title: IDH1/2 Mutants Inhibit TET-Promoted Oxidation of RNA 5mC to 5hmC.
abstract: TETs (TET1/2/3) play critical roles in multi cellular processes through DNA demethylation driven by oxidation of DNA 5mdC to 5hmdC. Interestingly, recent studies indicated that TETs also oxidate RNA 5mC to 5hmC. However, little is known about the distribution of RNA 5hmC and the regulatory mechanism of RNA 5hmC in human. Here, we show that 5hmC is enriched in mRNA, and IDH1/2 mutants inhibit TET-promoted oxidation of RNA 5mC to 5hmC. Since IDH1/2 mutations have been described to block the DNA oxidative activity of TETs, we hypothesized that IDH1/2 mutations might also inhibit the RNA oxidative activity of TETs. To evaluate the role of IDH1/2 mutations in RNA 5hmC, TETs with/without IDH1/2 mutants were overexpressed in human HEK293 cells. Resultant DNA and RNA were digested and analyzed by triple-quadrupole LC mass spectrometer. DNA 5hmdC and RNA 5hmC modifications were quantified with external calibration curves of appropriate standards. It was found that compared with total RNA (5hmC/C: less than 2 X 10-7), mRNA showed much higher 5hmC level (5hmC/C: ∼7 X 10-6). Further study indicated that IDH1/2 mutants showed significant ability to inhibit TET-promoted RNA5hmC. Consistent with this result, overexpression of IDH1/2 mutants also inhibited TET catalytic domain-promoted oxidation of RNA. In this study, we show not only the enrichment of 5hmC in mRNA, but also a regulatory mechanism of RNA 5hmC-IDH1/2 mutations inhibit TET-promoted RNA 5hmC, which suggests an involvement of IDH1/2 mutations in tumorigenesis through the deregulation of RNA biology.
authors.affiliation: Department of Oncology, Second Affiliated Hospital, Institute of Cancer Stem Cell, DaLian Medical University, 9 Western Lvshun South Road, Dalian, Liaoning 116044, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Xu
authors.affiliation: Department of Oncology, Second Affiliated Hospital, Institute of Cancer Stem Cell, DaLian Medical University, 9 Western Lvshun South Road, Dalian, Liaoning 116044, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
authors.affiliation: Department of Oncology, Second Affiliated Hospital, Institute of Cancer Stem Cell, DaLian Medical University, 9 Western Lvshun South Road, Dalian, Liaoning 116044, China.
authors.forename: Lina
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Oncology, Second Affiliated Hospital, Institute of Cancer Stem Cell, DaLian Medical University, 9 Western Lvshun South Road, Dalian, Liaoning 116044, China.
authors.forename: Yuting
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Department of Oncology, Second Affiliated Hospital, Institute of Cancer Stem Cell, DaLian Medical University, 9 Western Lvshun South Road, Dalian, Liaoning 116044, China.
authors.forename: Guangyu
authors.initials: G
authors.lastname: Zhou
authors.affiliation: Department of Oncology, Second Affiliated Hospital, Institute of Cancer Stem Cell, DaLian Medical University, 9 Western Lvshun South Road, Dalian, Liaoning 116044, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Xie
authors.affiliation: Department of Oncology, Second Affiliated Hospital, Institute of Cancer Stem Cell, DaLian Medical University, 9 Western Lvshun South Road, Dalian, Liaoning 116044, China.
authors.forename: Qingkai
authors.identifier: http://orcid.org/0000-0001-6628-5393
authors.initials: Q
authors.lastname: Yang
mesh_terms: D044503:5-Methylcytosine / Q000031:analogs & derivatives* / Q000378:metabolism*; D045744:Cell Line, Tumor; D004247:DNA / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D049308:Dioxygenases / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D057809:HEK293 Cells; D006801:Humans; D007521:Isocitrate Dehydrogenase / Q000235:genetics* / Q000378:metabolism; D006899:Mixed Function Oxygenases / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D010006:Osteoblasts / Q000166:cytology / Q000201:enzymology; D010084:Oxidation-Reduction; D010957:Plasmids / Q000737:chemistry / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000378:metabolism; D012313:RNA / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014162:Transfection
chemical_list: D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; C011865:5-hydroxymethylcytosine; D012313:RNA; D044503:5-Methylcytosine; D004247:DNA; D006899:Mixed Function Oxygenases; C462539:TET1 protein, human; C578792:TET3 protein, human; C538784:IDH2 protein, human; D007521:Isocitrate Dehydrogenase; C543588:IDH1 protein, human; D049308:Dioxygenases; C541081:TET2 protein, human