Enzyme inhibition as a key target for the development of novel metal-based anti-cancer therapeutics.

Historically, DNA has been the target for many metal-based anti-cancer drugs, but drawbacks of prevailing therapies have stimulated the search for new molecular targets which may present unique opportunities for therapeutic exploitation. Enzyme inhibition has recently been identified as an alternative and significant target. The pursuit of novel metallodrug candidates that selectively target enzymes is now the subject of intense investigation in medicinal bioinorganic chemistry and chemical biology. In the field of drug design, it is recognised by many that exploiting the structural and chemical diversity of metal ions for the identification of potential hit and lead candidates can dramatically increase the number of possible drug candidates that may be added to the already abundant armoury of chemotherapeutic agents. This review will focus on recent key advancements in enzyme inhibition as a key target for the development of novel metal-based anti-cancer therapeutics. The enormous clinical success of classical platinum drugs, amongst others, coupled with the wealth of knowledge accumulated in recent years on enzyme structure and function, has undoubtedly been the impetus behind the development of new metallodrug candidates with enzyme inhibitory properties. Recent trends in this field will be reviewed with a particular emphasis on metal complexes that inhibit protein and lipid kinases, matrix metalloproteases, telomerases, topoisomerases, glutathione-S-transferases, and histone deacetylases.