Effect of poly(ADP-ribosyl)ation inhibitors on the genotoxic effects of the boron neutron capture reaction

Mutat Res. 2005 May 2;583(1):36-48. doi: 10.1016/j.mrgentox.2005.01.015. Epub 2005 Apr 21.

Abstract

The boron neutron capture (BNC) reaction results from the interaction of 10B with low-energy thermal neutrons and gives rise to highly damaging lithium and alpha-particles. In this work the genotoxicity caused by the BNC reaction in V79 Chinese hamster cells was evaluated in the presence of poly(ADP-ribosyl)ation inhibitors. Poly(ADP-ribose) polymerase-1 (PARP-1), the most important member of the PARP enzyme family, is considered to be a constitutive factor of the DNA damage surveillance network present in eukaryotic cells, acting through a DNA break sensor function. Inhibition of poly(ADP-ribosyl)ation was achieved with the classical compound 3-aminobenzamide (3-AB), and with two novel and very potent inhibitors, 5-aminoisoquinolinone (5-AIQ) and PJ-34. Dose-response increases in the frequencies of aberrant cells excluding gaps (%ACEG) and chromosomal aberrations excluding gaps per cell (CAEG/cell) were observed for increasing exposures to the BNC reaction. The presence of 3-AB did not increase the %ACEG or CAEG/cell, nor did it change the pattern of the induced chromosomal aberrations. Results with 5-AIQ and PJ-34 were in agreement with the results obtained with 3-AB. We further studied the combined effect of a PARP inhibitor and a DNA-dependent protein kinase (DNA-PK) inhibitors (3-AB and wortmannin, respectively) on the genotoxicity of the BNC reaction, by use of the cytokinesis-block micronucleus assay. DNA-PK is also activated by DNA breaks and binds DNA ends, playing a role of utmost importance in the repair of double-strand breaks. Our results show that the inhibition of poly(ADP-ribosyl)ation does not particularly modify the genotoxicity of the BNC reaction, and that PARP inhibition together with a concomitant inhibition of DNA-PK revealed barely the same sensitizing effect as DNA-PK inhibition per se.

MeSH terms

  • Alpha Particles
  • Animals
  • Boron Neutron Capture Therapy / adverse effects*
  • Cell Culture Techniques
  • Cricetinae
  • Cricetulus
  • DNA Damage*
  • DNA-Activated Protein Kinase
  • DNA-Binding Proteins / pharmacology
  • Fibroblasts
  • Humans
  • Mutagenicity Tests
  • Nuclear Proteins
  • Poly (ADP-Ribose) Polymerase-1
  • Poly Adenosine Diphosphate Ribose / antagonists & inhibitors*
  • Poly Adenosine Diphosphate Ribose / pharmacology*
  • Poly(ADP-ribose) Polymerases / pharmacology
  • Protein Serine-Threonine Kinases / pharmacology

Substances

  • DNA-Binding Proteins
  • Nuclear Proteins
  • Poly Adenosine Diphosphate Ribose
  • PARP1 protein, human
  • Poly (ADP-Ribose) Polymerase-1
  • Poly(ADP-ribose) Polymerases
  • DNA-Activated Protein Kinase
  • PRKDC protein, human
  • Protein Serine-Threonine Kinases