title: Two classes of continuous cell lines established from Syrian hamster 9 day gestation embryos: preneoplastic cells and progenitor cells.
abstract: Primary cultures of 9-d-gestation Syrian hamster embryo (E9) cells are distinct from primary cultures of later gestational age in terms of their growth and differentiation. First, primary E9 cell cultures express multiple mesenchymal differentiation lineages (e.g., adipocyte, myoblast) only rarely seen in cultures of 13-d-gestation fetal (F13) cells. Second, although most primary E9 cultures have a limited in vitro proliferative life span and exhibit cellular senescence similar to primary cultures of F13 cells, E9 cultures seem to have higher frequency of escape from senescence and conversion to continuous cell lines compared to F13 cells. Moreover, this frequency can be further increased 4- to 5-fold by continuous exposure of the E9 cells to tumor promoters or epidermal growth factor. Eleven continuous cell lines have been isolated from untreated, promoter-treated, or epidermal growth factor-treated primary E9 cultures. Seven of these are neoplastic or preneoplastic. However, the remaining four do not show any evidence of being in neoplastic progression and three of these continue to express the same differentiated phenotype observed in ther parental primary cell cultures.
authors.affiliation: Division of Biophysics, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, Maryland 21205.
authors.forename: T
authors.initials: T
authors.lastname: Okeda
authors.forename: Y
authors.initials: Y
authors.lastname: Yokogawa
authors.forename: H
authors.initials: H
authors.lastname: Ueo
authors.forename: M A
authors.initials: MA
authors.lastname: Bury
authors.forename: P O
authors.initials: PO
authors.lastname: Ts'o
authors.forename: S A
authors.initials: SA
authors.lastname: Bruce
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002470:Cell Survival; D006224:Cricetinae; D004622:Embryo, Mammalian; D004815:Epidermal Growth Factor / Q000494:pharmacology; D005865:Gestational Age; D008647:Mesocricetus; D009374:Neoplasms, Experimental / Q000473:pathology*; D010703:Phorbol Esters / Q000494:pharmacology; D011003:Ploidies; D013234:Stem Cells / Q000166:cytology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D010703:Phorbol Esters; C008876:phorbol-12,13-didecanoate; D004815:Epidermal Growth Factor; D013755:Tetradecanoylphorbol Acetate