C646 is an inhibitor of the histone acetyltransferase p300 (IC50 = 1.6 μM). It competitively (versus acetyl-CoA) binds p300 (Ki = 400 nM) and does not inhibit several other acetyltransferases. The action of C646 appears to be irreversible through covalent modification of the enzyme target. It blocks the growth of human melanoma, leukemia, lung, and prostate cancer cells in vitro. C646 has been used to study the role of p300-mediated acetylation in such models as fear extinction memory and the regulation of immediate-early genes.
Reversible cell permeable p300/CBP histone acetyltransferase (HAT) inhibitor. Specific inhibition to p300 (86%) compared to N-acetyltransferase, PCAF, GCN5, Rtt109, Sas or MOZ histone acetyltransferases (<10%). Cell growth inhibitor in melanoma and non-small-cell-lung (NSCL) human cancer cell lines.
C646 is a pyrazolone that is 5-methyl-4-methylene-2-(p-carboxyphenyl)-2,4-dihydro-3H-pyrazol-3-one in which the exocyclic carbon of the methylene group is attached to a 5-(4,5-dimethyl-2-nitrophenyl)furan-2-yl group by a single bond. C646 is a potent, cell permeable and selective competitive inhibitor of p300 and CBP (p300/CBP) histone acetyltransferases. It has a role as an EC 2.3.1.48 (histone acetyltransferase) inhibitor, an apoptosis inducer and a radiosensitizing agent. It is a member of furans, a biaryl, a pyrazolone, a member of benzoic acids and a C-nitro compound.