title: DNA Damage Follows Repair Factor Depletion and Portends Genome Variation in Cancer Cells after Pore Migration.
abstract: Migration through micron-size constrictions has been seen to rupture the nucleus, release nuclear-localized GFP, and cause localized accumulations of ectopic 53BP1-a DNA repair protein. Here, constricted migration of two human cancer cell types and primary mesenchymal stem cells (MSCs) increases DNA breaks throughout the nucleoplasm as assessed by endogenous damage markers and by electrophoretic "comet" measurements. Migration also causes multiple DNA repair proteins to segregate away from DNA, with cytoplasmic mis-localization sustained for many hours as is relevant to delayed repair. Partial knockdown of repair factors that also regulate chromosome copy numbers is seen to increase DNA breaks in U2OS osteosarcoma cells without affecting migration and with nucleoplasmic patterns of damage similar to constricted migration. Such depletion also causes aberrant levels of DNA. Migration-induced nuclear damage is nonetheless reversible for wild-type and sub-cloned U2OS cells, except for lasting genomic differences between stable clones as revealed by DNA arrays and sequencing. Gains and losses of hundreds of megabases in many chromosomes are typical of the changes and heterogeneity in bone cancer. Phenotypic differences that arise from constricted migration of U2OS clones are further illustrated by a clone with a highly elongated and stable MSC-like shape that depends on microtubule assembly downstream of the transcription factor GATA4. Such changes are consistent with reversion to a more stem-like state upstream of cancerous osteoblastic cells. Migration-induced genomic instability can thus associate with heritable changes.
authors.affiliation: Physical Sciences Oncology Center at Penn (PSOC@Penn), 129 Towne Building, University of Pennsylvania, Philadelphia, PA 19104, USA; Molecular and Cell Biophysics Lab, 129 Towne Building, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Jerome
authors.initials: J
authors.lastname: Irianto
authors.affiliation: Physical Sciences Oncology Center at Penn (PSOC@Penn), 129 Towne Building, University of Pennsylvania, Philadelphia, PA 19104, USA; Molecular and Cell Biophysics Lab, 129 Towne Building, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Yuntao
authors.initials: Y
authors.lastname: Xia
authors.affiliation: Physical Sciences Oncology Center at Penn (PSOC@Penn), 129 Towne Building, University of Pennsylvania, Philadelphia, PA 19104, USA; Molecular and Cell Biophysics Lab, 129 Towne Building, University of Pennsylvania, Philadelphia, PA 19104, USA; Graduate Group, Department of Physics and Astronomy, 129 Towne Building, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Charlotte R
authors.initials: CR
authors.lastname: Pfeifer
authors.affiliation: Molecular and Cell Biophysics Lab, 129 Towne Building, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Avathamsa
authors.initials: A
authors.lastname: Athirasala
authors.affiliation: Physical Sciences Oncology Center at Penn (PSOC@Penn), 129 Towne Building, University of Pennsylvania, Philadelphia, PA 19104, USA; Molecular and Cell Biophysics Lab, 129 Towne Building, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Jiazheng
authors.initials: J
authors.lastname: Ji
authors.affiliation: Physical Sciences Oncology Center at Penn (PSOC@Penn), 129 Towne Building, University of Pennsylvania, Philadelphia, PA 19104, USA; Molecular and Cell Biophysics Lab, 129 Towne Building, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Cory
authors.initials: C
authors.lastname: Alvey
authors.affiliation: Physical Sciences Oncology Center at Penn (PSOC@Penn), 129 Towne Building, University of Pennsylvania, Philadelphia, PA 19104, USA; Molecular and Cell Biophysics Lab, 129 Towne Building, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Manu
authors.initials: M
authors.lastname: Tewari
authors.affiliation: Physical Sciences Oncology Center at Penn (PSOC@Penn), 129 Towne Building, University of Pennsylvania, Philadelphia, PA 19104, USA; Graduate Group, Department of Physics and Astronomy, 129 Towne Building, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Rachel R
authors.initials: RR
authors.lastname: Bennett
authors.affiliation: Physical Sciences Oncology Center at Penn (PSOC@Penn), 129 Towne Building, University of Pennsylvania, Philadelphia, PA 19104, USA; Cancer Biology, Abramson Family Cancer Research Institute, Perelman School of Medicine, 129 Towne Building, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Shane M
authors.initials: SM
authors.lastname: Harding
authors.affiliation: Physical Sciences Oncology Center at Penn (PSOC@Penn), 129 Towne Building, University of Pennsylvania, Philadelphia, PA 19104, USA; Graduate Group, Department of Physics and Astronomy, 129 Towne Building, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Andrea J
authors.initials: AJ
authors.lastname: Liu
authors.affiliation: Physical Sciences Oncology Center at Penn (PSOC@Penn), 129 Towne Building, University of Pennsylvania, Philadelphia, PA 19104, USA; Cancer Biology, Abramson Family Cancer Research Institute, Perelman School of Medicine, 129 Towne Building, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Roger A
authors.initials: RA
authors.lastname: Greenberg
authors.affiliation: Physical Sciences Oncology Center at Penn (PSOC@Penn), 129 Towne Building, University of Pennsylvania, Philadelphia, PA 19104, USA; Molecular and Cell Biophysics Lab, 129 Towne Building, University of Pennsylvania, Philadelphia, PA 19104, USA; Graduate Group, Department of Physics and Astronomy, 129 Towne Building, University of Pennsylvania, Philadelphia, PA 19104, USA. Electronic address: discher@seas.upenn.edu.
authors.forename: Dennis E
authors.initials: DE
authors.lastname: Discher
mesh_terms: D001859:Bone Neoplasms / Q000235:genetics* / Q000473:pathology; D002465:Cell Movement; D002467:Cell Nucleus; D004249:DNA Damage; D004260:DNA Repair; D014644:Genetic Variation; D015894:Genome, Human; D042822:Genomic Instability; D006801:Humans; D012516:Osteosarcoma / Q000235:genetics* / Q000473:pathology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D014157:Transcription Factors
keywords: DNA damage; DNA repair; cancer; copy number variation; extracellular matrix; lamina; migration; motility; nuclear envelope; rupture