title: A novel canine kidney cell line model for the evaluation of neoplastic development: karyotype evolution associated with spontaneous immortalization and tumorigenicity.
abstract: The molecular mechanisms underlying spontaneous neoplastic transformation in cultured mammalian cells remain poorly understood, confounding recognition of parallels with the biology of naturally occurring cancer. The broad use of tumorigenic canine cell lines as research tools, coupled with the accumulation of cytogenomic data from naturally occurring canine cancers, makes the domestic dog an ideal system in which to investigate these relationships. We developed a canine kidney cell line, CKB1-3T7, which allows prospective examination of the onset of spontaneous immortalization and tumorigenicity. We documented the accumulation of cytogenomic aberrations in CKB1-3T7 over 24 months in continuous culture. The majority of aberrations emerged in parallel with key phenotypic changes in cell morphology, growth kinetics, and tumor incidence and latency. Focal deletion of CDKN2A/B emerged first, preceding the onset and progression of tumorigenic potential, and progressed to a homozygous deletion across the cell population during extended culture. Interestingly, CKB1-3T7 demonstrated a tumorigenic phenotype in vivo prior to exhibiting loss of contact inhibition in vitro. We also performed the first genome-wide characterization of the canine tumorigenic cell line MDCK, which also exhibited CDKN2A/B deletion. MDCK and CKB1-3T7 cells shared several additional aberrations that we have reported previously as being highly recurrent in spontaneous canine cancers, many of which, as with CDKN2A/B deletion, are evolutionarily conserved in their human counterparts. The conservation of these molecular events across multiple species, in vitro and in vivo, despite their contrasting karyotypic architecture, is a powerful indicator of a common mechanism underlying emerging neoplastic activity. Through integrated cytogenomic and phenotypic characterization of serial passages of CKB1-3T7 from initiation to development of a tumorigenic phenotype, we present a robust and readily accessible model (to be made available through the American Type Culture Collection) of spontaneous neoplastic transformation that overcomes many of the limitations of earlier studies.
authors.affiliation: Laboratory of DNA Viruses, Division of Viral Products, Office of Vaccines Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, 10903 New Hampshire Ave, Silver Spring, MD, 20993, USA.
authors.forename: R
authors.initials: R
authors.lastname: Omeir
authors.affiliation: Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, 1060 William Moore Drive, Raleigh, NC, 27607, USA.|Center for Comparative Medicine and Translational Research, North Carolina State University, Raleigh, NC, 27607, USA.
authors.forename: R
authors.initials: R
authors.lastname: Thomas
authors.affiliation: Laboratory of DNA Viruses, Division of Viral Products, Office of Vaccines Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, 10903 New Hampshire Ave, Silver Spring, MD, 20993, USA.
authors.forename: B
authors.initials: B
authors.lastname: Teferedegne
authors.affiliation: Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, 1060 William Moore Drive, Raleigh, NC, 27607, USA.
authors.forename: C
authors.initials: C
authors.lastname: Williams
authors.affiliation: Laboratory of DNA Viruses, Division of Viral Products, Office of Vaccines Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, 10903 New Hampshire Ave, Silver Spring, MD, 20993, USA.
authors.forename: G
authors.initials: G
authors.lastname: Foseh
authors.affiliation: Laboratory of DNA Viruses, Division of Viral Products, Office of Vaccines Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, 10903 New Hampshire Ave, Silver Spring, MD, 20993, USA.
authors.forename: J
authors.initials: J
authors.lastname: Macauley
authors.affiliation: Division of Veterinary Resources, National Institutes of Health, Bethesda, MD, 20892, USA.
authors.forename: L
authors.initials: L
authors.lastname: Brinster
authors.affiliation: Office of Counter-Terrorism and Emergency Coordination, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, MD, 20993, USA.
authors.forename: J
authors.initials: J
authors.lastname: Beren
authors.affiliation: Laboratory of DNA Viruses, Division of Viral Products, Office of Vaccines Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, 10903 New Hampshire Ave, Silver Spring, MD, 20993, USA.
authors.forename: K
authors.initials: K
authors.lastname: Peden
authors.affiliation: Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, 1060 William Moore Drive, Raleigh, NC, 27607, USA. matthew_breen@ncsu.edu.|Center for Comparative Medicine and Translational Research, North Carolina State University, Raleigh, NC, 27607, USA. matthew_breen@ncsu.edu.|Cancer Genetics Program, University of North Carolina Lineberger Comprehensive Cancer Center, Chapel Hill, NC, 27599, USA. matthew_breen@ncsu.edu.|Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, 27607, USA. matthew_breen@ncsu.edu.
authors.forename: M
authors.initials: M
authors.lastname: Breen
authors.affiliation: Laboratory of DNA Viruses, Division of Viral Products, Office of Vaccines Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, 10903 New Hampshire Ave, Silver Spring, MD, 20993, USA. andrew.lewis@fda.hhs.gov.
authors.forename: A M
authors.initials: AM
authors.lastname: Lewis
mesh_terms: D000818:Animals; D002460:Cell Line; D002461:Cell Line, Transformed; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic / Q000235:genetics*; D002478:Cells, Cultured; D002869:Chromosome Aberrations; D056915:DNA Copy Number Variations; D004285:Dogs; D017404:In Situ Hybridization, Fluorescence; D059785:Karyotype; D061985:Madin Darby Canine Kidney Cells; D008297:Male; D009369:Neoplasms / Q000235:genetics* / Q000473:pathology
keywords: CKB1-3T7 cell line; Canine chromosomes; Comparative genomic hybridization (CGH); Fluorescence in situ hybridization (FISH); Madin-Darby canine kidney (MDCK) cell line; Neoplastic transformation; Tumorigenicity