An expansion phase precedes terminal erythroid differentiation of hematopoietic progenitor cells from cord blood in vitro and is associated with up-regulation of cyclin E and cyclin-dependent kinase 2.
The dynamics of cell cycle regulation were investigated during in vitro erythroid proliferation and differentiation of CD34(+) cord blood cells. An unusual cell cycle profile with a majority of cells in S phase (70.2%) and minority of cells in G1 phase (27.4%) was observed in burst-forming unit-erythrocytes (BFU-E)-derived erythroblasts from a 7-day culture of CD34(+) cells stimulated with interleukin 3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF), Steel factor, and Epo. Terminal erythroid differentiation was accompanied by a rapid increase of G0/G1 phase cells. Expression of cyclin E and cyclin-dependent kinase 2 (cdk2) correlated with the proportion of S phase cells. Cyclin D3 was moderately up-regulated during the proliferation phase, and both cyclin E and D3 were rapidly down-regulated during terminal differentiation. This suggests that the high proliferation potential of erythroblasts is associated with temporal up-regulation of cyclin E and cdk2. (Blood. 2000;96:3985-3987)
Dai
M S
MS
Department of Microbiology/Immunology, Indiana University School of Medicine, Indianapolis 46202-5121, USA.
Mantel
C R
CR
Xia
Z B
ZB
Broxmeyer
H E
HE
Lu
L
L
D042846:CDC2-CDC28 Kinases; D018929:Cell Culture Techniques; D002453:Cell Cycle / Q000187:drug effects / Q000502:physiology; D018797:Cell Cycle Proteins / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D002454:Cell Differentiation / Q000187:drug effects; D051357:Cyclin-Dependent Kinase 2; D018844:Cyclin-Dependent Kinases / Q000378:metabolism / Q000502:physiology; D016213:Cyclins / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D016207:Cytokines / Q000494:pharmacology; D015672:Erythroid Precursor Cells / Q000166:cytology; D005312:Fetal Blood / Q000166:cytology; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects; D006801:Humans; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism / Q000502:physiology; D015854:Up-Regulation / Q000187:drug effects
D018797:Cell Cycle Proteins; D016213:Cyclins; D016207:Cytokines; D017346:Protein Serine-Threonine Kinases; D042846:CDC2-CDC28 Kinases; C495894:CDK2 protein, human; D051357:Cyclin-Dependent Kinase 2; D018844:Cyclin-Dependent Kinases