Authors: Lebel M; Lavoie J; Gaudreault I; Bronsard M; Drouin R
Abstract: Werner syndrome is a rare disorder characterized by the premature onset of a number of age-related diseases. The gene responsible for Werner syndrome encodes a DNA helicase/exonuclease protein. Participation in a replication complex is among the several functions postulated for the WRN protein. The poly(ADP-ribose) polymerase-1 (PARP-1) enzyme, which is known to bind to DNA strand breaks, is also associated with the DNA replication complex. To determine whether Wrn and PARP-1 enzymes act in concert during cell growth, mice with a mutation in the helicase domain of the Wrn gene (Wrn(Deltahel/Deltahel) mice) were crossed to PARP-1-null mice. Both Wrn(Deltahel/Deltahel) and PARP-1-null/Wrn(Deltahel/Deltahel) cohorts developed more neoplasms than wild-type animals. The tumor spectrum was the same between PARP-1-null/Wrn(Deltahel/Deltahel) mice and Wrn mutants. However, PARP-1-null/Wrn(Deltahel/Deltahel) mice developed neoplasms at a younger age. Mouse embryonic fibroblasts derived from such PARP-1-null/Wrn(Deltahel/Deltahel) mice stop dividing abruptly unlike Wrn(Deltahel/Deltahel) or PARP-1-null cells. PARP-1-null/Wrn(Deltahel/Deltahel) fibroblasts were distinguished by an increased frequency of chromatid breaks, complex chromosomal rearrangements, and fragmentation. Finally, experiments have indicated that the PARP-1 enzyme co-immunoprecipitates with the WRN protein in human 293 embryonic kidney cells. These results suggest that Wrn and PARP-1 enzymes may be part of a complex involved in the processing of DNA breaks.
Keywords: Aging/genetics/*physiology; Animals; Chromatids/*genetics; *Chromosome Aberrations; DNA Helicases/deficiency/*genetics; DNA Primers; Disease Models, Animal; Exodeoxyribonucleases; Female; *Gene Rearrangement; Humans; Metaphase; Mice; Mice, Knockout; Mutation; Neoplasms/*genetics/pathology/*prevention & control; Poly(ADP-ribose) Polymerases/deficiency/*genetics; RecQ Helicases; Werner Syndrome/genetics|
Journal: The American journal of pathology Volume: 162 Issue: 5 Pages: 1559-69 Date: April 23, 2003 PMID: 12707040 |
Lebel M, Lavoie J, Gaudreault I, Bronsard M, Drouin R (2003) Genetic cooperation between the Werner syndrome protein and poly(ADP-ribose) polymerase-1 in preventing chromatid breaks, complex chromosomal rearrangements, and cancer in mice. The American journal of pathology 162: 1559-69.
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