Background: The family of DNA topoisomerases comprises a group of enzymes
that catalyse the induction of topological changes to DNA. These enzymes play a role in the
cell replication machinery and are, therefore, important targets for anticancer drugs - with human
DNA topoisomerase IIα being one of the most prominent. Active compounds targeting
this enzyme are classified into two groups with diverse mechanisms of action: DNA poisons
act by stabilizing a covalent cleavage complex between DNA and the topoisomerase enzyme,
transforming it into a cellular toxin, while the second diverse group of catalytic inhibitors,
provides novel inhibition avenues for tackling this enzyme due to frequent occurrence of side
effects observed during the DNA poison therapy.
Methods: Based on a comprehensive literature search we present an overview of available
bioassays and in silico methods in the identification of human DNA topoisomerase IIα inhibitors.
Results and Conclusion: A comprehensive outline of the available methods and approaches
that explore in detail the in vitro mechanistic and functional aspects of the topoisomerase IIα
inhibition of both topo IIα inhibitor groups is presented. The utilized in vitro cell-based assays
and in vivo studies to further explore the validated topo IIα inhibitors in subsequent preclinical
stages of the drug discovery are discussed. The potential of in silico methods in topoisomerase
IIα inhibitor discovery is outlined. A list of practical guidelines was compiled to aid new as
well experienced researchers in how to optimally approach the design of targeted inhibitors
and validation in the preclinical drug development stages.