The development of cancerous tumours is highly dependent on the nutrients the tumours receive through the blood. The team of Dr. Janusz Rak, of the Research Institute of the McGill University Health Centre (MUHC) at the Montreal Children’s Hospital, including Dr. Khalid Al-Nedawi and Brian Meehan, has just discovered a new mechanism that tumours use to stimulate the growth of the blood vessels that feed them. The researchers have also proposed a new way to control this process, which may translate into future therapies. These findings were published this week in the Proceedings of the National Academy of Sciences (PNAS).

An innovative method…

According to the researchers, tumour cells can release “bubbles” called microvesicles, which allow the tumours to communicate with the endothelial cells of blood vessels and stimulate changes in their behaviour. The microvesicles are armed with specific cancer proteins as they leave the tumour. When they are taken up by endothelial cells, the specific cancer proteins that they carry can trigger mechanisms that promote the abnormal formation of new blood vessels. The vessels then grow towards the tumour and supply it with the nutrients it requires to grow.

“We had already demonstrated the existence of these vesicles as well as their importance in the communication process between cancer cells and their environment. But this new discovery is much more targeted and represents a new direction in terms of therapy,” said a delighted Dr. Rak.

… to starve tumors

In fact, a family of molecules derived from annexin V seems to effectively fight this process and ultimately may help “starve” the tumour. “The molecule we used is effective both in vitro and in vivo. It prevents the formation of new blood vessels in mice with cancer and therefore strongly inhibits tumour growth,” explained Dr. Rak.

Called Diannexin, this molecule acts to block the in vitro fusion of vesicles and endothelial cells. In mice with cancer, Diannexin works to slow blood vessel growth towards the tumour, resulting in anti-cancer effects. This finding is particularly important considering the treatment was applied in isolation without additional chemotherapy. If combined with other agents, this new way of treating cancer may be even more potent.

Diannexin is currently being developed as an antithrombotic medication. It would therefore be possible to use it safely for different types of pathologies.

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Funding

This project was funded through a grant from the Canadian Cancer Society Research Institute and the Fonds de la recherche en santé du Québec.

Dr. Janusz Rak

Dr. Janusz Rak is a researcher in the Cancer Axis at the Research Institute of the McGill University Health Centre at the Montreal Children’s Hospital. He is also a Jack Cole Professor in Pediatric Oncology at McGill University.

Partners

This project was carried out in partnership with Dr. R.S. Kerbel of the Sunnybrook Health Sciences Centre, University of Toronto, and Dr. A.C. Allison of Alavita Pharmaceuticals Inc.

Find this press release, with the original article and a short audio document by following this link : http://www.muhc.ca/media/news/

The Research Institute of the McGill University Health Centre (RI MUHC) is a world-renowned biomedical and health-care hospital research centre. Located in Montreal, Quebec, the institute is the research arm of the MUHC, the university health center affiliated with the Faculty of Medicine at McGill University. The institute supports over 600 researchers, nearly 1200 graduate and post-doctoral students and operates more than 300 laboratories devoted to a broad spectrum of fundamental and clinical research. The Research Institute operates at the forefront of knowledge, innovation and technology and is inextricably linked to the clinical programs of the MUHC, ensuring that patients benefit directly from the latest research-based knowledge.

The Research Institute of the MUHC is supported in part by the Fonds de la recherche en santé du Québec.

The Montreal Children’s Hospital (MCH) is the pediatric teaching hospital of the McGill University Health Centre and is affiliated with McGill University. The MCH is a leader in providing a broad spectrum of highly specialized care to newborns, children, and adolescents from across Quebec. Our areas of medical expertise include programs in brain development/behaviour, cardiovascular sciences, critical care, medical genetics and oncology, tertiary medical and surgical services, and trauma care. Fully bilingual, the hospital also promotes multiculturalism and serves an increasingly diverse community in more than 50 languages. The Montreal Children’s Hospital sets itself apart with its team approach to innovative patient care. Our health professionals and staff are dedicated to ensuring children and their families receive exceptional health care in a friendly and supportive environment.

For more information please contact:

Isabelle Kling
Communications Coordinator (research)
MUHC Public Relations and Communications
(514) 843 1560
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Contact: Isabelle Kling
.(JavaScript must be enabled to view this email address)
514-843-1560
McGill University Health Centre