IDENTIFICATION OF NEW KDM4 INHIBITORS THROUGH A HTS AND HIT REFINEMENT STRATEGY

JHDMs (JmjC-domain-containing histone demethylases) are the largest class of demethylase enzymes,contain a Jumonji C (JmjC) domain and catalyze lysine demethylation of histones through an oxidative reaction that requires Fe(II) ion and α-ketoglutarate (αkG) as cofactors. The misregulation of these enzymes, in particular JMJD2 subfamily, has being significantly implicated in cancer initiation and progression. Potent and specific inhibitors of these enzymes have not been identified yet, most of them inhibiting many other Fe(II)/ αkG dependent oxygenases or being non specific for the different isoforms.After a preliminary high throughput screening (HTS), we have identified a pool of interesting hits. Then, to refine the results, we performed a hit validation stage, filtering out poor quality scaffolds, not suitable for future optimization. This combined approach led us to select EML586 as a scaffold for further derivatization. From a series of EML586 analogues we were able to derive a pharmacophore hypothesis and structure-activity relationships and selected 3-hydroxy-2,3-dihydroquinazolinone moiety as a starting point for the development of novel optimized derivatives. All the compounds were tested through a peptide-based AlphaLISA assay, measuring the levels of H3K9 dimethylation.