title: Rad18 confers hematopoietic progenitor cell DNA damage tolerance independently of the Fanconi Anemia pathway in vivo.
abstract: In cultured cancer cells the E3 ubiquitin ligase Rad18 activates Trans-Lesion Synthesis (TLS) and the Fanconi Anemia (FA) pathway. However, physiological roles of Rad18 in DNA damage tolerance and carcinogenesis are unknown and were investigated here. Primary hematopoietic stem and progenitor cells (HSPC) co-expressed RAD18 and FANCD2 proteins, potentially consistent with a role for Rad18 in FA pathway function during hematopoiesis. However, hematopoietic defects typically associated with fanc-deficiency (decreased HSPC numbers, reduced engraftment potential of HSPC, and Mitomycin C (MMC) -sensitive hematopoiesis), were absent in Rad18(-/-) mice. Moreover, primary Rad18(-/-) mouse embryonic fibroblasts (MEF) retained robust Fancd2 mono-ubiquitination following MMC treatment. Therefore, Rad18 is dispensable for FA pathway activation in untransformed cells and the Rad18 and FA pathways are separable in hematopoietic cells. In contrast with responses to crosslinking agents, Rad18(-/-) HSPC were sensitive to in vivo treatment with the myelosuppressive agent 7,12 Dimethylbenz[a]anthracene (DMBA). Rad18-deficient fibroblasts aberrantly accumulated DNA damage markers after DMBA treatment. Moreover, in vivo DMBA treatment led to increased incidence of B cell malignancy in Rad18(-/-) mice. These results identify novel hematopoietic functions for Rad18 and provide the first demonstration that Rad18 confers DNA damage tolerance and tumor-suppression in a physiological setting.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Medicine, Division of Hematological Malignancies & Cellular Therapy, Duke University, Durham, NC 27710, USA.
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Poe
authors.affiliation: Department of Medicine, Division of Hematological Malignancies & Cellular Therapy, Duke University, Durham, NC 27710, USA.
authors.forename: Lisong
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Genetics, Carolina Center for Genome Sciences, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Fedoriw
authors.affiliation: Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA.
authors.forename: Siddhi
authors.initials: S
authors.lastname: Desai
authors.affiliation: Department of Genetics, Carolina Center for Genome Sciences, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA.
authors.forename: Terry
authors.initials: T
authors.lastname: Magnuson
authors.affiliation: Department of Biostatistics and Bioinformatics, Duke University, Durham, NC 27710, USA.
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Fedoriw
authors.affiliation: Institute of Resource Development and Analysis (IRDA) Kumamoto University, Kumamoto 860-0811, Japan.
authors.forename: Kimi
authors.initials: K
authors.lastname: Araki
authors.affiliation: Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA.
authors.forename: Yanzhe
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Division of Cell Maintenance, Institute of Molecular Embryology and Genetics (IMEG), Kumamoto University, Kumamoto 860-0811, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tateishi
authors.affiliation: Department of Medicine, Division of Hematological Malignancies & Cellular Therapy, Duke University, Durham, NC 27710, USA stefanie.sarantopoulos@duke.edu.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Sarantopoulos
authors.affiliation: Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA cyrus_vaziri@med.unc.edu.
authors.forename: Cyrus
authors.initials: C
authors.lastname: Vaziri
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004249:DNA Damage; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000502:physiology*; D005199:Fanconi Anemia / Q000235:genetics / Q000378:metabolism; D052236:Fanconi Anemia Complementation Group D2 Protein / Q000235:genetics / Q000378:metabolism; D006410:Hematopoiesis; D006412:Hematopoietic Stem Cells / Q000502:physiology*; D006801:Humans; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009153:Mutagens / Q000494:pharmacology
chemical_list: D004268:DNA-Binding Proteins; C499904:Fancd2 protein, mouse; D052236:Fanconi Anemia Complementation Group D2 Protein; D009153:Mutagens; C485953:Rad18 protein, mouse