title: Cyclin D3 regulates proliferation and apoptosis of leukemic T cell lines.
abstract: Activation of the T cell receptor in leukemic T cell lines or T cell hybridomas causes growth inhibition. A similar growth inhibition is seen when protein kinase C is activated through addition of phorbol myristate acetate. This inhibition is due to an arrest of cell cycle progression in G(1) combined with an induction of apoptosis. Here we have investigated the mechanism by which these stimuli induce inhibition of proliferation in Jurkat and H9 leukemic T cell lines. We show that expression of cyclin D3 is reduced by each of these stimuli, resulting in a concomitant reduction in cyclin D-associated kinase activity. This reduction in cyclin D3-expression is crucial to the observed G(1) arrest, since ectopic expression of cyclin D3 can abrogate the G(1) arrest seen with each of these stimuli. Moreover, ectopic expression of cyclin D3 also prevents the induction of programmed cell death by phorbol myristate acetate and T-cell receptor activation, leading us to conclude that cyclin D3 not only plays a crucial role in progression through the G(1) phase, but is also involved in regulating apoptosis of T cells.
authors.affiliation: Jordan Laboratory for Hemato-oncology, Department of Hematology, University Hospital Utrecht, 3508 GA Utrecht, The Netherlands.
authors.forename: G J
authors.initials: GJ
authors.lastname: Boonen
authors.forename: B A
authors.initials: BA
authors.lastname: van Oirschot
authors.forename: A
authors.initials: A
authors.lastname: van Diepen
authors.forename: W J
authors.initials: WJ
authors.lastname: Mackus
authors.forename: L F
authors.initials: LF
authors.lastname: Verdonck
authors.forename: G
authors.initials: G
authors.lastname: Rijksen
authors.forename: R H
authors.initials: RH
authors.lastname: Medema
mesh_terms: D000911:Antibodies, Monoclonal / Q000494:pharmacology; D017209:Apoptosis; D002455:Cell Division; D056743:Cyclin D3; D016213:Cyclins / Q000378:metabolism*; D015536:Down-Regulation; D018274:Electroporation; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D019169:Jurkat Cells; D007700:Kinetics; D010766:Phosphorylation; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D016160:Retinoblastoma Protein / Q000378:metabolism; D012694:Serine / Q000378:metabolism; D013601:T-Lymphocytes / Q000166:cytology* / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D000911:Antibodies, Monoclonal; C534696:CCND3 protein, human; D056743:Cyclin D3; D016213:Cyclins; D011948:Receptors, Antigen, T-Cell; D016160:Retinoblastoma Protein; D012694:Serine; D013755:Tetradecanoylphorbol Acetate