This study investigated the intracellular localization of asparagine synthetase (ASNS) in the relation with chemoresistance in leukemia. pIRES-GFP-ASNS-Flag/Neo expression vector was transiently tansfected into SK-N-MC cells and 297T cells respectively. Immunofluorescence and Western blot analysis were performed for cellular localization of ASNS respectively. U937 cells were treated with L-asparaginase for 48 h and examined for endogenous ASNS expression on plasma membrane by immunofluorescence staining. Immunofluorescence staining showed that the transiently expressed ASNS was partly localized on transfected-SK-N-MC cell surface. Moreover, Western blotting exhibited that ASNS expressed both in cytosol and on plasma membrane of transfected-293T cells. Immunofluorescence staining with anti-ASNS-specific monoclonal antibody revealed that endogenous ASNS was localized on the plasma membrane of U937 cells, except for its distribution in the cytosol. In addition, ASNS exhibited a higher expression on plasma membrane after treatment with L-asparaginase as compared with the untreated cells. It was concluded that the subcellular translocation of ASNS may play an important role in L-asparaginase resistance in leukemia cells.

The nanoparticle-modified surfaces were built up by alternating deposition of oppositely charged Al2O3 and SiO2 nanoparticles (from 10 nm to 500 nm) solutions. The properties of these nanoparticle-modified surfaces and the controls were investigated by Atomic Force Microscope for topography analysis. Pseudomonas Fluorescence (PF) cell adhesion was evaluated by microscopic determination of the numbers of cells that adhered to the produced slides exposed to PF cell suspensions on static and dynamic condition. The results show that adhesion of PF to both surfaces readily increases with the time of exposition but the adhered numbers of PF on produced surfaces are considerably higher than that on controls in static condition. Cell morphologies on these nanoparticle-modified surfaces studied by inverted microscope show that the adhered PF on the produced surfaces are more in presence of clusters, which contributes more to the total adhering numbers in the late of cell adhesion assays. Meanwhile on controls the cells rarely attained confluence and had a single shape. The significant statistical correlation observed between nanoparticle-modified surfaces and control adds a new concept to the studies of substratum topography influence on cell behavior. The results suggest that nanoparticle-modified surfaces may enhance the interactions between PF cell and slides.
Bacterial Adhesion ; Fluorescence ; Nanoparticles ; Pseudomonas ; cytology ; Silicon Dioxide ; Surface Properties

This study investigated the intracellular localization of asparagine synthetase (ASNS) in the relation with chemoresistance in leukemia.pIRES-GFP-ASNS-Flag/Neo expression vector was transiently tansfected into SK-N-MC cells and 297T cells respectively.Immunofluorescence and Western blot analysis were performed for cellular localization of ASNS respectively.U937 cells were treated with L-asparaginase for 48 h and examined for endogenous ASNS expression on plasma membrane by immunofluorescence staining.Immunofluorescence staining showed that the transiently expressed ASNS was partly localized on transfected-SK-N-MC cell surface.Moreover,Western blotting exhibited that ASNS expressed both in cytosol and on plasma membrane of transfected-293T cells.Immunofluo-rescence staining with anti-ASNS-specific monoclonal antibody revealed that endogenous ASNS was localized on the plasma membrane of U937 cells,except for its distribution in the cytosol.In addition,ASNS exhibited a higher expression on plasma membrane after treatment with L-asparaginase as compared with the untreated cells.It was concluded that the subcellular translocation of ASNS may play an important role in L-asparaginase resistance in leukemia cells.