title: A PU.1 suppressive target gene, metallothionein 1G, inhibits retinoic acid-induced NB4 cell differentiation.
abstract: We recently revealed that myeloid master regulator SPI1/PU.1 directly represses metallothionein (MT) 1G through its epigenetic activity of PU.1, but the functions of MT1G in myeloid differentiation remain unknown. To clarify this, we established MT1G-overexpressing acute promyelocytic leukemia NB4 (NB4MTOE) cells, and investigated whether MT1G functionally contributes to all-trans retinoic acid (ATRA)-induced NB4 cell differentiation. Real-time PCR analyses demonstrated that the inductions of CD11b and CD11c and reductions in myeloperoxidase and c-myc by ATRA were significantly attenuated in NB4MTOE cells. Morphological examination revealed that the percentages of differentiated cells induced by ATRA were reduced in NB4MTOE cells. Since G1 arrest is a hallmark of ATRA-induced NB4 cell differentiation, we observed a decrease in G1 accumulation, as well as decreases in p21WAF1/CIP1 and cyclin D1 inductions, by ATRA in NB4MTOE cells. Nitroblue tetrazolium (NBT) reduction assays revealed that the proportions of NBT-positive cells were decreased in NB4MTOE cells in the presence of ATRA. Microarray analyses showed that the changes in expression of several myeloid differentiation-related genes (GATA2, azurocidin 1, pyrroline-5-carboxylate reductase 1, matrix metallopeptidase -8, S100 calcium-binding protein A12, neutrophil cytosolic factor 2 and oncostatin M) induced by ATRA were disturbed in NB4MTOE cells. Collectively, overexpression of MT1G inhibits the proper differentiation of myeloid cells.
authors: Division of Molecular Hematology, Kitasato University Graduate School of Medical Sciences, Minami-ku, Sagamihara, Japan.
authors: Naomi
authors: N
authors: Hirako
authors: Division of Hematology, Kitasato University School of Allied Health Sciences, Minami-ku, Sagamihara, Japan.
authors: Hiroko
authors: H
authors: Nakano
authors: Division of Molecular Hematology, Kitasato University Graduate School of Medical Sciences, Minami-ku, Sagamihara, Japan; Division of Hematology, Kitasato University School of Allied Health Sciences, Minami-ku, Sagamihara, Japan.
authors: Shinichiro
authors: S
authors: Takahashi
mesh_terms: D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects*; D045744:Cell Line, Tumor; D059585:G1 Phase Cell Cycle Checkpoints / Q000187:drug effects / Q000235:genetics; D015870:Gene Expression; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D006801:Humans; D016130:Immunophenotyping; D015473:Leukemia, Promyelocytic, Acute / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D008668:Metallothionein / Q000235:genetics*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D015203:Reproducibility of Results; D015534:Trans-Activators / Q000378:metabolism*; D014212:Tretinoin / Q000494:pharmacology*; D000099232:Proto-Oncogene Protein Spi-1
chemical_list: D015703:Antigens, CD; D008668:Metallothionein; D011518:Proto-Oncogene Proteins; D015534:Trans-Activators; D014212:Tretinoin; D000099232:Proto-Oncogene Protein Spi-1; C499629:MT1G protein, human