title: Enrichment of non-synchronized cells in the G1, S and G2 phases of the cell cycle for the study of apoptosis.
abstract: The susceptibility of cells to apoptosis induction is deeply influenced by their position in the cell cycle. Unfortunately, however, current methods for the enrichment of cells in defined phases of the cell cycle are mostly based on the synchronization of cells by agents or conditions that are intrinsically toxic and induce apoptosis on their own. We developed a novel procedure for the purification of cells in distinct phases of the cell cycle. This method is based on the stable transfection of cells with a chimeric protein made up by histone H2B and green fluorescent protein (GFP). Cytofluorometric purification of cells defined by their size and their H2B-GFP-dependent fluorescence (which reflects chromatin and hence DNA content) allowed for the efficient separation of diploid and tetraploid cells in the fluorescence-activated cell sorter (FACS). Moreover, when applied to diploid cells, this method allowed for the enrichment of live, functional cells in the G1, S and G2 phases of the cell cycle. FACS-purified cells were viable and readily resumed the cell cycle upon reculture. While staurosporine was equally toxic for cells in any phase of the cell cycle, camptothecin was particularly toxic for cells in the S phase. Moreover, BAY11-7082, a specific inhibitor of the IKK complex required for NF-kappaB activation, exhibited a particular cell cycle-specific profile of toxicity (G2>S>G1). These results delineate a novel procedure for studying the intersection between cell cycle regulation and cell death mechanisms.
authors.affiliation: Centre National de la Recherche Scientifique, UMR8125, Institut Gustave Roussy, 39 rue Camille-Desmoulins, F-94805 Villejuif, France.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Coquelle
authors.forename: Shahul
authors.initials: S
authors.lastname: Mouhamad
authors.forename: Marie O
authors.initials: MO
authors.lastname: Pequignot
authors.forename: Thorsten
authors.initials: T
authors.lastname: Braun
authors.forename: Gabrielle
authors.initials: G
authors.lastname: Carvalho
authors.forename: Sonia
authors.initials: S
authors.lastname: Vivet
authors.forename: Didier
authors.initials: D
authors.lastname: Métivier
authors.forename: Maria
authors.initials: M
authors.lastname: Castedo
authors.forename: Guido
authors.initials: G
authors.lastname: Kroemer
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D001973:Bromodeoxyuridine / Q000378:metabolism; D002166:Camptothecin / Q000494:pharmacology; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D003110:Colonic Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005434:Flow Cytometry / Q000379:methods*; D005455:Fluorescent Antibody Technique; D006801:Humans; D007399:Interphase / Q000187:drug effects; D009570:Nitriles / Q000494:pharmacology; D011003:Ploidies; D019311:Staurosporine / Q000494:pharmacology; D013450:Sulfones / Q000494:pharmacology
chemical_list: C434003:3-(4-methylphenylsulfonyl)-2-propenenitrile; D004791:Enzyme Inhibitors; D009570:Nitriles; D013450:Sulfones; D001973:Bromodeoxyuridine; D019311:Staurosporine; D002166:Camptothecin