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.