title: Augmentation of retinoic acid-induced granulocytic differentiation in HL-60 leukemia cells by serine/threonine protein phosphatase inhibitors.
abstract: To evaluate the involvement of protein phosphatases (PP) in differentiation of human myelogenous leukemia HL-60 cells, we made use of potent inhibitors of PP1 and PP2A, calyculin-A (CAL-A) and okadaic acid (OKA). CAL-A and OKA could augment all-trans retinoic acid (ATRA)-induced granulocytic differentiation, whereas the differentiation toward macrophage lineage by 12-o-tetradecanoylphorbol acetate (TPA) was unchanged in the presence of CAL-A. CAL-A augmented the phosphorylation of 18K, 23K and 30K proteins induced by ATRA. The PP1 and PP2A were identified and were present mainly in the cytosol of HL-60 cells. These results suggest that either PP1 or PP2A or both may be involved in regulating granulocytic differentiation of HL-60 cells.
authors.affiliation: First Department of Internal Medicine, Mie University School of Medicine, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Morita
authors.forename: M
authors.initials: M
authors.lastname: Nishikawa
authors.forename: K
authors.initials: K
authors.lastname: Kobayashi
authors.forename: K
authors.initials: K
authors.lastname: Deguchi
authors.forename: M
authors.initials: M
authors.lastname: Ito
authors.forename: T
authors.initials: T
authors.lastname: Nakano
authors.forename: H
authors.initials: H
authors.lastname: Shima
authors.forename: M
authors.initials: M
authors.lastname: Nagao
authors.forename: T
authors.initials: T
authors.lastname: Kuno
authors.forename: C
authors.initials: C
authors.lastname: Tanaka
mesh_terms: D002448:Cell Adhesion; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D002847:Chromatography, Agarose; D004988:Ethers, Cyclic / Q000494:pharmacology; D006098:Granulocytes / Q000166:cytology*; D006801:Humans; D007938:Leukemia; D008264:Macrophages / Q000166:cytology; D008387:Marine Toxins; D019319:Okadaic Acid; D010080:Oxazoles / Q000494:pharmacology; D010749:Phosphoprotein Phosphatases / Q000037:antagonists & inhibitors / Q000502:physiology*; D010766:Phosphorylation; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014212:Tretinoin / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D004988:Ethers, Cyclic; D008387:Marine Toxins; D010080:Oxazoles; D019319:Okadaic Acid; D014212:Tretinoin; C059041:calyculin A; D010749:Phosphoprotein Phosphatases; D013755:Tetradecanoylphorbol Acetate