Objective To investigate the expression and possible function of tumor susceptibility gene 101 (TSG101) in multidrug-resistant cell lines of gastric cancer.Methods The expression of TSG101 was examined in gastric cancer cell line SGC7901 and its vincristine(VCR)-resistant subline SGC7901/VCR with semi -quantitative RT-PCR and Western blot. TSG101 eukaryotic expression vector was transfected into SGC7901 cells by lipofectamine TM 2000. The expression levels of TSG101 in SGC7901 and the transfectants were detected with Western blot. Fluorescence-activated cell sorting was applied to examine the cell cycle alteration and the intracellular mean fluorescence intensity of adriamycin (ADR). Growth curve and drug sensitivity of cells to VCR and ADR were analyzed by MTT assay.Results TSG101 was highly expressed in VCR resistant gastric cancer cells. The expression of TSG101 in TSG101 transfectants was up-regulated compared with that in SGC7901 transfected with empty vector or in SGC7901 cells. TSG101 transfectants were accumulated in S phase, with a concomitant decrease of cell population in G 1 phase. MTT assay showed that TSG101 transfectants proliferated rapidly and were more resistant to VCR and ADR than control cells. Conclusions The over-expression of TSG101 could promote the multidrug resistance phenotype of sGC7901 cells. TSG101 may play a certain role in multidrug resistance of gastric cancer.

Objective To study the expression of 9 delayed rectifier potassium channel subunits in human gastric cancer cell line AGS, as well as the effect of down-regulation of the expression of Kv1.5 on AGS cells proliferation. Methods RT-PCR technique was employed to detect the mRNA expression of Kv1.1, Kv1.2, Kv1.3, Kv1.5, Kv1.6, Kv2.1, Kv2.2, Kv3.1 and Kv3.2 in AGS cells. Once the expression of Kv1.5 protein was confirmed by immunofluorescence, small interference RNA (siRNA) was applied to down-regulate the Kv1.5 protein expression, then MTT assay and flow cytometry were used to observe the cell proliferation and the cell cycle distribution. Results Totally 7 delayed rectifier potassium channel subunits were detected in AGS cells, among them the mRNA levels of Kv1.3, Kv1.5 and Kv2.1 were much higher than that of the others. It was confirmed by immunofluorescence that the Kv1.5 protein was expressed mainly in AGS cytomembrane. After the endogenous Kv1.5 expression in AGS cells was down regulated by siRNA, the cell proliferation obviously slowed down and the cell growth stopped in G1 period. Conclusion Multiform expression of delayed rectifier potassium channel subunits existed in AGS cells, and Kv1.5 may be involved in the regulation of gastric carcinoma cell proliferation by modulating the cell cycle.

An electrochemiluminescence (ECL) sensor with molecularly imprinted polymer (MIP) film was prepared for the determination of heroin. The sensor was prepared by re-modifying the molecular imprinting membrane onto the Ru ( bpy ) 2+3 modified glassy carbon electrode. The electrochemical and electrochemiluminescence behavior of the sensor was investigated. The proposed sensor displayed high sensitivity and excellent selectivity for the target molecule heroin. Under the optimum conditions (0. 1 mol/ L PBS (pH 7. 0) at a scan rates of 100 mV/ s and incubation time of 5 min), a linear response was observed with the concentrations of heroin from 1. 0 × 10-14 mol/ L to 1. 0 ×10-10 mol/ L and the detection limit was 4. 0 × 10-15 mol/ L. The sensor was successfully applied to the determination of heroin in urineand saliva samples with the recoveries from 97% to 104% .

Objective To investigate the retardation effect of voltage gated potassium channel Kv1 5 on growth of gastric cancer cells SGC7901. Methods By using restriction enzymes of Hind Ⅲ and Kpn I, cDNA encoding Kv1 5 was reversely constructed into eukaryotic expression vector pcDNA3 1. SGC7901 cells were transfected with the recombinants using LipofectAMINE2000. Stable clones of transfectants were obtained after selection by G418 The growth of cells was monitored by cell growth curve and cell colony formation. The effect of Kv1 5 protein on cell cycle was examined by flow cytometry. Expression of Cyclin D1 protein was detected by Western blot. Results The antisense was found to effectively inhibit the expression of Kv1 5 protein in the transfectants. The growth and colony formation of transfectants were significantly reduced as compared with controls. The cell cycle review showed retardation of transfectants with Kv1 5 antisense in the G 1 phase. Expression of Cyclin D1 protein was decreased in Kv1 5 antisense transfectants. Conclusion The antisense of Kv1 5 has effect of retardation on growth of gastric cancer cells SGC7901

OBJECTIVETo generate phage-displayed anti-idiotypic antibody single chain variable fragments (anti-Id ScFv) to MG7 monoclonal antibody (McAb) directed against gastric carcinoma so as to lay a foundation for developing anti-Id ScFv vaccine of the cancer.

METHODSBalb/c mice were immunized i.p. with MG7 McAb conjugated with keyhole limpet hemocyanin (KLH), and mRNA was isolated from the spleens of the immunized mice. Heavy and light chain (VH and VL) genes of antibody were amplified separately and assembled into ScFv genes with a linker DNA by PCR. The ScFv genes were ligated into the phagemid vector pCANTAB5E and the ligated sample was transformed into competent E. coli TG1. The transformants were infected with M13K07 helper phage to yield recombinant phages displaying ScFv on the tips of M13 phage. After 4 rounds of panning with MG7, the MG7-positive clones were selected by ELISA from the enriched phages. The types of the anti-Id ScFv displayed on the selected phage clones were preliminarily identified by competition ELISA.

RESULTSThe VH, VL and ScFv DNAs were about 340 bp, 320 bp and 750 bp respectively. Twenty-four MG7-positive clones were selected from 60 enriched phage clones, among which 5 displayed beta or gamma type anti-Id ScFv.

CONCLUSIONThe anti-Id ScFv to MG7 McAb can be successfully selected by recombinant phage antibody technique, which paves a way for the study of prevention and cure of gastric carcinoma by using anti-Id ScFv.

Animals ; Antibodies, Anti-Idiotypic ; biosynthesis ; genetics ; Antibodies, Monoclonal ; genetics ; immunology ; Bacteriophages ; genetics ; Cloning, Molecular ; Immunoglobulin Fragments ; biosynthesis ; genetics ; Immunoglobulin Heavy Chains ; biosynthesis ; genetics ; Immunoglobulin Light Chains ; biosynthesis ; genetics ; Immunoglobulin Variable Region ; biosynthesis ; genetics ; Mice ; Mice, Inbred BALB C ; RNA, Messenger ; genetics ; Stomach Neoplasms ; immunology ; Vaccines, DNA ; genetics ; immunology

Transjugular intrahepatic portosystemic shunt (TIPS) is a safe and effective method for the treatment of portal hypertension complications in patients with decompensated liver cirrhosis. At present, there are many prognostic scoring tools for risk stratification of poor prognosis after TIPS. This article briefly introduces seven prognostic scoring tools commonly used for TIPS and summarizes the clinical research evidence of each scoring tool. The literature review shows that there is currently no sufficient research evidence to determine the optimal prognostic scoring tool after TIPS. Future clinical studies should comprehensively explore the advantages and disadvantages of different scoring tools in predicting short- and long-term adverse prognostic events after TIPS and develop new prognostic scoring tools in combination with new prognostic markers.