MS-275

MS-275 (Entinostat) is a potent Histone Deacetylase inhibitor with IC50 value of 0.3 and 8µM for HDAC1 and HDAC3 respectively. It inhibited in vitro cell growth in all cell lines tested with an IC50 ranging from 50 nM to 1.3 uM. MS-275 showed antiproliferative activity against all human breast cancer cell lines examined and induced TbRII mRNA, but not TGF-b type I receptor mRNA. MS-275 caused an accumulation of acetylated histones H3 and H4 in total cellular chromatin. An increase in the accumulation of acetylated histones H3 and H4 was detected in the TbRII promoter after treatment with MS-275.