Blood vessel structural cells can help limit tumor spread
Metastasis, a major cause of cancer-treatment failure and death in cancer patients, occurs when cells of a primary tumor detach and migrate through the bloodstream to grow elsewhere in the body. The complete mechanisms involved in metastasis are unclear, but it is known that blood vesselstabilizing cells, called pericytes, change their shape and partially detach from tumor vessels, suggesting that they allow the vessel to become leaky and cancer cells to escape. In a new study appearing online on February 9 in advance of print publication in the March issue of the Journal of Clinical Investigation, researcher Henrik Semb and colleagues at Lund University in Sweden report that pancreatic tumors in mice increase in size and spread to other organs when pericytes are unable to interact with blood vessel cells called endothelial cells. The authors found that the tumors of mice deficient in an adhesion protein known as NCAM (neural cell adhesion molecule) grow leaky blood vessels that allowed tumor cells to metastasize. In addition, mice that were genetically modified to be deficient in a pericyte recruitment protein called PDGF (platelet-derived growth factor), demonstrated metastases to the liver, kidney, and intestines, suggesting that loss of specific interactions between endothelial cells and pericytes are important in tumor cell spread. The authors suggest that NCAM limits tumor cell metastasis through its promotion of pericyte function, thus identifying a new mechanism for tumor cell migration.
TITLE: Pericytes limit tumor cell metastasis
Lund University, Lund, Sweden
Phone: 46462223159; Fax: 46462223600; E-mail: Henrik.Semb@med.lu.se<
Contact: Brooke Grindlinger
Journal of Clinical Investigation