HAT Inhibitor II, a cell-permeable bis-arylidene cyclohexanone compound, selectively inhibits the histone acetyltransferase p300/CREB-binding protein (CBP) with an IC50 value of 5 μM. It affects GCN5 and PCAF acetyltransferases only at much higher concentrations.

Histone acetyltransferase p300, a ubiquitously expressed global transcriptional coactivator, plays critical roles in a wide variety of cellular phenomena, involving in cell cycle control, differentiation, and apoptosis.

In vitro: HAT Inhibitor II dose-dependently suppressed the proliferation of U251, U87, HS683 and SHG44 cells. In HAT Inhibitor II-treated U251 and SHG44 cells, cell cycle arrest at the G2/M phase was triggered by HAT Inhibitor II, significant levels of apoptosis, apoptotic body formation and DNA fragmentation were induced, and cleavage of caspase-3, caspase-9 and PARP were caused. Additionally, HAT Inhibitor II upregulated 965 genes and downregulated 984 genes in HAT inhibitor II-treated U251 cells [1].

In vivo: C57BL/6J mice were intraperitoneally administrated with HAT Inhibitor II at a dose of 185 μg/g for 15 min. In muscle early postmortem, HAT Inhibitor II inhibited protein acetylation, which reduced AMP-activated protein kinase activation induced increase in the total acetylated proteins as well as glycolytic rate [2].

References:
[1].  Xu, L., Li, Z., Tao, Y., Li, R., Fang, F., & Zhao, H. et al. Histone acetyltransferase inhibitor II induces apoptosis in glioma cell lines via the p53 signaling pathway. Journal of Experimental & Clinical Cancer Research. 2014; 33:108.
[2].  Li, Q., Li, Z., Lou, A., Wang, Z., Zhang, D., & Shen, Q. Histone acetyltransferase inhibitors antagonize AMP-activated protein kinase in postmortem glycolysis. Asian-Australasian Journal of Animal Sciences. 2016; 30(6): 857-864.