Cell's Sugary Coating Zaps Cancer

Release Date:
4/2/2003
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Heparin is an inexpensive medicine that doctors use to "thin" blood and stop it from clotting. The medicine is widely prescribed to treat dozens of health conditions in which blood clotting can be especially dangerous, such as stroke and many heart disorders. Heparin and other complex sugar molecules like it cloak the surfaces of nearly all the cells in our bodies, as well as the surfaces of cancer cells. Recently, scientists have recognized the potential importance of a cell's sugar "coat" in the development of disease.

Researchers studying the biochemistry of heparin and other natural sugar molecules may have unearthed a potential new use for heparin: treating cancer. To examine the possible role of heparin in cancer, Dr. Ram Sasisekharan of the Massachusetts Institute of Technology injected an enzyme called heparinase into mice with tumors. Heparinase enzymes cut up complex sugars, generating molecules of heparin. These enzymes exist in several forms, each of which cuts complex sugar molecules in different places and generates different “trimmed” forms of heparin. Dr. Sasisekharan found that one particular heparinase treatment slowed the growth of skin, lung, and prostate tumors in the mice. Surprisingly, however, another member of this heparinase enzyme family actually sped tumor growth in mice. Dr. Sasisekharan suspects that the sugary molecules interact with cancer-controlling proteins circulating in the blood and on the surfaces of other cells, and that slightly different forms of heparin can have very different effects on cell growth and cancer.

Further studies are needed to sort out the cancer-slowing and cancer-promoting properties of heparin. If the findings in experimental mice can be repeated in people, the appropriate form of heparin could potentially be put to use quickly as a cancer treatment, since the medicine has already been demonstrated to be safe for human use and has been approved by the Food and Drug Administration. The results also illuminate a basic mechanism that may contribute to the development of diseases like cancer.