First-in-Class Selective Inhibitors of the Lysine Acetyltransferase KAT8.

KAT8 is a lysine acetyltransferase primarily catalyzing the acetylation of Lys16 of histone H4 (H4K16). KAT8 dysregulation is linked to the development and metastatization of many cancer types, including non-small cell lung cancer (NSCLC) and acute myeloid leukemia (AML). Few KAT8 inhibitors have been reported so far, none of which displaying selective activity. Based on the KAT3B/KDAC inhibitor C646, we developed a series of N-phenyl-5-pyrazolone derivatives and identified compounds 19 and 34 as low-micromolar KAT8 inhibitors selective over a panel of KATs and KDACs. Western blot, immunofluorescence, and CETSA experiments demonstrated that both inhibitors selectively target KAT8 in cells. Moreover, 19 and 34 exhibited mid-micromolar antiproliferative activity in different cancer cell lines, including NSCLC and AML, without impacting the viability of nontransformed cells. Overall, these compounds are valuable tools for elucidating KAT8 biology, and their simple structures make them promising candidates for future optimization studies.

State-of-the-art therapy for Down syndrome.

In the last decade, an important effort was made in the field of Down syndrome to find new interventions that improve cognition. These therapies have added to the traditional symptomatic treatments and to the drugs for treating Alzheimer disease in the general population repurposed for Down syndrome. Defining next-generation therapeutics will involve biomarker-based therapeutic decision-making, and preventive and multimodal interventions. However, translation of specific findings into effective therapeutic strategies has been disappointingly slow and has failed in many cases at the clinical level, leading to reduced credibility of mouse studies. This is aggravated by a tendency to favour large-magnitude effects and highly significant findings, leading to high expectations but also to a biased view of the complex pathophysiology of Down syndrome. Here, we review some of the most recent and promising strategies for ameliorating the cognitive state of individuals with Down syndrome. We studied the landscape of preclinical and clinical studies and conducted a thorough literature search on PubMed and ClinicalTrials.gov for articles published between June 2012 and August 2022 on therapies for ameliorating cognitive function in individuals with Down syndrome. We critically assess current therapeutic approaches, why therapies fail in clinical trials in Down syndrome, and what could be the path forward. We discuss some intrinsic difficulties for translational research, and the need for a framework that improves the detection of drug efficacy to avoid discarding compounds too early from the companies' pipelines.