Liver cancer is one of the most common malignant tumors worldwide. Currently, the available treatment methods cannot fully control its recurrence and mortality rate. Establishing appropriate animal models for liver cancer is crucial for developing new treatment technologies and strategies. The patient-derived xenograft (PDX) model preserves the tumor's microenvironment and heterogeneity, which makes it advantageous for biological research, drug evaluation, personalized medicine, and other purposes. This article reviews the development, preparation techniques, application fields, and challenges of PDX models in liver cancer, providing insights for the research and exploration of PDX models in diagnostic and therapeutic strategies of liver cancer.
Liver Neoplasms/drug therapy* ; Animals ; Humans ; Xenograft Model Antitumor Assays/methods* ; Mice ; Disease Models, Animal

Objective:To establish a tumor tissue xenograft (PDX) model derived from liver cancer patients and explore the factors affecting tumorigenicity of liver cancer in the PDX model.Methods:The hepatocellular carcinoma tissues were inoculated subcutaneously in the axilla of NPG mice using the tissue block method to establish a PDX model. The demographic characteristics and related clinical examination data of 60 hepatocellular carcinoma patients were collected using the electronic medical record system and comprehensive medical information system of Beijing You'an Hospital, affiliated to Capital Medical University. The hepatocellular carcinoma samples of 24 cases were sequenced using the Oak Wing TM-808 gene detection reagent and high-throughput sequencing technology. SPSS 17.0 statistical software was used for statistical analysis, and the count data were analyzed using the χ2 test. Results:The tumorigenicity rate of PDX samples from 60 patients with liver cancer was 35% (21/60). The average tumorigenic duration in the PDX-P0 generation was 110.71±50.45 days. There were statistically significant differences ( P<0.05) corresponding to Edmondson grade ( χ2=5.910, P=0.015) and Ki67 expression ( χ2=4.615, P=0.032) among PDX with tumorigenicity and without tumorigenicity between the liver cancer samples. There was no statistically significant difference in gene mutation (TOP25) among PDX with tumorigenicity and without tumorigenicity between liver cancer samples. Conclusion:The factors affecting the tumorigenicity of liver cancer in PDX models are complex. The high pathological grade and strong Ki67 expression may be the key factors for the completion of liver cancer in PDX models.

Objective:To investigate the inhibitory effect of Huqizhengxiao decoction (HQZXD) on subcutaneous tumor in H22 hepatoma-bearing mice and its potential mechanism.Methods:Twenty-five healthy male BALB/c inbred mice aged 4 to 6 weeks and weighing (20±2) g were taken. One of them was used for the amplification of H22 hepatoma cells. The amplified H22 hepatoma cells were inoculated subcutaneously at the left posterior axillary line of the remaining mice for modeling. After subcutaneous tumor formation, the mice were randomly divided into four groups: model group, HQZXD group, sorafenib group and combined (HQZXD+ sorafenib) group, with 6 mice in each group. Tumor inhibition rates, and serum levels of aspartate transaminase (AST) and alanine transaminase (ALT) were observed. The expression of interleukin (IL)-6, signal transducer and activator of transcription 3 (STAT3), phosphorylated STAT3 (p-STAT3), and nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) in tumor tissues was detected using immunohistochemistry and Western blotting. Enzyme-linked immunosorbent assay was used to quantify the levels of IL-6, tumor necrosis factor-alpha (TNF-α), and IL-1β in tumor tissues. Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to assess the mRNA levels of IL-6, STAT3, and C-X-C motif chemokine ligand 1 (CXCL1) in tumor tissues.Results:The general condition of mice in all treatment groups improved compared to the model group. Notably, the tumor weight (0.50±0.22) g and tumor volume (0.37±0.18) cm 3 in the combined group were significantly lower than those in the model group [tumor weight: (1.63±0.26) g, tumor volume: (0.98±0.83) cm 3] with statistical significance (both P<0.05). The tumor inhibition rates for the sorafenib, HQZXD, and combination groups were 35.4%, 48.6%, and 69.7%, respectively. Compared to the model group, serum levels of AST and ALT were reduced in all treatment groups, with the combined group showing the most significant decrease [AST: (48.81±2.82) U/L vs. (188.12±6.51) U/L; ALT: (34.14±1.25) U/L vs. (116.62±4.72) U/L], and the differences were statistically significant (both P<0.05). The protein expression levels of IL-6, STAT3, p-STAT3, IL-1β, TNF-α, and NLRP3 in tumor tissues were reduced in all treatment groups compared to the model group, with the combined group showing the most marked reduction, and the differences were statistically significant (all P<0.05). Similarly, the mRNA levels of IL-6, STAT3, and CXCL1 in tumor tissues were lower in all treatment groups compared to the model group, with the combined group showing lower levels than the single treatment groups, and these differences were statistically significant (all P<0.05). Conclusion:HQZXD can inhibit the activation of IL-6/STAT3 pathway, reduce inflammation in tumors, and consequently play a certain inhibitory effect on tumor.

