lipopolysaccharide effect on vascular endothelial factor and matrix metalloproteinases in leukemic cell lines in vitro

Background: angiogenesis, the process of new vessels generation, plays a critical role in tumor invasion and metastasis. vascular endothelial growth factor (vegf), as a cytokine, and matrix metalloproteinases (mmps), has been the important factors that involved in angiogenesis. lipopolysaccharide (lps) has an essential effect on angiogenesis. objectives: in this study the effect of lps on vegf production and mmp-2/mmp-9 activity in two leukemic cell lines has been assessed in vitro. materials and methods: human leukemic u937 and thp1 cells were cultured in complete rpmi medium. then the cells at the exponential growth phase were incubated with different concentrations of lps (0 - 4 μg/ml) for 48 hours. then the level of vegf production and mmp-2/mmp-9 activity in cell culture supernatants were evaluated with the elisa standard kits and gelatin zymography respectively. results: u937 cells have produced a large amount of vegf without any stimulus and lps has not shown any substantial effect on vegf production by these cells. however thp1 cells have produced a small amount of vegf without stimulation and lps significantly has increased vegf production in these cells dose-dependently. moreover lps significantly has augmented the mmp-2/mmp-9 activity in the both leukemic cell lines in a dose-dependent manner. conclusions: our results have shown that lps might be a potential inducer/enhancer of vegf production and mmp-2/mmp-9 activity (angiogenic factors) in leukemia. moreover the lps effect on angiogenesis might be in part, due to its stimulatory effects on vegf and mmps. overall lps-stimulated leukemic cells might be good models for study and planning the useful therapeutic approaches for angiogenesis- dependent diseases.