TY - JOUR
T1 - D-2-hydroxyglutarate Is necessary and sufficient for isocitrate dehydrogenase 1 mutant-induced MIR148A promoter methylation
AU - Li, Tie
AU - Cox, Christopher D.
AU - Ozer, Byram H.
AU - Nguyen, Nhung T.
AU - Nguyen, Huytram N.
AU - Lai, Thomas J.
AU - Li, Sichen
AU - Liu, Fei
AU - Kornblum, Harley I.
AU - Liau, Linda M.
AU - Nghiemphu, Phioanh L.
AU - Cloughesy, Timothy F.
AU - Lai, Albert
N1 - Funding Information:
T.F. Cloughesy is the chief medical officer at Agile Research Foundation and is a consultant/advisory board member for Abbvie, BMS, Boston BioMedical, Celgene, Cortice, GW Pharma, Lilly, Merck, Novocure, Tocagen, VBI Vaccines, and Wellcome Trust. A. Lai reports receiving a commercial research grant from Genentech/Roche, has received speakers bureau honoraria from Abbvie, and is a consultant/advisory board member for Merck. No potential conflicts of interest were disclosed by the other authors.
Publisher Copyright:
© 2018 AACR.
PY - 2018/6/1
Y1 - 2018/6/1
N2 - Mutant isocitrate dehydrogenase (IDH) 1/2 converts a-ketoglutarate (a-KG) to D-2 hydroxyglutarate (D-2-HG), a putative oncometabolite that can inhibit a-KG-dependent enzymes, including ten-eleven translocation methylcytosine dioxygenase (TET) DNA demethylases. We recently established that miRNAs are components of the IDH1 mutant-associated glioma CpG island methylator phenotype (G-CIMP) and specifically identified MIR148A as a tumor-suppressive miRNA within G-CIMP. However, the precise mechanism by which mutant IDH induces hypermethylation of MIR148A and other G-CIMP promoters remains to be elucidated. In this study, we demonstrate that treatment with exogenous D-2-HG induces MIR148A promoter methylation and transcriptional silencing in human embryonic kidney 293T (293T) cells and primary normal human astrocytes. Conversely, we show that the development of MIR148A promoter methylation in mutant IDH1-overexpressing 293T cells is abrogated via treatment with C227, an inhibitor of mutant IDH1 generation of D-2-HG. Using dot blot assays for global assessment of 5-hydroxymethylcytosine (5-hmC), we show that D-2-HG treatment reduces 5-hmC levels, whereas C227 treatment increases 5-hmC levels, strongly suggesting TET inhibition by D-2-HG. Moreover, we show that withdrawal of D-2-HG treatment reverses methylation with an associated increase in MIR148A transcript levels and transient generation of 5-hmC. We also demonstrate that RNA polymerase II binds endogenously to the predicted promoter region of MIR148A, validating the hypothesis that its transcription is driven by an independent promoter. Implications: Establishment of D-2-HG as a necessary and sufficient intermediate by which mutant IDH1 induces CpG island methylation of MIR148A will help with understanding the efficacy of selective mutant IDH1 inhibitors in the clinic. Mol Cancer Res; 16(6); 947-60.
AB - Mutant isocitrate dehydrogenase (IDH) 1/2 converts a-ketoglutarate (a-KG) to D-2 hydroxyglutarate (D-2-HG), a putative oncometabolite that can inhibit a-KG-dependent enzymes, including ten-eleven translocation methylcytosine dioxygenase (TET) DNA demethylases. We recently established that miRNAs are components of the IDH1 mutant-associated glioma CpG island methylator phenotype (G-CIMP) and specifically identified MIR148A as a tumor-suppressive miRNA within G-CIMP. However, the precise mechanism by which mutant IDH induces hypermethylation of MIR148A and other G-CIMP promoters remains to be elucidated. In this study, we demonstrate that treatment with exogenous D-2-HG induces MIR148A promoter methylation and transcriptional silencing in human embryonic kidney 293T (293T) cells and primary normal human astrocytes. Conversely, we show that the development of MIR148A promoter methylation in mutant IDH1-overexpressing 293T cells is abrogated via treatment with C227, an inhibitor of mutant IDH1 generation of D-2-HG. Using dot blot assays for global assessment of 5-hydroxymethylcytosine (5-hmC), we show that D-2-HG treatment reduces 5-hmC levels, whereas C227 treatment increases 5-hmC levels, strongly suggesting TET inhibition by D-2-HG. Moreover, we show that withdrawal of D-2-HG treatment reverses methylation with an associated increase in MIR148A transcript levels and transient generation of 5-hmC. We also demonstrate that RNA polymerase II binds endogenously to the predicted promoter region of MIR148A, validating the hypothesis that its transcription is driven by an independent promoter. Implications: Establishment of D-2-HG as a necessary and sufficient intermediate by which mutant IDH1 induces CpG island methylation of MIR148A will help with understanding the efficacy of selective mutant IDH1 inhibitors in the clinic. Mol Cancer Res; 16(6); 947-60.
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UR - http://www.scopus.com/inward/citedby.url?scp=85048235022&partnerID=8YFLogxK
U2 - 10.1158/1541-7786.MCR-17-0367
DO - 10.1158/1541-7786.MCR-17-0367
M3 - Article
C2 - 29545476
AN - SCOPUS:85048235022
SN - 1541-7786
VL - 16
SP - 947
EP - 960
JO - Molecular Cancer Research
JF - Molecular Cancer Research
IS - 6
ER -