Pharmaceutics (Aug 2021)

Simple and Fast DNA Based Sensor System for Screening of Small-Molecule Compounds Targeting Eukaryotic Topoisomerase 1

  • Kamilla Vandsø Petersen,
  • Asier Selas,
  • Kirstine Mejlstrup Hymøller,
  • Karol Mizielinski,
  • Maria Thorsager,
  • Magnus Stougaard,
  • Concepcion Alonso,
  • Francisco Palacios,
  • Yolanda Pérez-Pertejo,
  • Rosa M. Reguera,
  • Rafael Balaña-Fouce,
  • Birgitta R. Knudsen,
  • Cinzia Tesauro

DOI
https://doi.org/10.3390/pharmaceutics13081255
Journal volume & issue
Vol. 13, no. 8
p. 1255

Abstract

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Background: Eukaryotic topoisomerase 1 is a potential target of anti-parasitic and anti-cancer drugs. Parasites require topoisomerase 1 activity for survival and, consequently, compounds that inhibit topoisomerase 1 activity may be of interest. All effective topoisomerase 1 drugs with anti-cancer activity act by inhibiting the ligation reaction of the enzyme. Screening for topoisomerase 1 targeting drugs, therefore, should involve the possibility of dissecting which step of topoisomerase 1 activity is affected. Methods: Here we present a novel DNA-based assay that allows for screening of the effect of small-molecule compounds targeting the binding/cleavage or the ligation steps of topoisomerase 1 catalysis. This novel assay is based on the detection of a rolling circle amplification product generated from a DNA circle resulting from topoisomerase 1 activity. Results: We show that the binding/cleavage and ligation reactions of topoisomerase 1 can be investigated separately in the presented assay termed REEAD (C|L) and demonstrate that the assay can be used to investigate, which of the individual steps of topoisomerase 1 catalysis are affected by small-molecule compounds. The assay is gel-free and the results can be detected by a simple colorimetric readout method using silver-on-gold precipitation rendering large equipment unnecessary. Conclusion: REEAD (C|L) allows for easy and quantitative investigations of topoisomerase 1 targeting compounds and can be performed in non-specialized laboratories.

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