ABSTRACT
CRA-026440 is a novel, broad-spectrum, hydroxamic acid-based inhibitor of histone deacetylase (HDAC) that shows antitumor and antiangiogenic activities in vitro and in vivo preclinically. CRA-026440 inhibited pure recombinant isozymes HDAC1, HDAC2, HDAC3/SMRT, HDAC6, HDAC8, and HDAC10 in the nanomolar range. Treatment of cultured tumor cell lines grown in vitro with CRA-026440 resulted in the accumulation of acetylated histone and acetylated tubulin, leading to an inhibition of tumor cell growth and the induction of apoptosis. CRA-026440 inhibited ex vivo angiogenesis in a dose-dependent manner. CRA-026440 parenterally given to mice harboring HCT116 or U937 human tumor xenografts resulted in a statistically significant reduction in tumor growth. CRA-026440, when used in combination with Avastin, achieved greater preclinical efficacy in HCT 116 colorectal tumor model. Inhibition of tumor growth was accompanied by an increase in the acetylation of alpha-tubulin in peripheral blood mononuclear cells and an alteration in the expression of many genes in the tumors, including several involved in angiogenesis, apoptosis, and cell growth. These results reveal CRA-026440 to be a novel HDAC inhibitor with potent antitumor activity.
Subject(s)
Angiogenesis Inhibitors/pharmacology , Antineoplastic Agents/pharmacology , Enzyme Inhibitors/pharmacology , Histone Deacetylase Inhibitors , Hydroxamic Acids/pharmacology , Indoles/pharmacology , Neoplasms/enzymology , Acetylation , Angiogenesis Inhibitors/chemistry , Angiogenesis Inhibitors/pharmacokinetics , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacokinetics , Apoptosis , Cell Line, Tumor , Cell Proliferation/drug effects , Cyclin-Dependent Kinase Inhibitor p21/drug effects , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacokinetics , Female , Gene Expression/drug effects , Gene Expression Profiling , Histones/drug effects , Humans , Hydroxamic Acids/chemistry , Indoles/chemistry , Mice , Mice, Inbred BALB C , Neoplasms/blood supply , Neoplasms/genetics , Poly Adenosine Diphosphate Ribose/adverse effects , Tubulin/drug effects , Tubulin/metabolism , Xenograft Model Antitumor AssaysABSTRACT
Analogues of the tetrahydroisoquinoline family of antitumor antibiotics, 3-epi-jorumycin (3) and 3-epi-renieramycin G (4), in addition to their respective parent natural products (-)-jorumycin (1) and (-)-renieramycin G (2) were evaluated against both human colon (HCT-116) and human lung (A549) cancer cell lines. (-)-Jorumycin (1) displayed potent growth inhibition with GI50 values in the low nanomolar range (1.9-24.3 nM), while compounds 2-4 were found to be substantially less cytotoxic (GI50 0.6-14.0 microM).
