title: Sequential gene targeting to make chimeric tumor models with de novo chromosomal abnormalities.
abstract: The discovery of chromosomal translocations in leukemia/lymphoma and sarcomas presaged a widespread discovery in epithelial tumors. With the advent of new-generation whole-genome sequencing, many consistent chromosomal abnormalities have been described together with putative driver and passenger mutations. The multiple genetic changes required in mouse models to assess the interrelationship of abnormalities and other mutations are severe limitations. Here, we show that sequential gene targeting of embryonic stem cells can be used to yield progenitor cells to generate chimeric offspring carrying all the genetic changes needed for cell-specific cancer. Illustrating the technology, we show that MLL-ENL fusion is sufficient for lethal leukocytosis and proof of genome integrity comes from germline transmission of the sequentially targeted alleles. This accelerated technology leads to a reduction in mouse numbers (contributing significantly to the 3Rs), allows fluorescence tagging of cancer-initiating cells, and provides a flexible platform for interrogating the interaction of chromosomal abnormalities with mutations.
authors.affiliation: Authors' Affiliations: MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford; Leeds Institute of Molecular Medicine, Wellcome Trust Brenner Building, St. James's University Hospital, University of Leeds, Leeds, United Kingdom; and Molecular Cytogenetics Group, Spanish National Cancer Research Center (CNIO), Melchor Fernandez Almagro, Madrid, Spain.
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Chambers
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Tanaka
authors.forename: Tim
authors.initials: T
authors.lastname: Brend
authors.forename: Hanif
authors.initials: H
authors.lastname: Ali
authors.forename: Nicola J
authors.initials: NJ
authors.lastname: Geisler
authors.forename: Leah
authors.initials: L
authors.lastname: Khazin
authors.forename: Juan C
authors.initials: JC
authors.lastname: Cigudosa
authors.forename: T Neil
authors.initials: TN
authors.lastname: Dear
authors.forename: Kenneth
authors.initials: K
authors.lastname: MacLennan
authors.forename: Terence H
authors.initials: TH
authors.lastname: Rabbitts
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002869:Chromosome Aberrations; D053595:Embryonic Stem Cells / Q000378:metabolism; D018390:Gene Targeting / Q000379:methods*; D006801:Humans; D007964:Leukocytosis / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009369:Neoplasms / Q000235:genetics* / Q000378:metabolism; D015514:Oncogene Proteins, Fusion / Q000235:genetics* / Q000378:metabolism; D013234:Stem Cells / Q000378:metabolism; D014178:Translocation, Genetic / Q000235:genetics*
chemical_list: D015514:Oncogene Proteins, Fusion