title: Germline TP53 mutations result into a constitutive defect of p53 DNA binding and transcriptional response to DNA damage.
abstract: Li-Fraumeni Syndrome (LFS) results from heterozygous germline mutations of TP53, encoding a key transcriptional factor activated in response to DNA damage. We have recently shown, from a large LFS series, that dominant-negative missense mutations are the most clinically severe and, thanks to a new p53 functional assay in lymphocytes, that they alter the p53 transcriptional response to DNA damage more drastically than null mutations. In this study, we first confirmed this observation by performing the p53 functional assay in lymphocytes from 56 TP53 mutation carriers harbouring 35 distinct alterations. Then, to compare the impact of the different types of germline TP53 mutations on DNA binding, we performed chromatin immunoprecipitation-sequencing (ChIP-Seq) in lymphocytes exposed to doxorubicin. ChIP-Seq performed in wild-type TP53 control lymphocytes accurately mapped 1287 p53-binding sites. New p53-binding sites were validated using a functional assay in yeast. ChIP-Seq analysis of LFS lymphocytes carrying TP53 null mutations (p.P152Rfs*18 or complete deletion) or the low penetrant 'Brazilian' p.R337H mutation revealed a moderate decrease of p53-binding sites (949, 580 and 620, respectively) and of ChIP-Seq peak depths. In contrast, analysis of LFS lymphocytes with TP53 dominant-negative missense mutations p.R273H or p.R248W revealed only 310 and 143 p53-binding sites, respectively, and the depths of the corresponding peaks were drastically reduced. Altogether, our results show that TP53 mutation carriers exhibit a constitutive defect of the transcriptional response to DNA damage and that the clinical severity of TP53 dominant-negative missense mutations is explained by a massive and global alteration of p53 DNA binding.
authors.affiliation: Normandie University, UNIROUEN, Inserm U1245 and Rouen University Hospital, Department of Genetics, F 76000, Normandy Centre for Genomic and Personalized Medicine, Rouen, France.
authors.forename: Yasmine
authors.initials: Y
authors.lastname: Zerdoumi
authors.affiliation: Normandie University, UNIROUEN, Inserm U1245 and Rouen University Hospital, Department of Genetics, F 76000, Normandy Centre for Genomic and Personalized Medicine, Rouen, France.
authors.forename: Raphaël
authors.initials: R
authors.lastname: Lanos
authors.affiliation: Normandie University, UNIROUEN, Inserm U1245 and Rouen University Hospital, Department of Genetics, F 76000, Normandy Centre for Genomic and Personalized Medicine, Rouen, France.
authors.forename: Sabine
authors.initials: S
authors.lastname: Raad
authors.affiliation: Normandie University, UNIROUEN, Inserm U1245 and Rouen University Hospital, Department of Genetics, F 76000, Normandy Centre for Genomic and Personalized Medicine, Rouen, France.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Flaman
authors.affiliation: Normandie University, UNIROUEN, Inserm U1245 and Rouen University Hospital, Department of Genetics, F 76000, Normandy Centre for Genomic and Personalized Medicine, Rouen, France.
authors.forename: Gaëlle
authors.initials: G
authors.lastname: Bougeard
authors.affiliation: Normandie University, UNIROUEN, Inserm U1245 and Rouen University Hospital, Department of Genetics, F 76000, Normandy Centre for Genomic and Personalized Medicine, Rouen, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Frebourg
authors.affiliation: Normandie University, UNIROUEN, Inserm U1245 and Rouen University Hospital, Department of Genetics, F 76000, Normandy Centre for Genomic and Personalized Medicine, Rouen, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Tournier
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D047369:Chromatin Immunoprecipitation; D004247:DNA / Q000097:blood / Q000378:metabolism*; D004249:DNA Damage; D005260:Female; D016158:Genes, p53; D020022:Genetic Predisposition to Disease; D018095:Germ-Line Mutation; D006801:Humans; D007223:Infant; D016864:Li-Fraumeni Syndrome / Q000097:blood / Q000235:genetics*; D008214:Lymphocytes / Q000502:physiology; D008297:Male; D008875:Middle Aged; D014158:Transcription, Genetic; D016159:Tumor Suppressor Protein p53 / Q000235:genetics* / Q000378:metabolism*
chemical_list: C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D004247:DNA