Induction of CD14 Expression and Differentiation to Monocytes or Mature Macrophages in Promyelocytic Cell Lines: New Approach.

PURPOSE: CD14, one of the main differentiation markers on the surface of myeloid lineage cells, acts as a key role in activation of LPS-induced monocytes. LPS (lipopolysaccharide) binds to LPS-binding protein in plasma and are delivered to the cell surface receptor CD14. In this study, Various stimuli [Dimethyl Sulfoxide (DMSO), active 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] and LPS], either alone or in combination, have been recognized that have an effect on the level of CD14 expression in the human HL-60 and U937 promonocytic cell lines and therefore induce their terminal differentiation into monocytes or mature macrophages. METHODS: U937 and HL-60 cells were cultured in RPMI 1640 supplemented with 10% FBS. For each cell line, 1Ã106 cells were seeded for 72 hours with DMSO, 14 days with LPS and 18 days with 1, 25-D3 in each well plate; then ELISA method was used to study their responses to the factors by means of anti-CD14. RESULTS: ELISA assay demonstrated that U937 and HL-60 cells were induced by both [1,25(OH)2D3] and DMSO to obtain characteristics of adherent cells and express CD14 protein; moreover, LPS at a low dose increased CD14 expression on surface of this cells. CONCLUSION: According to the our results, it is speculated that CD14 gene expression may be induced in human U937 and HL-60 cell lines by different factors including 1,25-D3, DMSO and LPS.

In vitro Cytotoxic Activity of Four Plants Used in Persian Traditional Medicine.

PURPOSE: The aim of this study was to investigate in vitro cytotoxic activity of four methanolic crude plant extracts against panel cell lines. METHODS: Methanolic extracts were tested for their possible antitumor activity and cytotoxicity using the 3-(4,5-dimetylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay on six cancer cell lines; non-Hodgkin's B-cell lymphoma (Raji), human leukemic monocyte lymphoma (U937), human acute myelocytic leukemia (KG-1A), human breast carcinoma (MCF-7 cells), human Prostate Cancer (PC3) and mouse fibrosarcoma (WEHI-164) cell lines and one normal cell line; Human Umbilical Vein Endothelial Cells (HUVEC). RESULTS: All species showed dose dependent inhibition of cell proliferation. IC50 values ranging from 25.66±1.2 to 205.11±1.3 µg/ml. The highest cytotoxic activity Chelidonium majus L> Ferulago Angulata DC> Echinophora platyloba DC> Salvia officinalis L, respectively. CONCLUSION: all extracts demonstrate promising cytotoxicity activity as a natural resource for future bio-guided fractionation and isolation of potential antitumor agents.