Objective:To establish a tumor tissue xenograft (PDX) model derived from liver cancer patients and explore the factors affecting tumorigenicity of liver cancer in the PDX model.Methods:The hepatocellular carcinoma tissues were inoculated subcutaneously in the axilla of NPG mice using the tissue block method to establish a PDX model. The demographic characteristics and related clinical examination data of 60 hepatocellular carcinoma patients were collected using the electronic medical record system and comprehensive medical information system of Beijing You'an Hospital, affiliated to Capital Medical University. The hepatocellular carcinoma samples of 24 cases were sequenced using the Oak Wing TM-808 gene detection reagent and high-throughput sequencing technology. SPSS 17.0 statistical software was used for statistical analysis, and the count data were analyzed using the χ2 test. Results:The tumorigenicity rate of PDX samples from 60 patients with liver cancer was 35% (21/60). The average tumorigenic duration in the PDX-P0 generation was 110.71±50.45 days. There were statistically significant differences ( P<0.05) corresponding to Edmondson grade ( χ2=5.910, P=0.015) and Ki67 expression ( χ2=4.615, P=0.032) among PDX with tumorigenicity and without tumorigenicity between the liver cancer samples. There was no statistically significant difference in gene mutation (TOP25) among PDX with tumorigenicity and without tumorigenicity between liver cancer samples. Conclusion:The factors affecting the tumorigenicity of liver cancer in PDX models are complex. The high pathological grade and strong Ki67 expression may be the key factors for the completion of liver cancer in PDX models.

Objective:To investigate the inhibitory effect of Huqizhengxiao decoction (HQZXD) on subcutaneous tumor in H22 hepatoma-bearing mice and its potential mechanism.Methods:Twenty-five healthy male BALB/c inbred mice aged 4 to 6 weeks and weighing (20±2) g were taken. One of them was used for the amplification of H22 hepatoma cells. The amplified H22 hepatoma cells were inoculated subcutaneously at the left posterior axillary line of the remaining mice for modeling. After subcutaneous tumor formation, the mice were randomly divided into four groups: model group, HQZXD group, sorafenib group and combined (HQZXD+ sorafenib) group, with 6 mice in each group. Tumor inhibition rates, and serum levels of aspartate transaminase (AST) and alanine transaminase (ALT) were observed. The expression of interleukin (IL)-6, signal transducer and activator of transcription 3 (STAT3), phosphorylated STAT3 (p-STAT3), and nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) in tumor tissues was detected using immunohistochemistry and Western blotting. Enzyme-linked immunosorbent assay was used to quantify the levels of IL-6, tumor necrosis factor-alpha (TNF-α), and IL-1β in tumor tissues. Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to assess the mRNA levels of IL-6, STAT3, and C-X-C motif chemokine ligand 1 (CXCL1) in tumor tissues.Results:The general condition of mice in all treatment groups improved compared to the model group. Notably, the tumor weight (0.50±0.22) g and tumor volume (0.37±0.18) cm 3 in the combined group were significantly lower than those in the model group [tumor weight: (1.63±0.26) g, tumor volume: (0.98±0.83) cm 3] with statistical significance (both P<0.05). The tumor inhibition rates for the sorafenib, HQZXD, and combination groups were 35.4%, 48.6%, and 69.7%, respectively. Compared to the model group, serum levels of AST and ALT were reduced in all treatment groups, with the combined group showing the most significant decrease [AST: (48.81±2.82) U/L vs. (188.12±6.51) U/L; ALT: (34.14±1.25) U/L vs. (116.62±4.72) U/L], and the differences were statistically significant (both P<0.05). The protein expression levels of IL-6, STAT3, p-STAT3, IL-1β, TNF-α, and NLRP3 in tumor tissues were reduced in all treatment groups compared to the model group, with the combined group showing the most marked reduction, and the differences were statistically significant (all P<0.05). Similarly, the mRNA levels of IL-6, STAT3, and CXCL1 in tumor tissues were lower in all treatment groups compared to the model group, with the combined group showing lower levels than the single treatment groups, and these differences were statistically significant (all P<0.05). Conclusion:HQZXD can inhibit the activation of IL-6/STAT3 pathway, reduce inflammation in tumors, and consequently play a certain inhibitory effect on tumor.

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 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.

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.