Navigation Links
Repairing DNA damage: Researchers discover critical process in cancer treatment
Date:11/6/2008

Montreal, November 6, 2008 From the sun's UVA rays to tobacco smoke, our environment is chock-full of DNA-damaging agents that can lead to cancer. Thanks to our body's DNA repair mechanisms, however, the effects of many carcinogens can be reversed thereby preventing the formation of tumours.

Now, according to a new study published in the early online edition of Proceedings of the National Academy of Sciences of the USA (PNAS), scientists from the Universit de Montral and the Maisonneuve-Rosemont Hospital Research Centre have identified a new biochemical pathway which controls DNA repair.

"Our study is the first to identify a regulatory role for the ATR protein in a specific DNA repair system, which is called nucleotide excision repair or NER," says Elliot Drobetsky, senior author and associate professor of immunology and oncology at the Universit de Montral.

"NER is a critical DNA repair system that removes pieces of damaged DNA before these pieces can be converted into genetic mutations that destroy the function of tumour-preventing proteins in the body. Characterizing how the NER system is turned on or off is critical to understanding how tumours develop. In this system, ATR is the key that turns on the repair machinery."

ATR-mediated NER often defective in tumour cells

The scientific team used cultured lung cells to investigate the role of ATR in NER function. They found that inhibiting ATR resulted in a dysfunctional NER system and, during a very critical period of the cell's growth cycle, damaged DNA was not repaired at all.

What's more, they discovered that some tumour cell lines are completely deficient in ATR-mediated NER, which provides solid evidence that the DNA repair function of ATR may be pivotal in cancer development. "Our study reveals an original mechanism to explain how exposure to environmental carcinogens initiate and promote cancer," adds Dr. Drobetsky.

Chemotherapy implications

The goal of conventional chemotherapy is to kill tumour cells leaving normal cells relatively unaffected by damaging their DNA. As such, in what may seem paradoxical, many chemotherapeutic drugs which are used to cure cancer are themselves powerful carcinogens that can also cause cancer.

"As shown in the current study, a non-functional ATR pathway resulting in limited DNA repair may be characteristic of many tumour cell types, but not of normal noncancerous cells. Determining if the NER system is working in patient tumours may therefore be an important first step to chemotherapy prescribing practices," says Yannick Auclair, the study's lead author and a PhD student at the Universit de Montral.

Any tumours identified as defective in ATR-mediated repair are expected to respond extremely well to chemotherapy, because the cells in these tumours would be extremely hypersensitive to certain anti-cancer drugs unlike normal cells in the rest of the body.

"These findings open a whole new area of research," says Dr. Drobetsky. "Our data harbour critical implications not only for understanding how cancer develops but also for devising new strategies to greatly improve cancer treatment."


'/>"/>

Contact: Sylvain-Jacques Desjardins
sylvain-jacques.desjardins@umontreal.ca
514-343-7593
University of Montreal
Source:Eurekalert

Related biology news :

1. Corn researchers discover novel gene shut-off mechanisms
2. Researchers at UH explore patient preferences for personalized medicine
3. UC Davis researchers discover a key to aggressive breast cancer
4. Caltech-led researchers find negative cues from appearance alone matter for real elections
5. ASU researchers receive NIH awards for studies of malaria and emergent disease
6. Stanford researchers: Global warming is killing frogs and salamanders in Yellowstone Park
7. Syracuse University researchers discover new way to attack some forms of leukemia
8. Researchers apply systems biology and glycomics to study human inflammatory diseases
9. Researchers at UH explore use of fat cells as heart attack therapy
10. GUMC researchers hone in on new strategy to treat common infection
11. Ben-Gurion University of the Negev researchers help find that hypnosis can induce synesthesia
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:1/22/2016)... , Jan. 22, 2016 ... the addition of the "Global Biometrics ... to their offering. --> ... the "Global Biometrics Market in Retail ... --> Research and Markets ...
(Date:1/20/2016)... --  MedNet Solutions , an innovative SaaS-based eClinical technology ... is pleased to announce the attainment of record-setting corporate ... of the company,s laser focus on (and growing international ... comprehensive, easy-to-use and highly affordable cloud-based technology platform. ... growth achievements in 2015 include: , Record ...
(Date:1/15/2016)... JUAN, Puerto Rico , Jan. 15, 2016 /PRNewswire/ ... companies big and small to find new ways to ... driven culture. iOS and Android ... device based on biometrics, transforming it into a hardware ... request that users swipe their fingerprint on their KodeKey ...
Breaking Biology News(10 mins):
(Date:2/8/2016)... ANGELES , Feb. 8, 2016  CytRx ... and development company specializing in oncology, today announced ... and security agreement with Hercules Technology Growth Capital, ... to $40 million in financing. ... the first $25 million of financing under the ...
(Date:2/8/2016)... ... February 08, 2016 , ... Information Management Services ( ... The upgrade represents a completely new technical foundation and is so significant it ... responsive design interface, significantly increased speed for search results, a streamlined layout and a ...
(Date:2/8/2016)... FLINT, Mich. , Feb. 8, 2016  Diplomat Pharmacy, Inc. (NYSE: DPLO) announced today that ... as a specialty pharmacy resource–user-centric, story-driven, knowledge-based and mobile-friendly. ... ... ... "The ...
(Date:2/5/2016)... , Feb. 5, 2016  In the pharmaceutical ... for a host of launch activities including the identification ... this launch activity is especially high in the oncology ... Best Practices and the Role of Medical Affairs ... companies focused on oncology therapies find better ways to ...
Breaking Biology Technology: