New compounds identified as inhibitors of DNA topoisomerase 1

Andrés Aguilera's laboratory, in collaboration with that of Ralf Wellinger (both professors in the Department of Genetics at the University of Seville in CABIMER) and with PharmaMAR, has identified two natural compounds, patulin and xestoquinol, as new inhibitors of the enzyme topoisomerase 1, a key element in the correct functioning of DNA. The finding, published in the journal Proceedings of the National Academy of Sciences of the United States of America , opens new doors to understanding and treating diseases related to damage to genetic material.

DNA topoisomerase 1 is an enzyme present in all organisms, essential for cell proliferation. Its function is based on two catalytic steps: firstly, it cuts and then relinks the DNA, thus relaxing the topological stress generated during replication and transcription; secondly, the inhibitors prevent the cuts in the DNA from being ligated, leaving them open. In this way, they act as topoisomerase poisons, and are used as anticancer drugs.

However, reliable inhibitors of the first step, DNA cleavage, are not available, despite their potential in basic research and possible applications in medicine. According to this research, patulin and xestoquinol inhibit the first catalytic activity of topoisomerase I in vitro, in yeast and human cells.

The study, first authored by Emanuela Tumini, PhD, is published in the journal Proceedings of the National Academy of Sciences of the United States of America and identifies a new class of inhibitors that opens new perspectives in basic and cancer research.

The research was mainly funded by a State Research Agency RETOS project.