Abstract: |
The PML gene is fused to the retinoic acid receptor α gene (RARα) in the acute promyelocytic leukemia (APL) 15;17 translocation. PML is expressed in diverse tissues and cell lines and localized in the nucleus with a typical speckled pattern. In the bone marrow, it is preferentially expressed in myeloid cells. PML appears to be transcriptionally regulated by class I and II interferons, which raises the possibility that interferons modulate the function and growth and differentiation potential of normal myeloid cells and precursors by activating PML-dependent pathways. Similarly, interferons could act on APL cells, alone or in combination with all-trans retinoic acid (RA), especially if the PML/RARα fusion transcript that results from the t(15;17) is induced by interferon. We report here that PML is expressed at low levels or not expressed in normal circulating human monocytes, lymphocytes, and polymorphonucleate cells, but is markedly induced by interferon; that PML and PML/RARα expression is augmented by interferon in the NB4 APL cell line, which carries the t(15;17), and in APL blasts from patients; that interferon inhibits growth and survival of NB4 APL cells in cooperation with RA; that interferons alone have minimal maturation effect on NB4 cells; and, finally, that interferon γ, but not α or β, induces maturation and growth suppression of NB4 cells with de novo retinoid resistance, and partially restores RA response. |
Keywords: |
human cell; interferon; drug potentiation; cell viability; cell division; cell growth; cell maturation; neoplasm proteins; cell differentiation; drug resistance, neoplasm; tumor cells, cultured; transcription factors; nuclear proteins; leukemia, promyelocytic, acute; transcription regulation; gamma interferon; recombinant gamma interferon; interferon-gamma, recombinant; tumor suppressor proteins; acute myeloblastic leukemia; promyelocytic leukemia; oncogene proteins, fusion; immunoblotting; translocation, genetic; bone marrow cell; beta interferon; retinoic acid; gene expression regulation, leukemic; chromosomes, human, pair 17; chromosomes, human, pair 15; retinoic acid receptor; leukocytes; tretinoin; interferon alfa-2a; tumor stem cells; humans; human; priority journal; article; chromosome translocation 15; recombinant alpha interferon a
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