Effects of the antisense myb expression on hemin- and erythropoietin-induced erythroid differentiation of K562 cells.
In order to elucidate the role of c-myb gene in erythroid differentiation of K562 cell induced by hemin (Hm) and erythropoietin (Epo), we constructed recombinant plasmid that could produce antisense myb RNA after induction with dexamethasone. During treatment with Hm, K562 cells constitutively expressed c-myb mRNA, and 50% of them began to synthesize hemoglobin (Hb). Expression of antisense myb RNA reduced the amount of c-myb mRNA, and the percentage of Hb-synthesizing cells was decreased to 20%. In the presence of Epo, c-myb mRNA declined and 20% of K562 cells synthesized Hb regardless of antisense myb RNA expression. It is suggested that constitutive expression of c-myb mRNA is necessary for Hm-induced differentiation, and that a decrease in the amount of c-myb mRNA induced by antisense myb RNA expression suppresses Hm-induced differentiation. The amount of c-myb mRNA in K562 cells was reduced during the differentiation induced by Epo. Expression of GATA-1 mRNA was almost constant during Hm-induced differentiation, but increased during Epo treatment. It is supposed that the mechanism of Hm-induced differentiation is distinguished from that of Epo-induced differentiation in K562 cells.
First Department of Internal Medicine, Kagawa Medical School, Japan.
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H
Kamano
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T
Tanaka
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H
Ohnishi
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Kubota
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K
Ikeda
J
J
Takahara
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Irino
S
S
Ottalenghi
D000704:Analysis of Variance; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D003907:Dexamethasone / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D015672:Erythroid Precursor Cells / Q000166:cytology / Q000187:drug effects*; D050981:Erythroid-Specific DNA-Binding Factors; D004921:Erythropoietin / Q000494:pharmacology*; D050982:GATA1 Transcription Factor; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D005914:Globins / Q000235:genetics; D006021:Glycophorins / Q000096:biosynthesis; D006427:Hemin / Q000494:pharmacology*; D006454:Hemoglobins / Q000096:biosynthesis; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000473:pathology; D011518:Proto-Oncogene Proteins / Q000235:genetics; D020598:Proto-Oncogene Proteins c-myb; D016372:RNA, Antisense / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis; D014157:Transcription Factors / Q000235:genetics; D014407:Tumor Cells, Cultured
D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D050982:GATA1 Transcription Factor; C494688:GATA1 protein, human; D006021:Glycophorins; D006454:Hemoglobins; D011518:Proto-Oncogene Proteins; D020598:Proto-Oncogene Proteins c-myb; D016372:RNA, Antisense; D012333:RNA, Messenger; D014157:Transcription Factors; D004921:Erythropoietin; D006427:Hemin; D003907:Dexamethasone; D005914:Globins