The fucose-binding lectin from Lotus tetragonolobus ( FBL -L) has been previously shown to bind specifically to normal cells of the myeloid and monocytic lineages. The purpose of this study was to explore the utility of fluoresceinated FBL -L as a leukemia differentiation marker in conjunction with a panel of other frequently used surface markers (Fc receptor, HLA-DR, OKM1, and antimonocyte ant...

Production of reactive oxygen species (ROS) by ischemic tissue after ischemia-reperfusion (I/RP) is an important factor that contributes to tissue injury. The small GTPase Rac1 mediates the oxidative burst, and ROS act on signaling pathways involved in expression of inflammatory genes. Because there is evidence implicating monocytes in the pathogenesis of I/RP injury, our objective was to deter...

Flavonoids, a vast group of polyphenols widely distributed in plants, are known to possess a range of biological activities and potential anti-tumor effects. X-linked inhibitor of apoptosis protein (XIAP) promotes the progression of leukemia by preventing tumor cells undergoing apoptosis. The present study investigated the potential effects and underlying mechanisms of pure total flavonoids fro...

AIMS The aim of the present study was to investigate the role of the Ras homolog family member A (RhoA)/Rho-associated coiled-coil-containing protein kinase 1 (ROCK1) signaling pathway in the inhibition of inflammatory responses by the glucocorticoid dexamethasone (Dex). METHODS The inhibitory effects of Dex and Rho-kinase inhibitor fasudil (Fas) on phorbol ester-induced release of O2(-) and ...

We have found that an anti-CD11c monoclonal antibody (MAb) inhibits the respiratory burst induced in phorbol 12-myristate 13-acetate (PMA)-differentiated U937 cells as well as in human peripheral blood monocytes and neutrophils upon cell stimulation with concanavalin A. The MAb had no effect, however, when the added stimulus was fMet-Leu-Phe or PMA. Flow cytometry analyses indicated that concan...

miR-302a have been reported to participate in various physiological and pathological processes, however, a role for miR-302a in etoposide (VP-16) resistance of acute myeloid leukemia (AML) has not been reported. In this study, the aberrant expression of miR-302a was analyzed in patients with AML and in the AML HL-60 and U937 cell lines. Overexpression of miR-302a, by targeting the 3'UTR of Rad5...

A function for protein kinase C(PKC), a member of the phorbol ester nonresponsive atypical protein kinase C subfamily, in modulating differentiation was examined in the leukemic U937 cell. Transfected U937 cells stably overexpressing PKCdisplayed a longer doubling time, lower saturation density at confluency, and an increase in adherence to plastic as compared to control cells. PKCcells express...

Treatment of U937 human monocyte-like cells with Streptococcus pyogenes led to an induction of apoptosis in these cells. A comparison between the wild-type strain and its isogenic protease-negative mutant indicated that the production of streptococcal pyrogenic exotoxin B (SPE B), a cysteine protease, caused a greater extent of apoptosis in U937 cells. Further study using purified SPE B showed ...

We analyzed the effect of recombinant human ¡nterleukin6 (IL-6), in combination with human recombinant interleukin la (IL-la), on the growth and differentiation of several human and mouse myeloid leukemic cell lines, specifically U937, HL-60, Ml, and its subclone Ml-3b-N, into macrophage-like cells. IL-6 and IL-1 inhibited the growth of U937, Ml, and Ml-3b-N in a dose-dependent manner. Treatme...

Three aspects of the involvement of tumor necrosis factor in human immunodeficiency virus (HIV) pathogenesis were examined. Tumor necrosis factor alpha (TNF-alpha) mRNA production was analyzed by polymerase chain reaction amplification in monocytic U937 cells and in a chronically HIV infected U937 cell line (U9-IIIB). TNF-alpha RNA was undetectable in U937 cells, whereas a low constitutive leve...