Synthesis and biological evaluation of glucuronide prodrugs of the histone deacetylase inhibitor CI-994 for application in selective cancer chemotherapy.

Two glucuronide prodrugs of the histone deacetylase inhibitor CI-994 were synthesized. These compounds were found to be soluble in aqueous media and stable under physiological conditions. The carbamoyl derivatisation of CI-994 significantly decreased its toxicity towards NCI-H661 lung cancer cells. Prodrug incubation with beta-glucuronidase in the culture media led efficiently to the release of the parent drug and thereby restoring its ability to decrease cell proliferation, to inhibit HDAC and to induce E-Cadherin expression.