NF-IL6 is an important transcriptional regulator of genes induced in activated monocytes/macrophages, and NF-IL6 is the only CCAAT/enhancer-binding protein (C/EBP) family member whose steady-state mRNA levels increase upon activation of monocytes (1). We show that increased transcription of the NF-IL6 gene is responsible, at least in part, for induction of NF-IL6 mRNA following activation of U9...

Stromal cell-derived factor-1 (SDF-1/CXCL12) is one of the essential chemokines, which mediates hematopoietic differentiations. However, the mechanism by which SDF-1 expression is regulated in granulocyte differentiation is poorly understood. Here, we suggest a novel mechanism by which all-trans-retinoic acid (ATRA) induces the expression of SDF-1 during the differentiation of promyelomonocytic...

Cytotoxicity and cell growth inhibition studies were performed for five distinct cobalt(ll) [Co(2)(acac)tpmc](ClO(4))(3), [Co(2)(dibzac)tpmc](ClO(4))(3), [Co(2)(hfac)tpmc](CIO(4))(2), [Co(2)(tmhd)tpmc](CIO(4))(3) and [Co(2)(ox)tpmc](CIO(4))(2).3H(2)0 and five molybdenum(Vl) complexes, [MoO(2)(pipdtc)(2)], [MoO(2)(morphdtc)], [MoO(2)(timdtc)(2)], [MoO(2)(pzdtc)(2)] and [MoO(2)(N-Mepzdtc)(2)]. Th...

We report that Xenopus laevis oocytes can efficiently translate and insert heterologous membrane receptors into the oocyte plasma membrane, where they can be detected by the binding of either monoclonal antibodies or ligands. Thus, oocytes injected with mRNA from the mouse J774 macrophage-like cell line, the rat RBL-1 basophilic leukemia, and the U937 promonocyte cell line, bound 2.4G2 Fab, rat...

Cdk9 is the catalytic subunit of TAK (cyclinT1/P-TEFb), a cellular protein kinase that mediates human immunodeficiency virus type 1 (HIV-1) Tat transcriptional activation function. To examine Cdk9 function in cells relevant to HIV-1 infection, we used a murine leukemia virus retrovirus vector to transduce and overexpress the cDNA of a dominant negative mutant Cdk9 protein (Cdk9-dn) in Jurkat T ...

In the course of screening for apoptotic substances that induce apoptosis in human leukemia U937 cells, a fungal strain, F000487, which exhibits potent inducible activity, was selected. The active compound was purified from an ethyl acetate extract of the microorganism by Sep-pak C18 column chromatography and HPLC, and was identified as atromentin by spectroscopic methods. This compound induced...

We evaluated real-time changes in extracellular acidification rates of human U937 and K562 leukemic cells treated with camptothecin or taxol. U937 cells treated with camptothecin or taxol for 30-60 min showed a continuous, irreversible decrease in extracellular acidification rate that was sensitive to amiloride. In contrast, U937 cells exposed to sodium azide showed an immediate, steep decrease...

BACKGROUND As the mechanism of macrophage activation is not well-understood, standardization of an assay system for measuring phagocytic activities of macrophages will be useful for research on macrophages. Previously, we established a novel standardized macrophage-activating factor (MAF) assay system using U937. MATERIALS AND METHODS Using the human monocytic cell line THP-1, another standar...

The human monoblastlike cell line U937 can be induced to differentiate by a variety of agents including y-interferon, phorbol esters, retinoic acid, and 1 ,25-dihydroxyvitamin D3 (VD3). Incubation of U937 with 1 to 1 .000 units of recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) did not induce macrophage differentiation. A synergistic effect on macrophage differentiat...

Epigallocatechin gallate (EGCG) is known to induce apoptosis in various types of tumor cells, but the precise mechanism by which EGCG induces apoptosis remains to be elucidated. The Fas-Fas ligand system is one of the major pathways operating in the apoptotic cascade. The aim of this study was to examine the possibility that EGCG-binding to Fas triggers the Fas-mediated apoptosis. The EGCG trea...