Marc Labelle

Inhibition of demethylases by GSK-J1/J4

Arising from L. Kruidenier et al. Nature 488, 404–408 (2012); doi:10.1038/nature11262The recent publication of the first highly potent and specific inhibitor GSK-J1/J4 of the H3K27me3/me2-demethylases JMJD3/KDM6B and UTX/KDM6A provides a potential tool compound for this histone demethylase subfamily. This inhibitor was used in tissue culture assays to conclude that the catalytic activities of the KDM6 proteins are required in inflammatory responses; the generation of the inhibitor is intriguing, because it provides a strategy for generating sub-type-specific inhibitors of the 27-member Jumonji family and for the future treatment of various types of disease. Here we show that the inhibitor is not specific for the H3K27me3/me2-demethylase subfamily in vitro and in tissue culture assays. Thus, the inhibitor cannot be used alone for drawing conclusions regarding the specific role of H3K27me3/me2-demethylase activity in biological processes or disease. There is a Reply to this Brief Communications Arising by Kruidenier et al. Nature 514, http://dx.doi.org/10.1038/nature13689 (2014).

Abstract 5161: The development of therapeutic inhibitors of the KDM5 histone demethylases

Histone methyl marks contribute to the regulation of chromatin architecture and of DNA-based processes such as replication, repair and gene transcription. There is increasing evidence for alterations in histone methylation patterns in cancer and other human diseases. Importantly, aberrant methylation can contribute to deregulated gene expression and thereby to excessive proliferation, survival and metastasis of cancer cells. Histone methyl transferases and demethylases establish a dynamic equilibrium of histone modifications, and the expression and activity of several members of these enzyme families are deregulated in human cancer. The jumonji C-domain histone H3K4me3/2 demethylase KDM5B/PLU1/JARID1B as well as its close relative KDM5A/JARID1A are potential oncogenes. Both proteins are overexpressed in human tumors and the gene encoding KDM5B is e.g. amplified in invasive breast cancer cells. Results obtained with RNA interference and targeted deletions in mice have provided additional support for a critical role of KDM5 demethylases in cancer cells. EpiTherapeutics is developing novel cancer drugs targeting the enzymatic activity of histone demethylases. Here we present our recent progress in obtaining selective, potent, and cell-permeable inhibitors of the KDM5 demethylases. Biochemical and cellular activities, pharmacological data, and in vivo antitumor activity will be discussed. Citation Format: Heidi R. Hudlebusch, Bo Heinemann, Jesper M. Nielsen, Daniela Kleine-Kohlbrecher, Camilla Hauge, Thomas Boesen, Marc Labelle, Lars-Ole Gerlach, Peter Staller, Peter Birk. The development of therapeutic inhibitors of the KDM5 histone demethylases. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5161. doi:10.1158/1538-7445.AM2014-5161