Suppression of scinderin modulates epithelial­mesenchymal transition markers in highly metastatic gastric cancer cell line SGC­7901.

Scinderin is a Ca2+­dependent filamentous actin (F­actin) severing and capping protein, which has a key role in regulated secretion. However, little is known regarding the function and mechanism of scinderin in human carcinoma development and progression. In the present study, the biological function of scinderin was investigated using a cell proliferation assay, flow cytometric analysis and a Transwell assay in highly tumorigenic and the metastatic human gastric cancer cell line SGC­7901 transfected with scinderin­small hairpin RNA lentivirus. The changes in the expression of epithelial­mesenchymal transition (EMT) markers were also investigated. The results indicated that scinderin knockdown effectively suppressed proliferation, reduced migration and arrested the cell cycle of the SGC­7901 cells at G2/M phase. Furthermore, scinderin knockdown altered the expression of EMT markers; the expression of E­cadherin was significantly upregulated, along with an evident decrease in N­cadherin and ß­catenin expression. In conclusion, the present study suggested that suppression of scinderin impaired proliferation and migration of gastric cancer SGC­7901 cells and attenuates its EMT process. Scinderin may therefore be a potential target for tumor EMT and therapy against gastric cancer.

[Relationship between drug resistance of Pseudomonas aeruginosa isolated from burn wounds and its mobile genetic elements].

OBJECTIVE: To investigate the relationship between the drug resistance of Pseudomonas aeruginosa (PA) isolated from burn patients wounds and its mobile genetic elements, including plasmid, transposon, and integron. METHODS: Thirty-two strains of PA were isolated from wounds exudate of hospitalized burn patients in Ningbo No. 2 Hospital. PA drug sensitivity was determined using GNS-448 drug sensitivity card and K-B tests. The genetic markers of plasmid, transposon and integron including traA, traF, tnpA, tnpU, merA, int I 1 were amplified by PCR and verified by gene sequencing. RESULTS: Drug resistant rate of 32 PA strains to gentamicin, amikacin, cefoperazone/sulbactam, ciprofloxacin was 43.7%, 32.0%, 46.8%, 49.9%, respectively. PA drug resistant rates to piperacillin, cefotaxime, ceftazidime, cefepime, aztreonam, piperacillin/tazobactam, levofloxacin, imipenem and meropenem were all above 56.0%. Seventeen out of 32 PA strains were found to carry transposon and (or) integron genetic markers. One strain was positive for both tnpA and merA, 8 strains were positive for both merA and int I 1, 1 strain was only positive for tnpA, 2 strains were only positive for merA, and 5 strains were positive for int I 1 only. CONCLUSIONS: PA isolated from burn wounds of hospitalized patients in Ningbo No. 2 Hospital is seriously drug resistant, which may relate with its high positive rate of mobile genetic elements of transposon and (or) integron.

[Interaction between polysaccharides and interferon-gamma using an improved ELISA approach].

OBJECTIVE: To establish an ELISA approach to study the interaction of polysaccharides with cytokine in vitro. METHODS: The heparin BSA complexes (HBC) were synthesized with a chemistry method and separated using a 1 X 90 cm column of Separose 4B. After identification of the complex via SDS-PAGE,the wells of ELISA plates were coated with HBC and the interaction of HBC with interferon-gamma (IFN-gamma) was detected. The effects of heparin, low molecular weight heparin (LMW heparin), chondroitin sulfate (CS), hyaluronic acid (HA) and carrageenans on the binding of HBC to IFN-gamma were tested in this system. RESULT: Human recombinant IFN-gamma bound to heparin in a concentration dependent manner, the binding of IFN-gamma to HBC was detected at the concentration of 0.25 ng, and saturated at around 2 ng. Free heparin, LMW heparin, CS,HA and carrageenans competed for the binding of IFN-gamma to HBC with significant different ability. The IC(50)concentrations of heparin and LMW heparin were 2.40 microg/ml and 18.60 microg/ml respectively. CONCLUSION: IFN-gamma is a cytokine with high binding affinity to heparin and carrageenans family but poor to CS-A and CS-C. ELISA is a simple, sensitive approach to detect the interaction of polysaccharides with cytokine in vitro.