Novel angiogenesis mechanism

Tumor cells can trigger angiogenesis by a process involving physical contact with neighboring endothelial cells, scientists report in this month's issue of Cancer Cell. This is the first time, according to the paper, that such a mechanism has been described involving the Notch pathway, which is known to play key roles in embryonic vascular development and angiogenesis, but whose participation in tumor angiogenesis has been unclear.

There are several ways by which a tumor might stimulate angiogenesis, said coauthor Jan Kitajewski, from Columbia University in New York, including the well-documented paracrine mechanism and some emerging contact-dependent mechanisms. "Here Notch seems to act as a proangiogenic factor in head and neck tumors," he told The Scientist, "and it probably does so in other tumors."

The team, led by Cun-Yu Wang from the University of Michigan, Ann Arbor, conducted a microarray analysis of head and neck squamous cell carcinoma cells. "We discovered ...