Researchers have found that an enzyme associated with inflammation may be effective in suppressing tumor and ulcer growth in colitis-associated cancer—a form of colorectal cancer. This type of cancer is driven by chronic inflammation, and while some inflammation is a healthy response to damaged tissue or pathogens, when left unregulated it can cause malignant cells to form in the tissue that could potentially become cancer. The enzyme is called matrix-metalloproteinase or MMP9, and has been found to suppress tumor growth within colitis-associated cancer caused by chronic inflammation.
While the activity of MMP9 is normally undetectable in healthy adult tissues, it is seen as highly active in a number of different inflammatory states. It can be found most active within the epithelial cells that make up the lining of the gastrointestinal tract, which is the origin of most colorectal cancers. To determine whether the MMP9 found in epithelial cells function defensively in the instance of colitis-associated cancer, researchers studied its role in both humans and mice.
The results showed that mice with higher activity of MMP9 in the epithelial cells had fewer tumors, as well as an increase in apoptosis—cell death that targets cells that are harmful or unneeded. In humans, the results showed a decrease in the speed of cell formation that contributes to cancer growth, as well as less DNA damage. Researchers also found that the MMP9 found in epithelial cells was able to suppress tumors by activating a specific pathway which increased apoptosis, initiated the end of cell cycles, and kept DNA damage lower.