title: Cell cycle differences in vitro between primitive hematopoietic cell populations from adult and umbilical cord blood.
abstract: Lineage-negative (Lin(-)) cell populations, obtained by negative selection from umbilical cord blood (UCB) and adult mobilized peripheral blood (aMPB), were cultured in serum-free liquid cultures supplemented with a mixture of seven stimulatory cytokines. On specific days, proliferation potential was assessed and cell cycle status was determined by DNA content. Expression of the cell cycle regulators cyclin D3 (cD3), cyclin-dependent kinase 4 (cdk4), p21(cip1/waf1) (p21), and p27(kip1) (p27) was also determined. As expected, UCB cells showed significantly higher proliferation potentials than aMPB cells, particularly during the first 7 days of culture. During this period of time, higher numbers of cell cycles were observed in UCB cells (7-9 cycles), as compared to aMPB cells (5-6 cycles). Higher levels of cD3, cdk4, and p27 were also detected in UCB cells. Our results confirm that UCB cells possess an intrinsically higher proliferation potential, as compared to aMPB cells, and suggest that such a biological difference is due, at least in part, to differences in cell cycle status. This, in turn, seems to result from the differential expression of cell cycle regulatory molecules.
authors.affiliation: Oncology Research Unit, Oncology Hospital, National Medical Center, IMSS, Mexico City, Mexico.
authors.forename: Antonio
authors.initials: A
authors.lastname: Alvarado-Moreno
authors.forename: Antonieta
authors.initials: A
authors.lastname: Chávez-González
authors.forename: Arturo
authors.initials: A
authors.lastname: Cérbulo
authors.forename: Lourdes
authors.initials: L
authors.lastname: Arriaga
authors.forename: Hector
authors.initials: H
authors.lastname: Mayani
mesh_terms: D000293:Adolescent; D000328:Adult; D002453:Cell Cycle / Q000502:physiology*; D018797:Cell Cycle Proteins / Q000378:metabolism; D049109:Cell Proliferation; D005312:Fetal Blood / Q000166:cytology*; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000502:physiology*; D006801:Humans
chemical_list: D018797:Cell Cycle Proteins