title: Iron deprivation blocks multilineage haematopoietic differentiation by inhibiting induction of p21(WAF1/CIP1).
abstract: Iron is required for the differentiation of HL-60 cells along the monocyte lineage in vitro, reflecting a requirement for iron in the transcriptional induction of the p21(WAF1/CIP1) gene. To determine if the same requirement holds true for differentiation in other cell lineages and for primary human CD34(+) bone marrow precursor cells, we induced granulocyte differentiation by treating HL-60 cells with dimethyl sulphoxide, and erythroid or megakaryocytic differentiation by treating K562 cells with butyrate or phorbol myristate acetate, respectively. Nitro blue tetrazolium reduction, expression of haem, or expression of CD41 was used to assess granulocytic, erythroid, or megakaryocytic differentiation respectively. Purified CD34(+) cells were cultured with granulocyte/macrophage-colony stimulating factor and stem cell factor to induce myelomonocytic differentiation. Iron deprivation was induced by desferrioxamine. p21(WAF1/CIP1) antisense oligonucleotides were used to inhibit p21 expression. Iron deprivation blocked p21 induction as judged by real-time polymerase chain reaction assays. In addition, both iron deprivation and p21 antisense blocked CD34(+) cell differentiation. These observations were not explained by induction of widespread apoptosis under conditions of iron deprivation. We concluded that both iron and functional p21(WAF1/CIP1) are required for in vitro differentiation of human haematopoietic precursors along multiple cell lineages.
authors.affiliation: Medicine/Hematology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA.
authors.forename: Orlando
authors.initials: O
authors.lastname: Alcantara
authors.forename: David H
authors.initials: DH
authors.lastname: Boldt
mesh_terms: D018952:Antigens, CD34 / Q000235:genetics; D016375:Antisense Elements (Genetics) / Q000235:genetics; D017209:Apoptosis / Q000502:physiology; D002087:Butyrates / Q000494:pharmacology; D002273:Carcinogens / Q000494:pharmacology; D002452:Cell Count; D002454:Cell Differentiation / Q000187:drug effects; D045744:Cell Line, Tumor / Q000187:drug effects / Q000502:physiology*; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics*; D003676:Deferoxamine / Q000494:pharmacology; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D015973:Gene Expression Regulation, Leukemic / Q000235:genetics; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D018922:HL-60 Cells / Q000187:drug effects / Q000502:physiology; D006410:Hematopoiesis / Q000187:drug effects / Q000235:genetics*; D006801:Humans; D007501:Iron / Q000378:metabolism*; D020014:K562 Cells / Q000187:drug effects / Q000502:physiology; D017262:Siderophores / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014158:Transcription, Genetic / Q000235:genetics
chemical_list: D018952:Antigens, CD34; D016375:Antisense Elements (Genetics); D002087:Butyrates; C493956:CDKN1A protein, human; D002273:Carcinogens; D050759:Cyclin-Dependent Kinase Inhibitor p21; D017262:Siderophores; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D007501:Iron; D003676:Deferoxamine; D013755:Tetradecanoylphorbol Acetate; D004121:Dimethyl Sulfoxide