sar 156497.

Nanatinostat, also known as Tractinostat, CHR-3996 and VRx-3996, is an orally bioavailable, second-generation hydroxamic acid-based inhibitor of histone deacetylase (HDAC) with potential antineoplastic activity. HDAC inhibitor CHR-3996 inhibits HDAC, resulting in an accumulation of highly acetylated histones, the induction of chromatin remodeling, and the selective transcription of tumor suppressor genes; these events may result in the inhibition of tumor cell division and the induction of tumor cell apoptosis. This agent may upregulate HSP70 and downregulate anti-apoptotic Bcl-2 proteins more substantially than some first-generation HDAC inhibitors. HDACs, upregulated in many tumor cell types, are a family of metalloenzymes responsible for the deacetylation of chromatin histone proteins.

SAR156497 is an exquisitely selective Aurora A, B, and C inhibitor with in vitro and in vivo efficacy with IC50 = 0.5 nM (Aurora A); 1 nM (Aurora B incenp); 3 nM (Aurora C incenp) respectively SAR156497 combines high in vitro potency with satisfactory metabolic stability and limited CYP 3A4 and PDE3 inhibition. In vitro, SAR156497 displayed high antiproliferative activity on a large panel of tumor cell lines without correlation with any particular genetic signature or Aurora kinases expression. It induced significant modulation of Aurora A and Aurora B biomarkers (p-Aurora A and pHH3, respectively) and cell polyploidy, as expected from Aurora A B inhibitors.