title: TALEN-mediated somatic mutagenesis in murine models of cancer.
abstract: Cancer genome sequencing has identified numerous somatic mutations whose biologic relevance is uncertain. In this study, we used genome-editing tools to create and analyze targeted somatic mutations in murine models of liver cancer. Transcription activator-like effector nucleases (TALEN) were designed against β-catenin (Ctnnb1) and adenomatous polyposis coli (Apc), two commonly mutated genes in hepatocellular carcinoma (HCC), to generate isogenic HCC cell lines. Both mutant cell lines exhibited evidence of Wnt pathway dysregulation. We asked whether these TALENs could create targeted somatic mutations after hydrodynamic transfection into mouse liver. TALENs targeting β-catenin promoted endogenous HCC carrying the intended gain-of-function mutations. However, TALENs targeting Apc were not as efficient in inducing in vivo homozygous loss-of-function mutations. We hypothesized that hepatocyte polyploidy might be protective against TALEN-induced loss of heterozygosity, and indeed Apc gene editing was less efficient in tetraploid than in diploid hepatocytes. To increase efficiency, we administered adenoviral Apc TALENs and found that we could achieve a higher mutagenesis rate in vivo. Our results demonstrate that genome-editing tools can enable the in vivo study of cancer genes and faithfully recapitulate the mosaic nature of mutagenesis in mouse cancer models. Cancer Res; 74(18); 5311-21. ©2014 AACR.
authors: Department of Pediatrics, Children's Research Institute, University of Texas Southwestern Medical Center, Dallas, Texas. Department of Internal Medicine, Children's Research Institute, University of Texas Southwestern Medical Center, Dallas, Texas.
authors: Shuyuan
authors: S
authors: Zhang
authors: Department of Pediatrics, Children's Research Institute, University of Texas Southwestern Medical Center, Dallas, Texas. Department of Internal Medicine, Children's Research Institute, University of Texas Southwestern Medical Center, Dallas, Texas.
authors: Lin
authors: L
authors: Li
authors: Department of Pediatrics, Children's Research Institute, University of Texas Southwestern Medical Center, Dallas, Texas. Department of Internal Medicine, Children's Research Institute, University of Texas Southwestern Medical Center, Dallas, Texas.
authors: Sara L
authors: SL
authors: Kendrick
authors: Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas.
authors: Robert D
authors: RD
authors: Gerard
authors: Department of Pediatrics, Children's Research Institute, University of Texas Southwestern Medical Center, Dallas, Texas. Department of Internal Medicine, Children's Research Institute, University of Texas Southwestern Medical Center, Dallas, Texas. Hao.Zhu@utsouthwestern.edu.
authors: Hao
authors: H
authors: Zhu
mesh_terms: D000818:Animals; D004720:Endonucleases / Q000235:genetics*; D005818:Genetic Engineering / Q000379:methods*; D016678:Genome; D064593:Heterografts; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008819:Mice, Nude; D016296:Mutagenesis; D009374:Neoplasms, Experimental / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics*; D015533:Transcriptional Activation; D014162:Transfection
chemical_list: D014157:Transcription Factors; D004720:Endonucleases