title: Extracellular ubiquitin regulates the growth of human hematopoietic cells.
abstract: We investigated the effects of extracellular ubiquitin on the colony formation of human hematopoietic progenitor cells (CFU-GM, CFU-E and BFU-E) and a granulocyte-colony stimulating factor (G-CSF)-dependent human myeloblastic leukemic cell line, OCI/AML/1a. Ubiquitin exhibited inhibitory effects on CFU-GM, CFU-E, BFU-E and OCI/AML/1a colony formation. Extracellular ubiquitin also inhibited the growth of KT3 (T lymphoblast), K562 (erythroleukemia) and Daudi (Burkitt's lymphoma) cells, stimulated the growth of HL60 (promyelocytic leukemia) and Jurkat (T-ALL) cells and showed no effect on the growth of U937 cells (monocytic leukemia). These results indicate that another, previously unrecognized function of extracellular ubiquitin is to regulate hematopoiesis.
authors.affiliation: Department of Hematology and Oncology, Osaka University Medical School, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Daino
authors.forename: H
authors.initials: H
authors.lastname: Shibayama
authors.forename: T
authors.initials: T
authors.lastname: Machii
authors.forename: T
authors.initials: T
authors.lastname: Kitani
mesh_terms: D002051:Burkitt Lymphoma; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D003114:Colony-Forming Units Assay; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology; D018922:HL-60 Cells; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects; D006801:Humans; D007377:Interleukin-3 / Q000494:pharmacology; D015850:Interleukin-6 / Q000494:pharmacology; D007938:Leukemia; D004915:Leukemia, Erythroblastic, Acute; D011994:Recombinant Proteins / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D014452:Ubiquitins / Q000494:pharmacology*
chemical_list: D007377:Interleukin-3; D015850:Interleukin-6; D011994:Recombinant Proteins; D014452:Ubiquitins; D016179:Granulocyte Colony-Stimulating Factor