Construction and characterization of a eukaryotic expression vector for small interfering RNA targeting the NEDD9 gene

Effects of lentivirus-mediated RNAi knockdown of NEDD9 on human lung adenocarcinoma cells in vitro and in vivo

The aim of the present study was to investigate the biological behavior of lung adenocarcinoma A549 cells following transfection with NEDD9-specific lentiviral particles in vitro and in vivo. NEDD9-specific lentiviral particles were chemically synthesized and transfected into the human lung adenocarcinoma A549 cell line. NEDD9 mRNA and protein levels were determined by fluorescence quantitative RT-PCR and western blotting. Cell proliferation was evaluated using soft agar colony formation assays and flow cytometric analysis. Migration and invasion were evaluated by wound-healing and transwell assays and xenograft animal models. Transfection was successful, and expression levels of NEDD9 mRNA and protein in the lentivirus-NEDD9-siRNA group were downregulated. As indicated by soft agar colony formation assays, the number of clones in the siRNA group were significantly lower than the number of colonies in the blank and negative control groups (P<0.01). In addition, the percentage of cells in the S phase in the siRNA group was significantly lower than the percentages in the blank and negative control groups (P<0.05). Furthermore, as detected by cell migration and invasion assays, values of wound healing were increased and the number of invading cells were decreased in the siRNA group (both P<0.05). We also showed that lentivirus-mediated NEDD9-siRNA decreased the growth potential of subcutaneous A549 xenografts in vivo. These data imply that knockdown of the NEDD9 gene results in suppression of tumor cell proliferation, migration, invasion and cell growth in vitro and in vivo. Lentivirus-mediated NEDD9-siRNA may have potential therapeutic utility for human lung adenocarcinoma.

Binding of a protein or a small polyelectrolyte onto synthetic vesicles

Catanionic vesicles were prepared by mixing nonstoichiometric amounts of sodium bis(2-ethylhexyl) sulfosuccinate and dioctyldimethylammonium bromide in water. Depending on the concentration and mole ratios between the surfactants, catanionic vesicular aggregates are formed. They have either negative or positive charges in excess and are endowed with significant thermodynamic and kinetic stability. Vesicle characterization was performed by dynamic light scattering and electrophoretic mobility. It was inferred that vesicle size scales in inverse proportion with its surface charge density and diverges as the latter quantity approaches zero and/or the mole ratio equals unity. Therefore, both variables are controlled by the anionic/cationic mole ratio. Small-angle X-ray scattering, in addition, indicates that vesicles are unilamellar. Selected anionic vesicular systems were reacted with poly-L-lysine hydrobromide or lysozyme. Polymer binding continues until complete neutralization of the negatively charged sites on the vesicles surface is attained, as inferred by electrophoretic mobility. Lipoplexes are formed as a result of significant electrostatic interactions between cationic polyelectrolytes and negatively charged vesicles.