title: Expression of the thymosin beta 4 gene during differentiation of hematopoietic cells.
abstract: Thymosin beta 4 (T beta 4) was originally isolated as a thymic hormone. Its functional properties remain obscure; however, the N-terminal peptidic sequence could have a regulatory function on hematopoietic stem cell proliferation. To investigate the mechanism of T beta 4 expression, we studied T beta 4 gene expression in various leukemic cells and in established cell lines. Among leukemic cell samples obtained from leukemia patients, the T beta 4 gene was highly expressed in a lymphoid lineage, especially in adult T-cell leukemia (ATL) cells, rather than in a granulocyte lineage. The T beta 4 gene was more transcriptionally active in chronic B-cell leukemia than in acute B-cell leukemia, while it was inactive in plasma cell leukemia. We also found that cells from one of the ATL patients transcribed a heterogeneous message. T beta 4 messenger RNA increased in MOLT-3 during differentiation by 12-O-tetradecanoylphorbol-13-acetate (TPA), in HL60 cells induced by TPA or dimethylsulfoxide and K562 cells stimulated by cytosine arabinoside or hemin. The genomic sequence of T beta 4 is considered to be highly conserved. Only 1 of 20 genomes from normal or hematopoietic malignant cells showed restriction fragment length polymorphism. These findings, along with previous data, suggest that T beta 4 may be a new marker of differentiation of hematopoietic cells.
authors.affiliation: First Department of Internal Medicine, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Shimamura
authors.forename: J
authors.initials: J
authors.lastname: Kudo
authors.forename: H
authors.initials: H
authors.lastname: Kondo
authors.forename: K
authors.initials: K
authors.lastname: Dohmen
authors.forename: H
authors.initials: H
authors.lastname: Gondo
authors.forename: S
authors.initials: S
authors.lastname: Okamura
authors.forename: H
authors.initials: H
authors.lastname: Ishibashi
authors.forename: Y
authors.initials: Y
authors.lastname: Niho
mesh_terms: D000328:Adult; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D005260:Female; D005786:Gene Expression Regulation; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D007938:Leukemia / Q000097:blood*; D007962:Leukocytes / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000235:genetics; D012016:Reference Values; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013947:Thymosin / Q000031:analogs & derivatives* / Q000235:genetics; D014158:Transcription, Genetic; D000099201:Thymosin beta(4)
chemical_list: D012333:RNA, Messenger; D013755:Tetradecanoylphorbol Acetate; D013947:Thymosin; D000099201:Thymosin beta(4)