A Fully Synthetic Therapeutic Vaccine Candidate Targeting Carcinoma-Associated Tn Carbohydrate Antigen Induces Tumor-Specific Antibodies in Nonhuman Primates

Abstract
Histone deacetylases (HDACs) mediate changes in nucleosome conformation and are important in the regulation of gene expression. HDACs are involved in cell cycle progression and differentiation, and their deregulation is associated with several cancers. HDAC inhibitors have emerged recently as promising chemotherapeutic agents. One such agent, suberoylanilide hydroxamic acid, is a potent inhibitor of HDACs that causes growth arrest, differentiation, and/or apoptosis of many tumor types in vitro and in vivo. Because of its low toxicity, suberoylanilide hydroxamic acid is currently in clinical trials for the treatment of cancer. HDAC inhibitors induce the expression of S-hydroxyoctadecadienoic acid levels, growth inhibition, differentiation, and apoptosis observed with these cells. Furthermore, specific inhibition of 15-lipoxygenase-1 significantly reduced the suberoylanilide hydroxamic acid-induced effects. These novel findings are the first demonstration of a mechanistic link between the induction of 15-lipoxygenase-1 by a HDAC inhibitor and apoptosis in cancer cells. This result has important implications for the study of suberoylanilide hydroxamic acid and other HDAC inhibitors in the prevention and therapy of colorectal cancer and supports future investigations of the mechanisms by which HDAC inhibitors up-regulate 15-lipoxygenase-1.