Specificity for Tip60 Acetyltransferase

NU9056 was tested for in vitro activity against a panel of recombinant HAT enzymes, including p300, PCAF and GCN5, to determine whether it shows greater specificity towards Tip60. A number of compounds were found to inhibit the activity of Tip60 at low micromolar concentrations. However, specificity towards Tip60 over other HAT enzymes tested was found to be greatest with compound 7 (NU9056) as shown in Table 1 (16.5-, 29- and .50-fold for selectivity for Tip60 over PCAF, p300 and GCN5, respectively).

Cell lines

LNCaP cells, PC3 cells, LNCaP-CdxR and CWR22rv1 cells

Preparation method

Limited solubility. General tips for obtaining a higher concentration: Please warm the tube at 37℃ for 10 minutes and/or shake it in the ultrasonic bath for a while. Stock solution can be stored below -20℃ for several months.

Reacting condition

2.5, 5, 10, 20, and 40 μM; 24, 48, 72 and 96 h

Applications

In LNCaP cells, NU9056 decreased levels of acetylated histone H4K16, H3K14 and H4K8, targets for Tip60-mediated acetylation. NU9056 inhibited cell growth with GI50 values of 24 μM and 27 μM for LNCaP and PC3 cells, respectively. LNCaP-CdxR and CWR22rv1 cells showed significantly greater sensitivity to NU9056 than the parental LNCaP cell line with GI50 values of 12 μM and 7.5 μM, respectively. The most sensitive cell line CWR22rv1 actually expressed the most Tip60. Treatment with NU9056 (24 μM) for 24h significantly reduced colony forming ability of LNCaP cells. In LNCaP cells, NU9056 also resulted in both caspase 3 and caspase 9 activation in a time- and concentration-dependent way, and induced apoptosis.

Selective KAT5 (Tip60) histone acetyltransferase inhibitor (IC50 values are < 2, 60, 36, and >100 μM for KAT5, p300, pCAF and GCN5, respectively). Inhibits protein acetylation in prostate cancer cell lines and blocks DNA damage response. Decreases proliferation of LNCaP cells; induces apoptosis via caspase activation.