BACKGROUND: Compared to those original viruses systems, adeasy adenovirus, a recombinant adenoviral system widely used in recent years, based on viruses with a deletion of both El and E3, reported by T.C. He in 1998, is an improved one. It simplifies the generation and production of such viruses and expedite the process of generating and testing recombinant adenoviruses using homologous recombination in bacteria rather than in eukaryotic cells. Moreover, it can be conveniently followed with the aid of green fluorescent protein encoded by EGFP gene incorporated into the viral backbone.OBJECTIVE: To construct the recombinant adenovirus and to evaluate them by transfect them to mesenchymal stem cells (MSCs)and detect the expression of target gene hlGF-I at gene and protein levels.DESIGN: Repetitive measurement wail.SETTING: The Institute of Pediatric Research, Chongqing University of Medical Science.METHODS: The study was performed at the Institute of Pediatric Research, Chongqing University of Medical Science from November 2004 to March 2005. After the amplification of truncated hlGF-1 gene from pcDNA3.l-hlGF-I by polymerase chain reaction (PCR), the gene fragment was inserted into the shuttle plasmid pAdtrack-CMV for homologous recombination with backbone plasmid pAdeasy-I in bacteria BJ5183 to get adenovirus.Ad-hlGF-1. The high titer adenovirus supernatant was obtained by repeated transducing of HEK 293 cells by adenovirus harvested after confirmation of the adenovirus structure. As target cells,MSCs were infected with adenovirus earned target gene, hIGF-1, to determine the expression of hlGF-1 gene.MAIN OUTCOME MEASURES: ① The construction of recombinant adenovirus vector;② the expression of target gene hIGF-1 in HEK 293 cells and the proper multiplicity of infection (MOI); ③ hIGF-1 gene expression in MSCs.RESULTS: The adenovirus vector based on adeasy system was constructed successfully and the Ad-hlGF transducing was successfully or efficiently expressed in MSCs cells. The ideal expression of harvested recombinant adenovirus in MSCs was detected by fluorescence microscope, RT-PCR, immunocytochemistry, and Western Blot.CONCLUSION: Adenovirus vector is an effective vector tools for gene expression and wansfection of MSCs. MSCs transduced with Ad-hIGF-1 maybe another option to gene-modified seed cells for articular cartilage tissue engineering.

Objective To investigate the predictive value of the combined tumor burden score (TBS) and platelet-albumin-bilirubin (PALBI) score model for postoperative tumor recurrence in liver transplant recipients with hepatocellular carcinoma (HCC). Methods The general information of 158 recipients diagnosed with HCC and underwent liver transplantation at the 900th Hospital of the Joint Logistics Support Force of the Chinese People's Liberation Army from 2008 to 2021 was collected. Lasso regression analysis combined with multivariate Cox regression analysis were used to identify independent risk factors for postoperative tumor recurrence after liver transplantation with HCC. A nomogram prediction model was constructed based on variables selected by Lasso regression analysis, and the predictive performance of the model was verified by calibration curve and clinical decision curve. The optimal cut-off values for postoperative tumor recurrence in liver transplant recipients with HCC were determined by receiver operating characteristic (ROC) curve, and Kaplan-Meier analysis was used to compare survival differences among different groups. Results Among the 158 liver transplant recipients with HCC, 82 experienced tumor recurrence, with a recurrence rate of 51.9% and a median tumor-free survival time of 10 (4, 25) months. Results of Lasso regression analysis and multivariate Cox regression analysis showed that alpha-fetoprotein (AFP) ≥400 ng/mL, TBS and PALBI score were all independent risk factors for postoperative tumor recurrence in liver transplant recipients with HCC (all P<0.05). The combined high TBS-high PALBI score showed the highest predictive value (hazard ratio 6.909, 95% confidence interval 3.067-15.563, P<0.001). A nomogram prediction model was constructed based on six variables selected by Lasso regression analysis. Calibration curve showed good consistency between the model's predicted results and the ideal curve. Decision curve analysis indicated that the nomogram prediction model provided the highest clinical benefit for predicting 1-year tumor-free survival after liver transplantation with HCC. Time-dependent ROC curves at 1, 3 and 5 years after surgery showed that TBS-PALBI model had good predictive performance, with no significant difference in area under the curve (AUC) compared with TBS-PALBI-AFP model. The optimal cut-off values for predicting postoperative tumor recurrence were determined by ROC curve, with a PALBI score cut-off of −2.334 and a TBS cut-off of 5.305. Recipients were divided into a low TBS-low PALBI score group (n=47) and a low/high TBS-low/high PALBI score group (at least one score was high) (n=111). Kaplan-Meier survival analysis showed that the low TBS-low PALBI score group had a higher tumor-free survival rate than the low/high TBS-low/high PALBI score group, with a significant difference (P<0.05). Conclusions TBS-PALBI model provides a novel, simple and effective tool for assessing the prognosis of liver transplant recipients with HCC. The nomogram model constructed based on this has significant advantages in predictive performance and may serve as a reference for guiding individualized treatment plans and improving clinical outcomes.