title: Correlation of c-kit expression and cell cycle regulation by transforming growth factor-beta in CD34+ CD38- human bone marrow cells.
abstract: To investigate the relationship between c-kit expression and cell cycle regulation by endogenous transforming growth factor-beta (TGF-beta) in human bone marrow hematopoietic progenitor cells, CD34+ CD38- c-kit(low/-) and CD34+ CD38- c-kit(high) populations were cultured in stem cell factor, thrombopoietin, interleukin-3 (IL-3), IL-6, granulocyte colony-stimulating factor, granulocyte/macrophage colony-stimulating factor and anti-TGF-beta, and analyzed for cell cycle status. Arrest in G0/G1 was most prominent in the precultured CD34+ CD38- c-kit(low/-) subset (95.62 +/- 4.15%). While postcultured CD34+ CD38- c-kit(high) cells initiated from CD34+ CD38- c-kit(high) cells entered cell cycle within 36 hr, postcultured CD34+ CD38- c-kit(low/-) cells initiated from CD34+ CD38- c-kit(low/-) cells remained dormant until 36 hr and entered cell cycle within 90 hr. Anti-TGF-beta increased the percentage of S/G2M phase postcultured CD34+ CD38- c-kit(high) cells (from 19.08 +/- 11.95 to 47.04 +/- 2.93%), but no significant change was observed in postcultured CD34+ CD38- c-kit(low/-) cells. These results suggest that endogenous TGF-beta plays an important role in the cell cycle arrest of c-kit(high) but not c-kit(low/-) cells in CD34+ CD38- cells, which proliferate without undergoing differentiation. The different regulatory mechanism of cell cycle entry of the CD34+ CD38- c-kit(high) and CD34+ CD38- c-kit(low/-) subsets might be the result of differences in their sensitivity to endogenous TGF-beta.
authors.affiliation: Department of Pediatrics, Hyogo College of Medicine 1-1 Mukogawa-cho, Nishinomiya, Hyogo, Japan. mori-ped@hyo-med.ac.jp
authors.forename: Naoko
authors.initials: N
authors.lastname: Morita
authors.forename: Masuji
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Takakuni
authors.initials: T
authors.lastname: Tanizawa
mesh_terms: D036541:ADP-ribosyl Cyclase / Q000032:analysis; D051997:ADP-ribosyl Cyclase 1; D000328:Adult; D015703:Antigens, CD / Q000032:analysis; D018952:Antigens, CD34 / Q000032:analysis; D001854:Bone Marrow Cells / Q000187:drug effects* / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects*; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured / Q000187:drug effects / Q000378:metabolism; D016895:Culture Media, Serum-Free / Q000494:pharmacology; D016207:Cytokines / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects*; D016298:Hematopoietic Cell Growth Factors / Q000494:pharmacology; D006412:Hematopoietic Stem Cells / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D008562:Membrane Glycoproteins; D019009:Proto-Oncogene Proteins c-kit / Q000096:biosynthesis* / Q000235:genetics; D016212:Transforming Growth Factor beta / Q000037:antagonists & inhibitors / Q000494:pharmacology* / Q000502:physiology
chemical_list: D015703:Antigens, CD; D018952:Antigens, CD34; D016895:Culture Media, Serum-Free; D016207:Cytokines; D016298:Hematopoietic Cell Growth Factors; D008562:Membrane Glycoproteins; D016212:Transforming Growth Factor beta; D019009:Proto-Oncogene Proteins c-kit; D036541:ADP-ribosyl Cyclase; C498154:CD38 protein, human; D051997:ADP-ribosyl Cyclase 1