4SC-202 is a selective, potent and orally available inhibitor of histone deacetylases (HDAC) specific for class I HDAC isoenzymes with an IC50 value of about 1μM [1].

4SC-202 has been reported to selectively inhibit the recombinant class I HDAC isoenzymes with IC50 values of 1.2μM, 1.12μM and 0.57μM for HDAC-1, HDAC-2 and HDAC-3, respectively. In vitro studies, 4SC-202 has been revealed to induce hyperacetylation of histone H3 in a concentration-dependent fashion with an EC50 values of 1.1μM in HeLa and RKO cell lines. In addition, 4SC-202 has been demonstrated to induce a G2/M cell cycle arrest and enhance in sub G1 cells. In other words, 4SC-202 can induce the apoptotic in NSCLS cell lines. 4SC-202 has been noted to suppress proliferative activity in human cancer cell lines with a mean IC50 of 0.7μM.

In vivo studies, 4SC-202 has shown a good tolerability and dose-dependent effect on anti-tumour activity compared with other inhibitors in the A549NSCLC xenograft model and the RKO27 colon carcinoma model [1].

References:
[1] Henning S W, Doblhofer R, Kohlhof H, et al. 178 Preclinical characterization of 4SC-202, a novel isotype specific HDAC inhibitor[J]. European Journal of Cancer Supplements, 2010, 8(7): 61.