You Were Always On My Mind

It is a well known fact regarding cancer, that an original tumor can spread to organs throughout the entire body of a patient. Breast cancer is no exception to this trend with cancer often spreading to vital organs of the body such as the lungs, and as medical records now show, to the brain. In humans, the two major genes responsible for breast cancers ability to spread have been identified in mice models as COX2 and HB-EGF. Until recently though, scientists were unsure how the cancer was commonly spreading to the brain.

The brain has a protective mechanism known as the blood-brain barrier, which is a tight network of capillaries and connective tissue that greatly restricts movement of any material between theblood flow of the rest of the body and the blood flow of the brain. This mechanism stops toxins, pathogens and most cancers entering the brain from the rest of the body. Despite this barrier, a recently discovered gene, ST6GALNAC5, is showing to play an important role in assisting breast cancer cells to enter brain tissue. ST6GALNAC5 creates enzymes that cause a chemical reaction on the outside of cancer cells causing them to become sticky. Combined with the action of the

previous two genes mentioned, mobile, sticky cancer cells can now be released into the bloodstream from the original breast cancer. When these sticky cells reach the blood-brain barrier, they are able to attach to the capillaries long enough for the cells to infiltrate into the organ itself where they will replicate and form a new tumor.

The good news out of this discovery is that researchers are confident that drugs can be developed to prevent the products of this gene causing the reaction responsible for breast cancers crossing to the brain. With breast cancer being the top killer of women globally, any advance in stopping even one part of these tumors spreading could save countless lives.

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Reference: http://au.news.yahoo.com/a/-/technology/5549112/genes-help-breast-cancer-spread-brain/, accessed 19/05/09