Objective To construct a new recombinant immunotoxin expression vector by using human VEGF165 and a truncated pseudomonas exotoxin A ramification (PE38) gene, and explore the expression of the VEGF165-PE38 fusion protein in HEK293 cells. Methods VEGF165 was cloned by polymerase chain reaction (PCR). PE38 gene was gained from an vector plasmid pRB391 by restriction endonuclease digestion, and then inserted to the eukaryotic expression vector pIRES2-EGFP. After the eukaryotic recombinant vector pIRES2-VEGF165-PE38-EGFP was identified by restriction endonuclease digestion and sequence analysis, the vector was transfected into HEK293 cells by liposome protocol. RT-PCR and ELISA method was used to confirm the expression of the fusion gene in the HEK293 cells. Results Restriction endonuclease digestion and sequence analysis revealed the VEGF165-PE38 fusion gene was cloned into the eukaryotic expression plasmid vector pIRES2-EGFP successfully. The pIRES2-VEGF165-PE38-EGFP fusion gene could express in the HEK293 cells. Conclusion The result provide the basis for search of the targeted cytotoxic activity to tumor vascular endothelial cells and may have some potential value in clinical application.

Objective Glioma stem cells (GSCs) are the root causes ofglioblastoma recurrence.Glioma expresses low level of micro RNA 124 (miR-124), which plays an important role in the development of glioma.In this study, we explore the mechanisms miR-124 by overexpressing miR-124 in GSCs.Methods Human GSCs were transfected with lentivirus mediated miR-124 overexpression vector (pGC-miR-124-GSCs group), and GSCs in normal culture were used as control group.Cell proliferation was accessed by MTT assay, and stem cell phenotype was analyzed by flow cytometry.Quantitative real time PCR was employed to detect the miR-124 expression and its target genes (A kt and RelA) expressions;and ELISA was carried out to detect the secretions of downstream inflammatory cytokines interleukin (IL)-1 and IL-8.Results The lentiviral miR-124 expression vector was constructed successfully and transfected into human GSCs (pGC-miR-124-GSCs).The proliferative capacity of cells in the pGC-miR-124-GSCs group was significantly lower than that in the control cells (P＜0.05).CD133 positive rate was statistically decreased, the miR-124 expression was significantly increased, the A kt and RelA expressions were significantly decreased, and correspondingly the secretions of IL-1and IL-8 were significantly reduced in the pGC-miR-124-GSCs group as compared with those in the control group (P＜0.05).Conclusion MiR-124 overexpression induces GSCs differentiation and activates a strong anti-tumor ability, whose mechanism may be related to inhibition of inflammatory cytokine production.

BACKGROUND:In recent years,additive manufacturing(also known as 3D printing)has gradually become the mainstream method for producing titanium alloy brackets for removable partial dentures.Heat treatment,as an important method to improve the mechanical properties of 3D printed titanium alloys,has become a current hot topic of attention.OBJECTIVE:To summarize the main heat treatment technologies currently applied to 3D printed titanium alloy specimens(including annealing,solution aging,hot isostatic pressing,and other heat treatments)and their effects on the mechanical properties and microstructure of 3D printed titanium alloy specimens,providing a theoretical basis for improving the heat treatment technology of removable partial denture titanium alloy supports.METHODS:A computer search was conducted on research materials related to 3D printed titanium alloy heat treatment in databases such as CNKI,PubMed,and ScienceDirect.The search period was from 2012 to 2023.A total of 61 articles were selected based on inclusion and exclusion criteria.RESULTS AND CONCLUSION:(1)Using conventional annealing techniques to treat 3D printed titanium alloy specimens,keeping them at 500-900 ℃ for 2-4 hours,can effectively increase the elongation of 3D printed titanium alloy specimens.(2)Compared to conventional annealing techniques,solid solution aging treatment is more complex,and the titanium alloy specimens after solid solution aging treatment exhibit outstanding yield strength and better corrosion resistance.However,the 3D printed titanium alloy specimens after solid solution aging treatment have no advantage in terms of ductility.(3)Hot isostatic pressing treatment can reduce the internal defects of 3D printed titanium alloy specimens,significantly increase the elongation of 3D printed titanium alloy specimens,and increase their fatigue life.(4)Rapid heat treatment can significantly improve the elongation of 3D printed titanium alloy specimens,and the speed is faster.In terms of elongation improvement and heat treatment efficiency,it has more advantages than conventional annealing in the past.(5)The improvement of elongation of 3D printed titanium alloy specimens by cyclic heat treatment exceeds that of conventional annealing.Cyclic heat treatment can significantly improve the grain structure of 3D printed titanium alloy specimens,but the heat treatment time is too long and the efficiency is low.