TET2-mediated 5-hydroxymethylcytosine induces genetic instability and mutagenesis.
The family of Ten-Eleven Translocation (TET) proteins is implicated in the process of active DNA demethylation and thus in epigenetic regulation. TET 1, 2 and 3 proteins are oxygenases that can hydroxylate 5-methylcytosine (5-mC) into 5-hydroxymethylcytosine (5-hmC) and further oxidize 5-hmC into 5-formylcytosine (5-fC) and 5-carboxylcytosine (5-caC). The base excision repair (BER) pathway removes the resulting 5-fC and 5-caC bases paired with a guanine and replaces them with regular cytosine. The question arises whether active modification of 5-mC residues and their subsequent elimination could affect the genomic DNA stability. Here, we generated two inducible cell lines (Ba/F3-EPOR, and UT7) overexpressing wild-type or catalytically inactive human TET2 proteins. Wild-type TET2 induction resulted in an increased level of 5-hmC and a cell cycle defect in S phase associated with higher level of phosphorylated P53, chromosomal and centrosomal abnormalities. Furthermore, in a thymine-DNA glycosylase (Tdg) deficient context, the TET2-mediated increase of 5-hmC induces mutagenesis characterized by GC>AT transitions in CpG context suggesting a mutagenic potential of 5-hmC metabolites. Altogether, these data suggest that TET2 activity and the levels of 5-hmC and its derivatives should be tightly controlled to avoid genetic and chromosomal instabilities. Moreover, TET2-mediated active demethylation might be a very dangerous process if used to entirely demethylate the genome and might rather be used only at specific loci.
INSERM, UMR 1170, Laboratory of Excellence GR-Ex, Villejuif, France; Université Paris XI, UMR 1170, Gustave Roussy, Villejuif, France; Gustave Roussy, Villejuif, France; Laboratory of Excellence GR-Ex, Villejuif, France; Laboratoire d'hématologie moléculaire et cellulaire, Institut Pasteur de Tunis, Université de Tunis El Manar, Belvédère, Tunisia.
Emna
E
Mahfoudhi
Université Paris XI, UMR 1170, Gustave Roussy, Villejuif, France; Gustave Roussy, Villejuif, France; CNRS UMR8200, Groupe "Réparation de l'ADN", Université Paris-Sud, Gustave Roussy Cancer Campus, F-94805 Villejuif Cedex, France.
Ibtissam
I
Talhaoui
INSERM, UMR 1170, Laboratory of Excellence GR-Ex, Villejuif, France; Université Paris XI, UMR 1170, Gustave Roussy, Villejuif, France; Gustave Roussy, Villejuif, France; Laboratory of Excellence GR-Ex, Villejuif, France.
Xenia
X
Cabagnols
INSERM, UMR 1170, Laboratory of Excellence GR-Ex, Villejuif, France; Université Paris XI, UMR 1170, Gustave Roussy, Villejuif, France; Gustave Roussy, Villejuif, France; Laboratory of Excellence GR-Ex, Villejuif, France.
Véronique
V
Della Valle
INSERM, UMR 1170, Laboratory of Excellence GR-Ex, Villejuif, France; Université Paris XI, UMR 1170, Gustave Roussy, Villejuif, France; Gustave Roussy, Villejuif, France; Laboratory of Excellence GR-Ex, Villejuif, France.
Lise
L
Secardin
Laboratory of Excellence GR-Ex, Villejuif, France; Gustave Roussy, Flow Cytometry Platform, Villejuif, France.
Philippe
P
Rameau
INSERM, UMR 1170, Laboratory of Excellence GR-Ex, Villejuif, France; Université Paris XI, UMR 1170, Gustave Roussy, Villejuif, France; Gustave Roussy, Villejuif, France; Laboratory of Excellence GR-Ex, Villejuif, France.
Olivier A
OA
Bernard
Université Paris XI, UMR 1170, Gustave Roussy, Villejuif, France; Gustave Roussy, Villejuif, France; CNRS UMR8200, Groupe "Réparation de l'ADN", Université Paris-Sud, Gustave Roussy Cancer Campus, F-94805 Villejuif Cedex, France.
Alexander A
AA
Ishchenko
Laboratoire d'hématologie moléculaire et cellulaire, Institut Pasteur de Tunis, Université de Tunis El Manar, Belvédère, Tunisia.
Salem
S
Abbes
INSERM, UMR 1170, Laboratory of Excellence GR-Ex, Villejuif, France; Université Paris XI, UMR 1170, Gustave Roussy, Villejuif, France; Gustave Roussy, Villejuif, France; Laboratory of Excellence GR-Ex, Villejuif, France.
William
W
Vainchenker
Université Paris XI, UMR 1170, Gustave Roussy, Villejuif, France; Gustave Roussy, Villejuif, France; CNRS UMR8200, Groupe "Réparation de l'ADN", Université Paris-Sud, Gustave Roussy Cancer Campus, F-94805 Villejuif Cedex, France.
Murat
M
Saparbaev
INSERM, UMR 1170, Laboratory of Excellence GR-Ex, Villejuif, France; Université Paris XI, UMR 1170, Gustave Roussy, Villejuif, France; Gustave Roussy, Villejuif, France; Laboratory of Excellence GR-Ex, Villejuif, France. Electronic address: isabelle.plo@gustaveroussy.fr.
Isabelle
I
Plo
D044503:5-Methylcytosine / Q000031:analogs & derivatives* / Q000378:metabolism*; D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000378:metabolism; D001483:Base Sequence; D002460:Cell Line; D003596:Cytosine / Q000031:analogs & derivatives / Q000378:metabolism; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D049308:Dioxygenases; D044127:Epigenesis, Genetic; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D042822:Genomic Instability; D006801:Humans; D006900:Hydroxylation; D055016:Megakaryocyte Progenitor Cells / Q000166:cytology / Q000378:metabolism; D051379:Mice; D016296:Mutagenesis; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000378:metabolism; D016196:S Phase; D044502:Thymine DNA Glycosylase / Q000172:deficiency / Q000235:genetics; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism
C560974:5-carboxylcytosine; C560973:5-formylcytosine; D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; D016159:Tumor Suppressor Protein p53; C011865:5-hydroxymethylcytosine; D044503:5-Methylcytosine; D003596:Cytosine; D049308:Dioxygenases; C541081:TET2 protein, human; D044502:Thymine DNA Glycosylase
5-hmC; Cell cycle; Genetic instability; TDG; TET2