Trichostatin A (TSA; ) is a potent, reversible inhibitor of histone deacetylase (HDAC) that inhibits HDAC1 (IC50 = 70 nM) in Jurkat cells, resulting in cell cycle arrest. ITSA1 is a cell-permeable benzotriazole amide that blocks TSA action, reducing TSA-induced acetylation of histone and tubulin in A549 cells when given at 50 μM. At the same concentration, ITSA1 also prevents TSA-mediated cell cycle arrest and apoptosis. It similarly blocks the action of the HDAC inhibitor SAHA , preventing SAHA-induced hyperacetylation of tubulin in A549 cells. ITSA1 reduces TSA-regulated transcription in mouse embryonic stem cells and in zebrafish.
