title: Cell death associated with abnormal mitosis observed by confocal imaging in live cancer cells.
abstract: Phenanthrene derivatives acting as potent PARP1 inhibitors prevented the bi-focal clustering of supernumerary centrosomes in multi-centrosomal human cancer cells in mitosis. The phenanthridine PJ-34 was the most potent molecule. Declustering of extra-centrosomes causes mitotic failure and cell death in multi-centrosomal cells. Most solid human cancers have high occurrence of extra-centrosomes. The activity of PJ-34 was documented in real-time by confocal imaging of live human breast cancer MDA-MB-231 cells transfected with vectors encoding for fluorescent γ-tubulin, which is highly abundant in the centrosomes and for fluorescent histone H2b present in the chromosomes. Aberrant chromosomes arrangements and de-clustered γ-tubulin foci representing declustered centrosomes were detected in the transfected MDA-MB-231 cells after treatment with PJ-34. Un-clustered extra-centrosomes in the two spindle poles preceded their cell death. These results linked for the first time the recently detected exclusive cytotoxic activity of PJ-34 in human cancer cells with extra-centrosomes de-clustering in mitosis, and mitotic failure leading to cell death. According to previous findings observed by confocal imaging of fixed cells, PJ-34 exclusively eradicated cancer cells with multi-centrosomes without impairing normal cells undergoing mitosis with two centrosomes and bi-focal spindles. This cytotoxic activity of PJ-34 was not shared by other potent PARP1 inhibitors, and was observed in PARP1 deficient MEF harboring extracentrosomes, suggesting its independency of PARP1 inhibition. Live confocal imaging offered a useful tool for identifying new molecules eradicating cells during mitosis.
authors.affiliation: Cancer Research Center, Sheba Medical Center.
authors.forename: Asher
authors.initials: A
authors.lastname: Castiel
authors.forename: Leonid
authors.initials: L
authors.lastname: Visochek
authors.forename: Leonid
authors.initials: L
authors.lastname: Mittelman
authors.forename: Yael
authors.initials: Y
authors.lastname: Zilberstein
authors.forename: Francoise
authors.initials: F
authors.lastname: Dantzer
authors.forename: Shai
authors.initials: S
authors.lastname: Izraeli
authors.forename: Malka
authors.initials: M
authors.lastname: Cohen-Armon
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000188:drug therapy / Q000201:enzymology / Q000473:pathology*; D016923:Cell Death / Q000187:drug effects / Q000502:physiology; D045744:Cell Line, Tumor; D018385:Centrosome / Q000473:pathology; D005260:Female; D006801:Humans; D051379:Mice; D018613:Microscopy, Confocal / Q000379:methods*; D008938:Mitosis / Q000187:drug effects / Q000502:physiology*; D010616:Phenanthrenes / Q000494:pharmacology; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D008941:Spindle Apparatus / Q000473:pathology
chemical_list: C434926:N-(oxo-5,6-dihydrophenanthridin-2-yl)-N,N-dimethylacetamide hydrochloride; D010616:Phenanthrenes; D000067856:Poly(ADP-ribose) Polymerase Inhibitors