Phospholipase C (PLC)-mediated hydrolysis of membrane phospholipids results in the production of diacylglycerol, inositol phosphates, and choline metabolites. Inositol triphosphate increases calcium levels, while diacylglycerol activates protein kinase C. The present studies demonstrate that exogenous PLC generates inositol phosphates, releases choline metabolites, and activates protein kinase ...

Constituents of the bone marrow microenvironment have the capacity to influence both normal and malignant hematopoietic cell behavior. For example, HL-60 human promyelocytic leukemia cells in vitro display a more mature phenotype when grown on a bone marrow stroma-derived matrix. To elucidate which component(s) of the stromal matrix is capable of modulating HL-60 cell phenotype, matrices were t...

Diospyros kaki Thunb. (Ebenaceae) is widely distributed in North-East Asian countries. Almost all parts of this plant have been traditionally used as medicine. Human promyelocytic leukemia cells differentiate into monocytes or granulocytes when treated with 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] or all-trans retinoic acid (ATRA). Combination of low doses of ATRA or 1,25-dihydroxyvitamin D3 tha...

Mr 145,000 nucleolar protein antigen (p145) is associated with growing cells (R. L. Ochs et al., J. Cell Biol., 101: 211a, 1985) and has been found in a broad range of human cancers (J. W. Freeman et al., Cancer Res., 46: 3593-3598, 1986). In this study the presence of nucleolar antigen p145 was examined in the human promyelocytic tumor cell line HL-60 which was induced to differentiate by reti...

All-trans retinoic acid (ATRA) induces differentiation in various cell types and has been investigated extensively for its effective use in cancer prevention and treatment. Relapsed or refractory disease that is resistant to ATRA is a clinically significant problem. To identify the molecular mechanism that bridges ATRA differentiation and resistance in cancer, we selected the multidrug-resistan...

The human promyelocytic cell line, HL-60, shows large changes in endogenous poly(ADP-ribose) and in nuclear ADP-ribosyl transferase activity (ADPRT) during its induced myelocytic differentiation. DNA strand-breaks are an essential activator for this enzyme; and transient DNA strand breaks occur during the myelocytic differentiation of HL-60 cells. We have tested the hypothesis that these post-m...

Monocytotropic human immunodeficiency virus type 1 (HIV-1) isolates from patients with acquired immunodeficiency syndrome (AIDS) infect mononuclear phagocytes as well as activated T cells, but do not usually infect immature human myeloid cell lines in vitro. The HL-60 promyelocytic/myeloblastic cell line and the promonocytic line, U937, were susceptible to productive infection by monocytotropic...

Today’s medical word is highly dependent on severel natural products (e.g. taxol) in fighting different kinds of cancer and in constantly working to found new compounds. In this respect, 3-hydrogenkwadaphnin is a new diterpene ester isolated from Dendrostellera lessertii (Thymelaceae). It has been previously shown that this new compound has high anti-tumor activity and the capability of arresti...

Cellular transcription factors are important in the regulation of cellular genes. Recent studies have indicated that a class of cellular genes known as early response genes are important in the control of cellular growth properties. Two of these genes, c-jun and c-fos, play an important role in the control of cellular differentiation. Because the acute myelogenous leukemia cell line, HL-60, is ...

The bcl-2-proto-oncogene appears to contribute to the development of certain malignancies by inhibiting programmed cell death (apoptosis). Mature granulocytes show a markedly limited life span and rapidly undergo apoptosis. To further define the relationship between apoptosis and granulocyte differentiation, we used retroviral vector-mediated gene transduction to introduce the normal bcl-2 gene...