Conditioned medium from cultures of HL-60 myeloid leukemia cells grown on extracellular bone marrow matrix induces macrophage-like differentiation of fresh HL-60 cells. The active medium component is sensitive to protease treatment, indicating that it is a protein, but it is heat stable. Conditioned medium from HL-60 cells grown on protease-treated bone marrow matrix still contains the active c...

All-trans retinoic acid (ATRA) is one of the most useful drugs in the treatment for acute promyelocytic leukemia (APL), but its adverse effects, which include drug resistance and hypercalcemia are obstacles to achieving complete remission. Our previous study showed that some sesquiterpene lactones (STLs), i.e., helenalin (HE) and parthenolide (PA) but not sclareolide (SC), enhance ATRA-induced ...

Objective—The purpose of this study was to evaluate the role of membrane cholesterol on human neutrophil and HL-60 biomechanics, capture, rolling, and arrest to P-selectin– or IL-1–activated endothelium. Methods and Results—Methyl-cyclodextrin (M CD) removed up to 73% and 45% of membrane cholesterol from HL-60 cells and neutrophils, whereas M CD/cholesterol complexes resulted in maximum enrichm...

Adherence reactions involving human leukocytes are mediated by a family of glycoprotein surface antigens composed of three different alpha subunits designated alpha L, alpha M, and alpha X, each of which is associated with a single beta subunit in an alpha 1 beta 1 heterodimer structure. We cloned the cDNA for the common beta subunit and investigated beta subunit mRNA expression in HL-60 promye...

To better define the role of glutathione (GSH) in cell differentiation, the present study measured GSH concentrations during terminal HL-60 cell differentiation, in the presence and absence of differentiation-inducing agents, and in the presence and absence of GSH altering agents. Interestingly, there was a small transient increase in intracellular GSH levels during dimethyl sulfoxide (DMSO) or...

OBJECTIVE The purpose of this study was to evaluate the role of membrane cholesterol on human neutrophil and HL-60 biomechanics, capture, rolling, and arrest to P-selectin- or IL-1-activated endothelium. METHODS AND RESULTS Methyl-beta-cyclodextrin (MbetaCD) removed up to 73% and 45% of membrane cholesterol from HL-60 cells and neutrophils, whereas MbetaCD/cholesterol complexes resulted in ma...

In order to determine if cyclic adenosine 3':5'-monophosphate(cyclic AMP)-dependent protein kinase has a role in the expression of chemically induced differentiation of HL-60 cells, levels and subcellular distribution of this enzyme were studied during this process. Cyclic AMP binding protein and stimulated kinase activities increased moderately in cytosol and more mark edly in nucleosol and no...

In order to determine if cyclic adenosine 3':5'-monophosphate- (cyclic AMP)-dependent protein kinase has a role in the expression of chemically induced differentiation of HL-60 cells, levels and subcellular distribution of this enzyme were studied during this process. Cyclic AMP binding protein and stimulated kinase activities increased moderately in cytosol and more markedly in nucleosol and n...

Topoisomerase II (topo II), an enzyme essential for cell viability, is present in mammalian cells as the aand b-isoforms. In human leukemia HL-60/S or HL-60/doxorubicin (DOX)0.05 cells, the levels of topo IIaor b-protein were similar in either asynchronous exponential or synchronized cultures. Although topo IIa was hypophosphorylated in HL-60/DOX0.05 compared with HL-60/S cells, both overall an...