title: The N-terminal half of NPM dissociates from nucleoli of HeLa cells after anticancer drug treatments.
abstract: NPM (nucleophosmin/B23) is a nucleolar phosphoprotein abundant in tumor cells. It dissociates from nucleoli of cells after treatments with various anticancer drugs. To determine the domain of NPM responsible for nucleolar binding, the N- and C-terminal halves of NPM were fused to GFP (green fluorescent protein) and introduced into HeLa cells. The N-terminal half (aa 1-150) of NPM (GFP-NPM(N)) was found localized in the nucleoli. A stable transformant of GFP-NPM(N) in HeLa cells was prepared and tested for association to nucleoli after anticancer drug treatments. GFP-NPM(N) dissociates from nucleoli after treatments with daunomycin, actinomycin D, camptothecin, and toyocamycin. The dissociation is time- and dose-dependent, and correlates with the cytotoxicity induced by the drugs. These results indicate that a stable transformant of GFP-NPM(N) in HeLa cells may be useful for the screening of anticancer drugs.
authors.affiliation: Department of Pharmacology, Baylor College of Medicine, Houston, Texas, 77030, USA. pchan@bcm.tmc.edu
authors.forename: P K
authors.initials: PK
authors.lastname: Chan
authors.forename: D A
authors.initials: DA
authors.lastname: Bloom
authors.forename: T T
authors.initials: TT
authors.lastname: Hoang
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D001692:Biological Transport; D002466:Cell Nucleolus / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D004354:Drug Screening Assays, Antitumor; D049452:Green Fluorescent Proteins; D006367:HeLa Cells; D006801:Humans; D008164:Luminescent Proteins / Q000378:metabolism; D009687:Nuclear Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D000090243:Nucleophosmin
chemical_list: D000970:Antineoplastic Agents; D008164:Luminescent Proteins; C000716967:NPM1 protein, human; D009687:Nuclear Proteins; D000090243:Nucleophosmin; D049452:Green Fluorescent Proteins