Histone deacetylase inhibitor based prodrugs

Histone deacetylases (HDACs) are a family of enzymes which play important roles in the development and progression of cancers. Inhibition of HDACs has been widely studied as a therapeutic strategy in the discovery of anticancer drugs. HDAC inhibitors (HDACIs) have exhibited potency against a variety of cancer types, and four of them have been approved by the US FDA for cancer treatment. However, the clinical benefits of current HDACIs is limited by the insufficient physicochemical property, selectivity and potency. To improve the clinical potential of HDACIs, the prodrug strategy had been utilized to improve the in vivo pharmacokinetic and pharmacodynamic performances of HDACIs. Enhancements in the stability, water solubility, lipophilicity, oral bioavailability and tumor cell selectivity were reported by various studies. Herein, the development of different kinds of HDACI-based prodrug is summarized for the further structural modification of HDACIs with high potential to be drug candidates.

Antipsychotic dopamine receptor antagonists, cancer, and cancer stem cells

Cancer is one of the deadliest diseases in the world. Despite extensive studies, treating metastatic cancers remains challenging. Years of research have linked a rare set of cells known as cancer stem cells (CSCs) to drug resistance, leading to the suggestion that eradication of CSCs might be an effective therapeutic strategy. However, few drug candidates are active against CSCs. New drug discovery is often a lengthy process. Drug screening has been advantageous in identifying drug candidates. Current understanding of cancer biology has revealed various clues to target cancer from different points of view. Many studies have found dopamine receptors (DRs) in various cancers. Therefore, DR antagonists have attracted a lot of attention in cancer research. Recently, a group of antipsychotic DR antagonists has been demonstrated to possess remarkable abilities to restrain and sensitize CSCs to existing chemotherapeutics by a process called differentiation approach. In this review, we will describe current aspects of CSC-targeting therapeutics, antipsychotic DR antagonists, and their extraordinary abilities to fight cancer.