title: Tumor development is associated with decrease of TET gene expression and 5-methylcytosine hydroxylation.
abstract: The TET (ten-eleven translocation) family of α-ketoglutarate (α-KG)-dependent dioxygenases catalyzes the sequential oxidation of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), 5-formylcytosine and 5-carboxylcytosine, leading to eventual DNA demethylation. The TET2 gene is a bona fide tumor suppressor frequently mutated in leukemia, and TET enzyme activity is inhibited in IDH1/2-mutated tumors by the oncometabolite 2-hydroxyglutarate, an antagonist of α-KG, linking 5mC oxidation to cancer development. We report here that the levels of 5hmC are dramatically reduced in human breast, liver, lung, pancreatic and prostate cancers when compared with the matched surrounding normal tissues. Associated with the 5hmC decrease is the substantial reduction of the expression of all three TET genes, revealing a possible mechanism for the reduced 5hmC in cancer cells. The decrease of 5hmC was also observed during tumor development in different genetically engineered mouse models. Together, our results identify 5hmC as a biomarker whose decrease is broadly and tightly associated with tumor development.
authors.affiliation: Molecular and Cell Biology Lab, Institutes of Biomedical Sciences, Fudan University, Shanghai, PR China.
authors.forename: H
authors.initials: H
authors.lastname: Yang
authors.forename: Y
authors.initials: Y
authors.lastname: Liu
authors.forename: F
authors.initials: F
authors.lastname: Bai
authors.forename: J-Y
authors.initials: JY
authors.lastname: Zhang
authors.forename: S-H
authors.initials: SH
authors.lastname: Ma
authors.forename: J
authors.initials: J
authors.lastname: Liu
authors.forename: Z-D
authors.initials: ZD
authors.lastname: Xu
authors.forename: H-G
authors.initials: HG
authors.lastname: Zhu
authors.forename: Z-Q
authors.initials: ZQ
authors.lastname: Ling
authors.forename: D
authors.initials: D
authors.lastname: Ye
authors.forename: K-L
authors.initials: KL
authors.lastname: Guan
authors.forename: Y
authors.initials: Y
authors.lastname: Xiong
mesh_terms: D044503:5-Methylcytosine / Q000378:metabolism / Q000031:analogs & derivatives; D000818:Animals; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002471:Cell Transformation, Neoplastic / Q000235:genetics*; D003596:Cytosine / Q000031:analogs & derivatives* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics*; D049308:Dioxygenases / Q000235:genetics*; D015536:Down-Regulation; D006801:Humans; D006900:Hydroxylation; D051379:Mice; D006899:Mixed Function Oxygenases; D009369:Neoplasms / Q000235:genetics*; D011518:Proto-Oncogene Proteins / Q000235:genetics*
chemical_list: D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; C011865:5-hydroxymethylcytosine; D044503:5-Methylcytosine; D003596:Cytosine; D006899:Mixed Function Oxygenases; C462539:TET1 protein, human; C578792:TET3 protein, human; D049308:Dioxygenases; C541081:TET2 protein, human