HPOB

HPOB is a hydroxamic acid-based small-molecule that selectively inhibits histone deacetylase 6 (HDAC6). The IC₅₀ for inhibition of recombinant HDAC6 is 56 nM. It inhibits the growth of normal human foreskin fibroblast (HFS) and transformed (LNCaP, human prostate adenocarcinoma, A549 lung adenocarcinoma, and U87 glioblastoma) cells in a concentration-dependent manner at 8 μM, 16 μM, or 32 μM, but does not induce cell death. HPOB causes accumulation of acetylated α-tubulin in these cells. HPOB enhances cell death induced by the anticancer drugs etoposide, doxorubicin and SAHA.