Nanocomposite-siRNA approach for down-regulation of VEGF and its receptor in myeloid leukemia cells.

ABSTRACT

BACKGROUND: Efficient modulation of aberrant vascular endothelial growth factor (VEGF) and its receptor-1 (Flt-1) expressions have become a potential therapeutic strategy for hematologic malignancies including myeloid leukemia. In this study, we explored the safety and efficacy of chitosan nanoparticle siRNA-VEGF and Flt-1 in leukemic U973 cells. METHODS: Cell transfection efficiencies were analyzed by fluorescence microscope, quantitative Real Time PCR; cell growth inhibitory rates were analyzed by CCK-8 assays and flow cytometry. RESULTS: siRNA-coated chitosan nanosphere transfection led to 65%, Lipofectamine 2000 to 50% and adenovirus to 90% transfection efficiencies. Three days after transfection of U973 cells, the siRNA induced gene silencing rates of VEGF and Flt-1 were 68% and 65% in the adenovirus, 45% and 43% in the chitosan nanoparticle group. The cell growth inhibitory rates were 34.73% for VEGF and 27.61% for Flt-1 silencing in the adenovirus and 27.04% for VEGF and 21.49% for Flt-1 silencing in the chitosan nanoparticle group. CONCLUSION: Chitosan nanoparticle siRNA technology can effectively inhibit the expression of VEGF and its receptor in leukemic cells, which led to suppression of their proliferation. Though less efficient than adenoviruses, their non-viral properties suggest that chitosan nanoparticle siRNA complex gene silencing is suitable for further trials.