Current Research in Polypharmacology for Cancer Treatment Using Dual-Target Histone Deacetylase Inhibitors

The review covers research on dual-target antitumor agents over the past five years. One of the targets is histone deacetylases (HDACs), while the second potential target is a protein group located both on the membrane surface (phosphatidylinositol 3-kinase (PI3K), anaplastic lymphoma kinase (ALK), receptor tyrosine kinase (AXL), tyrosine protein kinase (HER2), FMS-like tyrosine kinase (FLT3), and vascular endothelial growth factor receptor (VEGFR2)) and in the nucleus (serine/threonine protein kinase Wee1, DNA methyltransferase (DNMT), dual-specificity phosphatase (CDC25A), an enzyme from the cyclin-dependent kinase family (CDK9), dual-specificity tyrosine-serine/threonine kinase (DYRK2), and BET family proteins (BRD4, BD1, and BD2)). This review presents the results of studies on the inhibitory activity of various HDAC isoforms and other enzymes, as well as in vitro cytotoxicity studies on both neoplastic and healthy cells. It also includes selectivity studies, in vivo experiments (changes in tumor volume in mice) and oral bioavailability assessments. The review also describes the chemical structures of several dual-target agents and identifies the molecular fragments responsible for inhibiting different targets. Based on the studies reviewed in this paper, it can be concluded that some dual inhibitors have superior in vitro cytotoxicity and exhibit selectivity towards some tumor cells compared to monofunctional reference compounds. These findings may be useful for molecular design in the field of polypharmacology, with the aim of developing new dual-target molecules that exhibit improved antitumor activity and selectivity towards neoplastic cells.