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Diphenyl ditelluride-induced cell cycle arrest and apoptosis: a relation with topoisomerase I inhibition

Patrícia M Jorge1, Iuri M de Oliveira, Eduardo C Filippi Chiela

  • 1Department of Biophysics, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.

Basic & Clinical Pharmacology & Toxicology
|August 30, 2014
PubMed

Insights

Diphenyl ditelluride (DPDT) reduces cell viability through apoptosis and necrosis. DPDT inhibits topoisomerase I activity, leading to cell cycle arrest and DNA damage.

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Toxicology

Background:

  • Diphenyl ditelluride (DPDT) is a novel molecule with known cytotoxicity and mutagenic properties.
  • The precise mechanisms underlying DPDT-induced reduction in cell viability remain largely unknown.
  • DPDT has been shown to induce DNA strand breaks in Chinese hamster fibroblast (V79) cells.

Purpose of the Study:

  • To elucidate the mechanism of DPDT-induced cytotoxicity in V79 cells.
  • To investigate the effects of DPDT on cell cycle progression, apoptosis, and topoisomerase I activity.
  • To determine the role of topoisomerase enzymes in DPDT toxicity.

Main Methods:

  • MTT assay for cell viability assessment.
  • Morphological analysis and caspase 3/7 activity assays for apoptosis and necrosis detection.
  • Cell cycle analysis, yeast strain sensitivity assays, and DNA relaxation assays for topoisomerase I inhibition studies.

Main Results:

  • DPDT significantly decreased V79 cell viability and induced apoptosis and necrosis.
  • DPDT treatment led to cell cycle arrest in S and sub-G1 phases.
  • Yeast strains deficient in topoisomerase I (Topo I) exhibited increased tolerance to DPDT, and DPDT inhibited human Topo I activity.

Conclusions:

  • DPDT-induced cell cycle arrest and reduced cell viability are likely mediated by the inhibition of topoisomerase I.
  • Topoisomerase 3 (Top3p) may play a role in repairing DPDT-induced DNA damage.
  • DPDT's mechanism of action involves interference with essential DNA processing enzymes.

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