How the body aids and abets the spread of cancer

RI-MUHC researchers ID new mode of cancer progression

Montreal, July 1st 2013 – The very system that is meant to protect the body from invasion may be a traitor. These new findings of a study, led by investigators at the Research Institute of the McGill University Health Centre (RI-MUHC), reveal that infection-fighting white blood cells play a role in activating cancer cells and facilitating their spread to secondary tumours. This research, published today in the Journal of Clinical Investigation has significant implications for both the diagnosis and treatment of cancer.


Dr. Lorenzo Ferri (left) and Dr. Jonathan Cools-Lartigue (right) are looking at a human stomach cancer specimen. Credits: Pierre Dubois, McGill University Health Centre

“We are the first to identify this entirely new way that cancer spreads,” says senior author Dr. Lorenzo Ferri, MUHC director of the Division of Thoracic Surgery and the Upper Gastrointestinal (GI) Cancer Program. “What’s equally exciting is medications already exist that are being used for other non-cancer diseases, which may prevent this mechanism of cancer spread or metastasis.” According to Dr. Ferri, the next steps are to validate if these medicines will work for the prevention and treatment of cancer metastasis, and then to determine the optimal timing and dosing.

Linking infection, inflammation and metastasis

“Our first clue of this association was from our previous research, which showed that severe infection in cancer patients after surgery results in a higher chance that patients will have the cancer return in the form of cancer metastasis,” says Dr. Ferri who is also an Associate Member of the Rosalind and Morris Goodman Cancer Research Centre and Associate Professor in the Department of Oncology at McGill University. “This led us to investigate the cellular players in the infection, notably neutrophils, the first and most numerous of the white blood cells that are used by the immune system fight off infections.”

Dr. Ferri and his colleagues from McGill University and the University of Calgary used both cultured cells and mouse models of cancer to show that there is a relationship between infection, a white blood cell response (inflammation) and metastasis. A web-like network called Neutrophils Extracellular Traps (NETs), is produced by white blood cells (neutrophils) in response to an infection and this normally traps and kills invading pathogens, such as bacteria.

 


Cancer cells (in red) being trapped by NETs (in green) developed by white blood cells (in blue). Credits: Dr. Cools-Lartigue and Dr. Ferri

“We demonstrated that in the case of infected animals with cancer, the neutrophil web (NETs) also trapped circulating cancer cells,” adds Dr. Jonathan Cools-Lartigue, first author of the study, and a PhD student from the LD MacLean Surgical Research Laboratories at McGill University. “Instead of killing the cancer cells, these webs activated the cancer cells and made them more likely to develop secondary tumours, or metastasis.”

 

No web equals better outcome

The researchers went one step further and showed that breaking down the neutrophil web is achievable by using certain medication. Furthermore, in mice with cancer, markedly less tumour growth and metastasis occurred after the medication was administered. This finding was true for a number of different cancer types, suggesting that neutrophil webs may be a common pathway involved in the spreading of many cancers.

“Our study reflects a major change in how we think about cancer progression,” says Dr. Ferri. “And, more importantly, how we can treat it.”

Caption: Lung cancer cells (shown in red) are flowing over white blood cells or neutrophils (not visible). White blood cells have been stimulated to extrude their DNA and form NETs (shown in green). As the white blood cells produce NETs, cancer cells can be seen to be trapped within the DNA webs. Addition of a drug that breaks down NETs results in the release of trapped tumour cells.

 

Video credits: Dr. Lorenzo Ferri and Dr. Jonathan Cools-Lartigue

About the study: 

This work was supported by a grant from the Canadian Cancer Society Research Institute.

The study, Neutrophil extracellular traps (NETs) sequester circulating tumor cells and promote the development of metastasis was authored by Jonathan Cools-Lartigue (First author), Jonathan Spicer, Stephen Gowing, Simon Chow, Betty Giannias, France Bourdeau, (LD MacLean Surgical Research Laboratories, Department of Surgery, McGill University, Montreal); Lorenzo Ferri (LD MacLean Surgical Research Laboratories, McGill and RI-MUHC); Braedon McDonald and Paul Kubes (Calvin, Phoebe, and Joan Snyder Institute, University of Calgary, Calgary). Link: Scientific article

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Dr. Lorenzo Ferri and Dr. Jonathan Cools-Lartigue  (click to enlarge, and then right-click to save)

Photo credits: Pierre Dubois, McGill University Health Centre

Media contact:

Julie Robert
Public Affairs and Strategic Planning
McGill University Health Centre
514 934 1934 ext. 71381

julie [dot] robert [at] muhc [dot] mcgill [dot] ca

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