Public Release:  Canadian research breakthrough holds promise for development of effective cancer therapies

Scientists identify new target for cancer cure

University of Montreal

Montreal, September 2, 2009 - Researchers Dr. Marc Therrien at the Institute for Research in Immunology and Cancer (IRIC) of the Université de Montréal, and Dr. Frank Sicheri, at the Samuel Lunenfeld Research Institute of Mount Sinai Hospital in Toronto, have discovered a new target that may be instrumental in the development of new, more effective cancer therapies.

A recent article co-authored by Drs. Therrien and Sicheri and published in the leading scientific journal Nature sheds new light on the activation mechanism of the RAF protein kinase which, when mutated, is responsible for more than 25 per cent of cancers. Understanding this mechanism may lead to novel anti-cancer agents designed to minimize the toxic side effects caused by chemotherapy.

The RAF family of kinases regulates various cellular processes including cell growth, differentiation and survival. The Therrien-Sicheri team is the first to show that the dimerization, or combination, of two RAF proteins is essential to its activation. Inhibiting the dimerization of RAF may therefore block its activation, thus stopping cancer cells from growing. The study exposes not only the activation mechanism of RAF, but potentially the mechanisms that control other protein kinases, a large number of which are linked to cancer and other diseases such as diabetes, hypertension and neurodegeneration.

"Basic researchers believe that one of the most promising strategies to finding lifelong cures for cancers lies in understanding the molecular underpinnings specific to cancer cells," explains Dr. Therrien, "It is hoped that this will translate to the development of inhibitors tailored to specific molecular defects and, as a result, should increase the effectiveness of new target-based cancer therapies."

"Protein kinases are the targets for some of the most successful anti-cancer drugs in the clinic," says Dr. Sicheri. "Now that we have discovered how to turn off the RAF protein without interfering with other proteins, we may be able to design drugs that have unprecedented precision in targeting cancer cells while reducing the toxic side effects for patients."

The Therrien-Sicheri team intends to jointly pursue work in this area to identify drug-like molecules to block the dimerization process of RAF, which may possibly lead to the discovery of new classes of anti-cancer agents.

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Researchers & Financing
Dr. Marc Therrien holds the Canada Research Chair in Intracellular Signalling. Dr. Frank Sicheri was the recipient of a Canadian Cancer Society Research Scientist Award. The research received funding from the Canadian Cancer Society and the Canadian Institutes for Health Research.

About the Institute for Research in Immunology and Cancer
IRIC is a state-of-the-art biomedical research centre at the Université de Montréal. IRIC is committed to finding novel cancer therapeutics through multidisciplinary approaches. Its team of more than 350 scientists and professionals work on various aspects of cancer research from basic science through to clinical applications. For more information about IRIC, please visit www.iric.ca. For more information about Dr. Marc Therrien, please visit http://www.iric.ca/Recherche/Chercheurs/Therrien_M_EN.html.

About the Samuel Lunenfeld Research Institute of Mount Sinai Hospital
The Samuel Lunenfeld Research Institute of Mount Sinai Hospital, a University of Toronto affiliated research centre established in 1985, is one of the world's premier centres in biomedical research. Thirty-four principal investigators lead research in diabetes, cancer biology, epidemiology, stem cell research, women's and infants' health, neurobiology and systems biology. For more information on the Samuel Lunenfeld Research Institute, please visit www.lunenfeld.ca.

Paper cited:
Thanashan Rajakulendran, Malha Sahmi, Martin Lefrançois, Frank Sicheri and Marc Therrien."A Dimerization-Dependent Mechanism Drives Raf Catalytic Activation". Nature, prepublished online 02 Sept, 2009; DOI: 10.1038/nature08314

On the Web:
About the Université de Montréal: http://www.umontreal.ca/english

Media contacts:

For Dr. Therrien, please contact:
Carolyne Lord
Media Relations Officer
Institute for Research in Immunology and Cancer, Université de Montréal
Telephone: 514-343-7282
Email: carolyne.lord@umontreal.ca

For Dr. Sicheri, please contact:
Melissa McDermott
Media and Communications Specialist
Mount Sinai Hospital
Telephone: 416-586-4800 ext. 8306
Email: mmcdermott@mtsinai.on.ca

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