Patterns of Vascular Endothelial Growth Factor Expression in Hematopoietic Malignant Cells

Vascular endothelial growth factor (VEGF) is a cytokine which is overexpressed in many malignant cancers including leukemia. VEGF plays an important role in tumor invasion and metastasis. Determination of the pattern of VEGF expression in human leukemic cell lines could be useful not only in screening of new antileukemic agents but also to study the mechanism of their action. In the present study, the pattern of VEGF production in some human leukemic cell lines has been assessed in vitro. Three human leukemic cell lines (Molt-4, Jurkat and U937) were used in this study. The cells were cultured in complete RPMI medium and then incubated with different concentrations of phorbolmyristate acetate (PMA) or phytoheamagglutinin (PHA) for 48 hours. The level of VEGF secreted in the cellculture supernatants were measured with enzyme-linked immunosorbent assay kits (R and D systems). U937 cells produced a large amount of VEGF without any stimulus and PHA/PMA did not show any substantial effect on VEGF production by U937 cells. However, Molt-4 and Jurkat cells, produced VEGF less than U937 when cultured alone (with no stimulation) and PMA/PHA significantly increased the VEGF production in these cells dose-dependently. Different patterns of VEGF expression were shown in different leukemic cell lines (Molt-4, Jurkat and U937) used in this study. These cells could be useful tools for screening of VEGF modulators and so for planning of new drugs for treatment of leukemia and other VEGF related disorders.