The reason for this, according to Xu, is that we do not yet have a single drug therapy or a combination of therapies that reach the source of the problem.
To better understand the source, researchers looked to VEGF, or vascular endothelial growth factor, which plays a key role along the complex chain of interactions that occur as cancer develops and spreads. Most importantly, VEGF provides a potent chemical signal that stimulates new blood vessels. Tumor cells have a distinct need for oxygen and nutrients, and in this environment the nutrients in tumor cells trigger the secretion of the VEGF protein, which then leads to the formation of new blood vessels to fuel the tumor.
The dangerous cycle that feeds cancer cells with nutrients is referred to as angiogenesis. The Food and Drug Administration in recent years has approved several promising cancer drugs, called anti-angiogenesis therapies or VEGF inhibitors, which are designed to block the activity of VEGF protein once it has been secreted and released by the cells. Frequently, though, despite continuous therapy with anti-angiogenesis medications, some of the VEGF escapes, creating an environment for a relapse.
Xu's team wondered if the VEGF could be blocked earlier, before it was produced. Collaborators included post-doctoral fellow Liquan Yang, Ph.D., technical associate Sonali Mohanty, Arshad Rahman, Ph.D., associate professor of Pediatrics, Environmental Medicine, and Pharmacology and Physiology at URMC; and Glynis A. Scott, M.D., professor of Dermatology and Pathology and Laboratory Medicine at URMC.
Knowing that some involvement with cancer cells had been reported in the literature, they began a detailed investigation of G-protein-couple receptors (GPCRs). In the context of other diseases GPCRs constitute 40 percent of drug targets, making it an attractive option to control cancer if a link could be established.
|Contact: Leslie Orr|
University of Rochester Medical Center