Rapid tumor induction in zebrafish by TALEN-mediated somatic inactivation of the retinoblastoma1 tumor suppressor rb1.
Investigating the in vivo role of tumor suppressor genes in cancer is technically challenging due to their essential requirement during early animal development. To address this bottleneck, we generated genetic mosaic adult zebrafish using TALEN genome editing and demonstrate somatic inactivation of the tumor suppressor retinoblastoma1 (rb1) induces tumorigenesis at high frequency. 11-33% of 1-cell stage embryos injected with TALEN mRNAs targeting rb1 exon 2 or 3 develop tumors beginning as early as 3.5 months of age. Lesions predominantly arise in the brain and show features of neuroectodermal-like and glial-like tumors. Mutant allele analysis is consistent with tumor initiation due to somatic inactivation of rb1, revealing a conserved role for rb1 in tumor suppression across vertebrates. In contrast to genetic mosaics, heterozygous rb1-/+ adults show no evidence of neoplasia, while homozygous mutant rb1-/- are larval lethal. This is the first demonstration that somatic inactivation of a tumor suppressor causes cancer in zebrafish, and highlights the utility of site-specific nucleases to create genetic mosaic zebrafish for tumor suppressor gene discovery. Somatic inactivation with site-directed nucleases in zebrafish presents a rapid and scalable strategy to study tumor suppressor gene function in cancer.
Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA.
Staci L
SL
Solin
Department of Population Health and Pathobiology, North Carolina State University, Raleigh, NC 27607, USA.
Heather R
HR
Shive
Department of Pathology, Microbiology and Immunology, University of California Davis, Davis, CA 95616, USA.
Kevin D
KD
Woolard
Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA.
Jeffrey J
JJ
Essner
Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA.
Maura
M
McGrail
D000483:Alleles; D000818:Animals; D001483:Base Sequence; D001932:Brain Neoplasms / Q000235:genetics / Q000473:pathology; D002471:Cell Transformation, Neoplastic / Q000235:genetics*; D004195:Disease Models, Animal; D004720:Endonucleases / Q000378:metabolism*; D005787:Gene Frequency; D020868:Gene Silencing; D018390:Gene Targeting; D056426:Genetic Loci; D005854:Germ Cells / Q000378:metabolism; D006801:Humans; D008940:Mitotic Index; D016160:Retinoblastoma Protein / Q000737:chemistry / Q000235:genetics*; D016415:Sequence Alignment; D015027:Zebrafish
D016160:Retinoblastoma Protein; D004720:Endonucleases