Isocitrate dehydrogenases (IDHs) are metabolic enzymes that are mutated in several cancers, resulting in overproduction of d-2-hydroxyglutarate (D-2HG). However, the signalling pathways and factors that regulate mutant IDHs or their metabolites remain elusive. Here, we report that in synchronized cells and cells treated with anti-mitotic agents, wild-type and mutant IDH proteins are induced maximally in G2/M. Moreover, mutant IDH1-expressing cells arrested in G2/M harbour high D2HG levels. Genetic or pharmacological perturbation of Forkhead box protein M1 (FOXM1) abrogates the levels of IDH1 mRNA, protein and D2HG in G2/M. Conversely, overexpression of FOXM1 or hyperactive FOXM1 activates the IDH1 promoter and increases the abundance of its protein levels. In summary, our results show that in G2/M, higher D2HG levels are dependent on FOXM1-mediated transcription of IDH1.
