NU 9056 is an effective and selective inhibitor of KAT5 histone acetyltransferase with an IC50 of 2 µM. NU 9056 blocks DNA damage response and inhibits protein acetylation in prostate cancer cell lines.

NU 9056 shows IC50s of 60, 36, and >100 μM for KAT5, p300, pCAF and GCN5, respectively. In LNCaP cells, NU 9056 (17 µM, 24 µM, 36 µM) activates both caspase 3 and caspase 9 in a time- and concentration-dependent manner thereby inducing apoptosis. NU 9056 (2.5 µM, 5 µM, 10 µM, 20 µM, 40 µM) decreases the levels of acetylated histone H4K16, H3K14 and H4K8. NU 9056 causes a reduction of androgen receptor, prostate specific antigen, p53 and p21 protein levels[2].

In mice, NU 9056 (2 μg/g) inhibits Tip60 and reduces H2A.Z binding at the the +1 nucleosome of Arc and Syp and the -1 nucleosome of Arc. NU 9056 increases the acetylation at the +1 nucleosome of Gria4 and the -1 nucleosome of Fos, Tacstd2, and Gria4[1].