Cancer can be considered a disease of genetic instability. DNA damage triggers a complex response that includes cell cycle arrest and coordinated activation of DNA repair. Failure to activate or to coordinate the DNA-damage induced signal transduction pathways can lead to chromosome breakage and loss, and to the propagation of mutations. Indeed, several cancer-prone syndromes reflect defects in the DNA damage response and are characterized by genetic instability. These include, but are not limited to, Ataxia- Telangiectasia, Nijmegen Breakage Syndrome, Ataxia-Telangiectasia Like Disorder, Li-Fraumeni Syndrome and familial forms of breast and cervical cancers. Our long-term objective is to understand the molecular nature of the signal transduction pathways activated following DNA damage. To that goal, we have established unique cell-free systems derived from Xenopus eggs that faithfully recapitulate several aspects of the DNA damage response. We will use these cell-free systems to screen for proteins that are modified in presence of double strand breaks (DSBs). Next, we will investigate the role in the DNA damage response of a candidate gene we have identified in a pilot screen and of additional genes we will isolate. We will screen a chemical library for compounds that interfere with the in vitro activation of ATM/ATR protein kinases, an early step of the DNA damage response. The compounds identified will be further validated and their activity will be tested in a variety of assays performed in Xenopus cell-free systems. We anticipate that these studies will help identify novel components of the biochemical pathways activated by DNA damage and shed light on the nature of the biochemical steps constituting these pathways. These studies will provide valuable information on how the DNA damage response can be impaired or lost in the case of cancer and will help identify drugs that influence the DNA damage response.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA095866-03
Application #
6796277
Study Section
Special Emphasis Panel (ZCA1-SRRB-U (J1))
Program Officer
Forry, Suzanne L
Project Start
2002-09-05
Project End
2007-08-31
Budget Start
2004-09-01
Budget End
2005-08-31
Support Year
3
Fiscal Year
2004
Total Cost
$232,988
Indirect Cost
Name
Columbia University (N.Y.)
Department
Genetics
Type
Schools of Medicine
DUNS #
621889815
City
New York
State
NY
Country
United States
Zip Code
10032
Dupre, Aude; Boyer-Chatenet, Louise; Sattler, Rose M et al. (2008) A forward chemical genetic screen reveals an inhibitor of the Mre11-Rad50-Nbs1 complex. Nat Chem Biol 4:119-25
Di Virgilio, Michela; Gautier, Jean (2005) Repair of double-strand breaks by nonhomologous end joining in the absence of Mre11. J Cell Biol 171:765-71
Costanzo, Vincenzo; Robertson, Kirsten; Gautier, Jean (2004) Xenopus cell-free extracts to study the DNA damage response. Methods Mol Biol 280:213-27
Costanzo, Vincenzo; Paull, Tanya; Gottesman, Max et al. (2004) Mre11 assembles linear DNA fragments into DNA damage signaling complexes. PLoS Biol 2:E110