[Inhibition of leukemic cell proliferation by human soluble VEGF-R1]

The current study was purposed to investigate the inhibitory effect of human soluble vascular endothelial growth factor-1 (sFLT-1) on the proliferation of leukemic cells in vitro. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the VEGF mRNA and VEGF-R1 (FLT-1) mRNA in K562, HL60, U937 leukemic cell lines and bone marrow LTC-IC. Flow cytometry was used to detect the VEGF and VEGF-R1 (FLT-1) in all above-mentioned cells. VEGF concentrations in the cell culture supernatants were determined by enzyme-linked immunosorbent assay (ELISA). Cell proliferation was determined by MTT after adding sFLT-1 to K562, HL60 and LTC-IC culture system. The result showed that expression of VEGF could be detected in K562, HL60, U937 leukemic cell lines and LTC-IC, especially K562, K562 and HL60 cell lines also expressed FLT-1, but a little expression was found in U937 and LTC-IC. sFLT-1 could effectively inhibit the growth of K562 and HL60 cell lines in dose-dependent manner. The highest inhibition rate was found at 48 hours after adding sFLT-1. It is concluded that sFLT-1 can inhibit the growth of some leukemic cell lines, and the inhibition effect enhances as the concentration of the sFLT-1 increase, but sFLT -1 not influence the proliferation of normal marrow cells.