation for further study on the structure and function of TP53BP2.

Objective:To construct apoptosis-stimulating of p53 protein 2 (ASPP2) gene knockout mice using diethylnitrosamine (DEN)-induced liver cancer model to study the biological functions of ASPP2.Methods:The sgRNA oligonucleotides were constructed, and ASPP2 knockout mice were prepared with the CRISPR/Cas9 system. PCR and sequencing methods were used to identify the genotypes of F0 and F1 generations and their progeny. DEN was used to induce ASPP2+/- mice to establish liver cancer model.Results:PCR and sequencing results showed that ASPP2 gene was successfully knocked out in F0 generation mice. The genotype of F1 generation mice was accorded with ASPP2+/- and had obtained stable heredity. The success rate of DEN-induced liver cancer model (7/8 and 3 / 8) of ASPP2 + /-mice obtained by self-hybridization of F1 generation was significantly higher than that of wild-type mice.Conclusion:ASPP2 knockout mice were successfully constructed based on the CRISPR/Cas9 system. The success rate of DEN-induced liver cancer model of ASPP2 knockout mice was significantly higher than that of the wild-type mice.

Objective:To investigate the molecular mechanism of sorafenib against hepatocellular carcinoma.Methods:Sorafenib efficacy was screened and verified by the hepatocellular carcinoma patient-derived tumor xenograft (PDX) model. Veterinary B-mode ultrasonography and in vivo confocal laser scanning microscopy were used to observe PDX angiogenesis. Immunohistochemistry was used to observe the expression of proliferation and angiogenesis-related proteins in PDX tissue. Real-time quantitative PCR technology was used to observe the RUNX3 gene in PDX tissues. SPSS 17.0 statistical software was used for statistical analysis.Results:Four cases of PDX were used to screen the efficacy of sorafenib. PDX1 had a significant response to sorafenib, with an inhibition rate of 68.07%. Compared with the control group, sorafenib had significantly inhibited PDX1 relative tumor volume (5.76±2.14 vs. 11.71±2.87, P<0.05). Cell division index (39.50±7.72 vs. 67.10±9.14, P<0.05) and Ki67 expression (288.6±43.40 vs. 531.70±55.60, P<0.05) were significantly decreased. Veterinary B-mode ultrasonography showed evident blood flow signals in PDX1 tumors. In vivo confocal laser scanning microscopy results showed that sorafenib had significantly reduced the total vessel length (1573.00±236.21 vs. 2675.03±162.00, P<0.05) and area (11 145.33±1931.97 vs. 20 105.37±885.93, P<0.05)) of PDX1 tumors. Immunohistochemical results showed that sorafenib had significantly down-regulated the protein expressions of CD34 (27.55±3.76 vs. 45.47±5.57, P<0.05), VEGF (16.33±2.86 vs. 22.77±3.20, P<0.05) and MVD (38.75±6.01 vs. 55.50±8.61, P<0.05). Real-time PCR results showed that sorafenib had significantly up-regulated RUNX3 gene expression (2.14±0.71 vs. 1.00±0.36, P<0.05). However, there was a negative correlation between the expression of RUNX3 gene and the ratio of VEGF-positive cells in sorafenib group ( R2=0.509 7). Conclusion:Sorafenib may inhibit the PDX angiogenesis and the growth of hepatocellular carcinoma by regulating the RUNX3-VEGF pathway.