Abexinostat (PCI-24781)

InformationAbexinostat (PCI-24781, CRA-024781) is a novel pan-HDAC inhibitor mostly targetingHDAC1withKiof 7 nM, modest potent to HDACs 2, 3, 6, and 10 and greater than 40-fold selectivity against HDAC8. Phase 1/2.In vitroPCI-24781 exhibits potent antitumor activity against a variety of tumor cell lines with GI50 ranging from 0.15 μM to 3.09 μM. PCI-24781 also has an antiproliferative effect on HUVEC endothelial cells with GI50 of 0.43 μM. PCI-24781 treatment causes dose-dependent accumulation of both acetylated histones and acetylated tubulin in HCT116 or DLD-1 cells, induces expression of p21, and leads to PARP cleavage and accumulation of the γH2AX. Inhibition of HDAC enzymes by PCI-24781 leads to a significant reduction in the transcription of genes specifically associated with HR, including RAD51. Consistent with inhibition of HR, PCI-24781 treatment results in a decreased ability to perform homology directed repair of I-SceI-induced chromosome breaks in transfected CHO cells. PCI-24781 induces S phase depletion, G2 cell cycle arrest, and apoptosis in soft tissue sarcoma (STS) cells. PCI-24781 induces Rad51 transcriptional repression in STS cells potentially mediated via enhanced E2F1 binding to the Rad51 proximal promoter. PCI-24781 induces caspase and reactive oxygen species-dependent apoptosis through NF-κB mechanisms in Hodgkin lymphoma and non-Hodgkin lymphoma cell lines.In vivoAdministration of PCI-24781 at 200 mg/kg once daily every other day (q.o.d.) significantly inhibits the growth of HCT116 and DLD-1 xenografts in mice by 69% and 59%, respectively. Administration of PCI-24781 at 20 mg/kg, 40 mg/kg, 80 mg/kg, or 160 mg/kg once daily for 4 consecutive days followed by 3 days without treatment each week (q.d. × 4 per week) in the HCT116 model causes inhibition of tumor growth by 48%, 57%, 82.2%, or 80.0%, respectively.Cell Datacell lines：Concentrations：Dissolved in DMSO, final concentrations ~10 μMIncubation Time：48, 72, 96, or 120 hoursPowder Purity:≥95%. Specification: 10mM in DMSO Molecular Formula: C21H23N3O5 Molecular Weight: 397.42