The most difficult field in gene therapy is that vector system should offer both a means of successful transfection and a maximum of safety for the patient. Viral vectors and plasmid vectors are traditional vectors; they may cause unwanted immunological side effects resulting from the expression of nontherapeutic genes. Our aim is to develop a new general gene therapy vector which is suggested to be called as Micro-Linear Vector. The gene expression cassette is capped by our designed cap, including promoter, enhancer, objective gene, and RNA-stabilizing sequence, so it can defend the exnuclease in the eukaryotic cell, at the same time, DNA not encoding the objective gene is reduced to a minimum. The GFP gene is separated from the pEGFP-N3 plasmid, and acts as a reporter gene to construct the Micro-Linear Vector, then both the new vector and the plasmid are transfected to cells, the results are tested by fluorescence microscope and flow cytometry. The results show that the Micro-Linear Vector has a high effective of transfection and safety in 293, 3T3, CNE2 and B95-8 cell lines, at the same time it is less toxicity than the plasmid. We can get the rudiments of conclusion that Micro-Linear Vector has high effection of the transfection and more safety than tradition plasmid in eukaryotic cell.
3T3 Cells ; Animals ; CpG Islands ; Genetic Therapy ; methods ; Genetic Vectors ; genetics ; Green Fluorescent Proteins ; genetics ; Humans ; Kidney ; cytology ; Mice ; Promoter Regions, Genetic ; genetics ; Transfection ; methods

Objective:To compare and analyze the clinical curative effect and safety of chemoembolization with drug-loaded microspheres of different particle sizes (D-TACE) for the treatment of hepatocellular carcinoma.Methods:Clinical data of 281 cases with hepatocellular carcinoma treated with drug-loaded microspheres-transarterial chemoembolization (TACE) were retrospectively analyzed. According to the different particle sizes of drug-loaded microspheres, they were divided into 100~300 μm (small particle size) and 300~500 μm (large particle size) group. Tumor response rate and complication conditions at 1, 3, and 6 months after chemoembolization were compared. The overall survival time of the two groups were analyzed. Quantitative data conformed to normal distribution and homogeneity of variance were compared using t-test, while other with Wilcoxon signed rank-sum test. Qualitative data were compared using χ2 test. Kaplan-Meier method was used for survival analysis, and the differences in survival were analyzed using Log-rank test. P＜0.05 was considered as statistically significant. Survival curves and histograms were drawn using GraphPad Prism9.1 software. Results:The complete remission rates at 1, 3 and 6 months after surgery in the small and large particle size groups were 31.25%, 30.15%, and 42.45% and 18.25%, 15.79% and 24.74%, respectively, and the differences were statistically significant between groups (P 1 month=0.012, P 3 month=0.009, P 6 month=0.008, P＜0.05). The objective remission rates at 1, 3 and 6 months after surgery in the small and large particle size groups were 88.19%, 76.99%, and 70.75% and 81.02%, 72.81% and 53.60%, respectively. Six months after surgery, the small particle size group (objective response rate = 70.75%) was significantly higher than the large particle size group (objective response rate=53.6%, P=0.012). The disease control rates of the small particle size group were 95.14%, 83.33%, and 74.53%, while large particle size group were 91.24%, 81.58%, and 64.95%, respectively, with no statistically significant difference between the two groups. However, the incidence of postoperative biliary tumors (6.20%) was significantly higher in the small-size than large-size group (0.70%), and the difference was statistically significant ( P＜0.05, P=0.03). There were no statistically significant differences between other adverse events such as post-embolization syndrome, liver abscess, and myelosuppression. The median survival time of the small and large particle size groups was 31.8 months and 20.5 months, respectively, but the difference was not statistically significant ( P=0.182). Conclusions:In the treatment of hepatocellular carcinoma with D-TACE, the short-term curative effect of the small particle size group was better than large particle size group, but the incidence of biliary tumors was high, and D-TACE of different particle sizes had no significant effect on long-term survival.