Photoactivation of Mutant Isocitrate Dehydrogenase 2 Reveals Rapid Cancer-Associated Metabolic and Epigenetic Changes

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• 作者：Olivia S. Walker ; Simon J. Els?sser ; Mohan Mahesh ; Martin Bachman ; Shankar Balasubramanian ; Jason W. Chin
• 刊名：Journal of the American Chemical Society
• 出版年：2016
• 出版时间：January 27, 2016
• 年：2016
• 卷：138
• 期：3
• 页码：718-721
• 全文大小：293K
• ISSN：1520-5126

文摘

Isocitrate dehydrogenase is mutated at a key active site arginine residue (Arg172 in IDH2) in many cancers, leading to the synthesis of the oncometabolite (R)-2-hydroxyglutarate (2HG). To investigate the early events following acquisition of this mutation in mammalian cells we created a photoactivatable version of IDH2(R172K), in which K172 is replaced with a photocaged lysine (PCK), via genetic code expansion. Illumination of cells expressing this mutant protein led to a rapid increase in the levels of 2HG, with 2HG levels reaching those measured in patient tumor samples, within 8 h. 2HG accumulation is closely followed by a global decrease in 5-hydroxymethylcytosine (5-hmC) in DNA, demonstrating that perturbations in epigenetic DNA base modifications are an early consequence of mutant IDH2 in cells. Our results provide a paradigm for rapidly and synchronously uncloaking diverse oncogenic mutations in live cells to reveal the sequence of events through which they may ultimately cause transformation.