It gives me a little pause when I reflect that healthy people produce up to 1,000 abnormal cells every day. Thankfully, our bodies have a tumor surveillance system that usually eradicates these wayward, cancer-prone cells.
A study released today by Lawrence Berkeley National Laboratory and published in the journal “Science Translational Medicine,” sheds more light on how this “innate immune system” works: Apparently, healthy breast tissue produces six or more proteins designed to attack cancer cells. A team led by Dr. Mina Bissell grew these in a 3-dimensional culture [more traditional lab cultures grow in two dimensions, like a sheet of paper, rather than like a cube]. The researchers found that the most potent weapon in the breast’s arsenal is a small protein called IL-25. Apparently IL-25 signals the tumor cells to self-destruct. The malignant cells die off because almost all tumor cells have an IL-25 receptor. In contrast, normal cells lack this receptor that fits the IL-25 protein.
It’s pretty amazing that, as disorganized and chaotic as breast cancer cells tend to be, they still have enough consistency to share this IL-25 protein receptor. It’s even more amazing that our bodies have evolved a defense to kill such cells, while leaving adjacent healthy cells untouched.
This is the first study to show that breast tissue has an innate, cancer-killing system. Researchers say this new knowledge may be exploited to create new drugs that use the IL-25 protein to target cancer cells. Of course, any drug is years, if not decades, away. But it’s a neat new wrinkle.