While studying the mechanics of blood clots, researchers at the University of Oklahoma discovered a new enzyme that not only affects the blood, but seems to play a primary role in how cancer tumors expand and spread throughout the body.

The research appeared in the latest issue of the journal Blood available in Washington on Thursday.

The research team first discovered the enzyme called FAP in plasma. After studying the biochemical makeup of the protein and identifying the gene that controlled its function, they began to search gene sequencing databases worldwide to find what it was.

They didn't find the enzyme listed for blood, but got a match with a virtually identical protein known to cause cell growth in tissue, including in cancer. With the discovery that the protein also exists in blood, scientists have a new avenue to study the spread of cancer.

The main function of the original FAP protein that was known to exist in tissue is to accelerate tissue growth and expand cells during fetal development, the healing of severe wounds and during growth of selected cancers such as breast, lung, pancreatic and colon.

Other than in these situations, the original form of FAP is not normally expressed in tissues at all. When it does appear, the protein helps activated fibroblasts, which growing cancer cells are able to recruit and stimulate to multiply within the malignancy itself. This creates space and the framework on which cancer cells attach, divide and eventually spread.

If FAP could be inhibited, then cancer growth could be slowed or halted, which in combination with chemotherapy or radiation might offer the potential to actually cure the malignancy, the researchers believe.

(Xinhua News Agency December 5, 2008)