OBJECTIVETo investigate the effects of lentivirus-mediated RNA interference targeting vascular endothelial growth factor receptor 1 (VEGFR1) gene on the proliferation, migration and apoptosis of leukemic cell line U937.

METHODSShort hairpin RNAs (shRNA) targeting VEGFR-1 was synthesized and cloned into pRNAT-U6.2 lentiviral vector. The expression vectors were transfected into 293T cell line to produce packaged lentivirus. After infected with the packaged lentivirus, the expression of VEGFR-1 gene of U937 cells at mRNA and protein level was detected by real-time PCR and Western blot. VEGF production by the cells was determined by ELISA. Cell proliferation and survival under regular culture and in the presence of cytarabine (Ara-C) was determined by CCK-8 assay. Migration assays were performed by 5 µm pore transwell inserts.

RESULTSThe lentiviral shRNA vector targeting VEGFR-1 was successfully constructed and transfected into U937 cells. The shRNA vector effectively inhibited the expression of VEGFR-1 gene in U937 cell line at mRNA and protein levels. As compared to that of the control, the proliferation rate of U937-shVEGFR-1 cells reduced; The VEGF production and migrated cell number of U937-shVEGFR-1 cells decreased dramatically. After treated with Ara-C, the inhibition rate and apoptotic rate of U937-shVEGFR-1 cells increased significantly. The number of migrated cells in the KD group under regular culture and in the presence of VEGF was markedly lower than that in the NC group and CON group. Bevacizumab could decrease the number of migrated cells in the NC group and CON group, but could not in the KD group.

CONCLUSIONSLentivirus-mediated RNA interference targeting VEGFR1 gene reduces the proliferation, migration of U937 cell line and enhances its sensitivity to Ara-C.