Cancer is one of the world's leading causes of death, as they are complicated and burdensome conditions with complex mechanisms. Despite many newly discovered chemotherapeutics, insufficient selectivity, serious adverse events and development of resistance to therapy remain key drawbacks. Due to cytotoxicity and the development of resistance to established agents, constant research is ongoing to discover new anticancer agents.
Topoisomerase enzymes play an important role in cellular processes and are essential for survival, so their inhibition leads to cell death. They alter the topology of DNA by creating single- or double-stranded transient breaks in the DNA double helix. Based on their structure and mechanism of action, they are divided into type I and type II topoisomerases. Topoisomerase IIα is a known and validated target of many chemotherapeutic drugs. The importance of topoisomerase IIα in proliferating cells suggests that catalytic inhibition of the enzyme may be a useful anticancer strategy. Many sites in the catalytic cycle of topoisomerase are not yet well exploited as binding sites for active substances, leaving much potential for the development of new, more effective and patient-friendly drugs. As fluorescent organic molecules, coumarins have high biological activity, low cytotoxicity and exhibit antitumour activity in several stages of cancer through various mechanisms, including inhibition of enzymes such as topoisomerase.
The experimental part of this master’s thesis is focused on the design of novel fluorophore-labelled catalytic inhibitors of topoisomerase IIα - agents that compete with ATP for the binding site on the N-terminal part of the enzyme, thereby paralysing the catalytic cycle of the enzyme. In the course of the experimental work, new fluorophore-labelled catalytic inhibitors of topoisomerase IIα with 3,4-dichloro-5-methylpyrrolamide and 5-chlorothiophene scaffold were synthesised and analysed. The synthetic routes used were optimised and the products obtained were of satisfactory quantity and purity. The final compounds were evaluated by biochemical testing for enzyme inhibitory activity on DNA topoisomerase IIα at inhibitor concentrations of 10 μM and 100 μM.
|