Preventing metastases: the search for a vaccine

Prevention of a cancer by a vaccineZoomZoom
© Armand-Frappier Museum

Article published in the Courrier Laval February 26, 2006.

Health Canada estimates that in 2005, 149,0000 new cases of cancer and 69,500 deaths due to this disease were recorded in this country. But what exactly is this disease whose mere mention makes everyone shudder?

Let us first note that cancers are characterized by the appearance of abnormal cells that have acquired the property to divide quickly and uncontrollably. When the immune system cannot identify and destroy a newly formed cancer cell, the latter multiplies and the cells it produces lead to a primary tumor. At this stage, the tumor is usually benign and can be treated effectively, in the vast majority of cases using, for example, surgery or radiotherapy.

If the tumor is not treated in a timely manner, the cancer cells continue their disordered proliferation. They can then lead to the creation of blood vessels, acquire the ability to detach from the primary tumor, and penetrate the blood system, thus migrating to other “far-away” organs to establish secondary tumors (metastases).

In 2005, Dr. Yves St-Pierre and his team at the INRS-Institut Armand-Frappier, a university research centre in Laval, published the results of several years of research concerning the discovery of a protein involved in the formation of metastases. This protein, galectin-7, normally produced by skin cells when they are exposed to ultra-violet rays, is produced strongly by cancer cells and accelerates their propagation.

Currently, attempts are being made to establish how detecting the production of this protein by cancer cells could lead to establishing more precise prognoses and to developing new treatments to block the development of metastases. In the long term, one can foresee the possibility of a vaccine that would stimulate the immune system to recognize and eliminate specific cancer cells expressing galectin-7. One could also envisage another type of vaccine, made up of a sequence of nucleic acid (called antisense mRNA), to block the production of galectin-7 by the cancer cells.

Much more research is needed to find applications for this recent discovery of the role of galectin-7 in the development of cancer. Dr. St-Pierre and researchers in the four corners of the planet are dedicating their efforts towards this goal.

This article was produced with the collaboration of Dr. Yves St-Pierre, professor-researcher at the INRS-Institut Armand-Frappier.