Objective To construct recombinant adenovirus vector containing mouse CD40Ig fusion gene for the study of induction of donor-specific tolerance. Methods CD40Ig fusion gene was constructed by PCR overlapping technique, and was cloned into the shuttle plasmid pAdTtrack-CMV. The linearized shuttle plasmid was co-transfected into the E.coli strain BJ5183 with bone plasmid pAdeasy1, then the recombinant adenovirus plasmid was generated. The adenovirus was packaged and amplified in Cells 293. Results The recombinant virus AdCD40Ig was successfully constructed and its titer was 5?109 efu/ml. Conclusion AdCD40Ig can be used as an agent in experiment to induce donor-specific tolerance.

Objective To investigate the suppression of mrp1 and MRP1 induced by small interfering RNA and the restoration of sensitivity to chemotherapeutic drugs in the multidrug-resistant hepatocellular carcinoma cell lines HepG2/mrp1. Methods mrp1-targeted small interfering RNA duplexes were designed and composed and introduced into multidrug-resistant hepatocellular carcinoma cell lines HepG2/mrp1. The suppression of mrp1 mRNA and its gene product MRP1 was examined by RT-PCR and flow cytometry (FCM), respectively. MTT assay was performed to measure the reverse effect of small interfering RNA based on the results of ICs0. Results The overexpression of mrp1 mRNA and MRP1 was effectively suppressed by small interfering RNAs. The level of mrp1 mRNA in the transfected HepG2/mrp1 cells was reduced to (86.36±2.76)% and MRP1 to (89.38±3.76)%compared with those of the controls. The resistance to ADR was reversed five-fold, which indicated the restoration of sensitivity to drugs. Conclusion Small interfering RNA can inhibit mrp1 expression effectively and reverse the multidrug resistance mediated by MRP1.

The fragment of MDR1 gene obtained from the plasmid pHaMDR1-1 carrying the whole human MDR1 cDNA, was cloned reversely into the shuttle plasmid pAdTrack-CMV. With the resultant plasmid and the backbone plasmid pAdEasy-1, the homologous recombination took place in the Escherichia coli BJ5183 and the recombinant adenoviral plasmid was generated. The adenoviruses were packaged in the 293 cells. The recombinant adenovirus MDR1 vector would introduce the antisense MDR1 gene into the human multidrug resistance hepatocellular cell line effectively, which would provide an experimental basis for studies on the multidrug resistance in human hepatocellular carcinoma.
ATP-Binding Cassette, Sub-Family B, Member 1 ; biosynthesis ; genetics ; Adenoviridae ; genetics ; metabolism ; Carcinoma, Hepatocellular ; drug therapy ; genetics ; Cell Line, Tumor ; Drug Resistance, Neoplasm ; genetics ; Escherichia coli ; genetics ; Gene Transfer Techniques ; Genes, MDR ; genetics ; Genetic Vectors ; Humans ; Liver Neoplasms ; drug therapy ; genetics ; Multidrug Resistance-Associated Proteins ; biosynthesis ; genetics ; Oligonucleotides, Antisense ; pharmacology ; Plasmids ; Recombinant Proteins ; biosynthesis ; genetics ; Recombination, Genetic

Tryptophan 2,3-dioxygnease 2 (TDO2) is specific for metabolizing tryptophan to kynurenine (KYN), which plays a critical role in mediating immune escape of cancer. Although accumulating evidence demonstrates that TDO2 overexpression is implicated in the development and progression of multiple cancers, its tumor-promoting role in esophageal squamous cell carcinoma (ESCC) remains unclear. Here, we observed that TDO2 was overexpressed in ESCC tissues and correlated significantly with lymph node metastasis, advanced clinical stage, and unfavorable prognosis. Functional experiments showed that TDO2 promoted tumor cell proliferation, migration, and colony formation, which could be prevented by inhibition of TDO2 and aryl hydrocarbon receptor (AHR). Further experimentation demonstrated that TDO2 could promote the tumor growth of KYSE150 tumor-bearing model, tumor burden of C57BL/6 mice with ESCC induced by 4-NQO, enhance the expression of phosphorylated AKT, with subsequent phosphorylation of GSK3