Saturday, February 5, 2011
That's How Breast Cancer Cells Roll
When cancer metastasizes, cells break off from the primary tumor, travel through the lymphatic or circulatory system, and then invade other tissue. Now researchers have found a protein that allows breast cancer cells to roll along blood vessel walls—a key step in the metastatic process (Anal. Chem., DOI: 10.1021/ac102901e).
Cancer cells take a page from white blood cells' playbook when it comes to tissue invasion. When responding to an injury, leukocytes cling loosely to the cells lining a blood vessel wall and then, propelled by the shear force of the rushing fluid, roll along it like Velcro-covered soccer balls. They continue until they can attach tightly enough to worm their way between the wall's cells and into the surrounding tissue. To perform these cellular acrobatics, two proteins must interact: selectins, which protrude from vessel wall cells, and their ligands, which leukocytes and circulating tumor cells express on their surfaces.