Suspecting that newly formed endothelial cells which line blood vessels in tumors may be different from those present in normal blood vessels, the investigators studied the endothelium isolated from both normal and tumor tissue of a colon cancer patient. The team used a panel of antibodies linked to beads, to isolate endothelial cells from the tissues. The team identified 46 genes that were overexpressed in tumor compared to normal endothelium, up to ten fold, and 33 genes that were expressed at significantly lower levels, providing some of the first scientific evidence that tumor endothelium behaves differently than normal endothelium. The researchers believe that endothelial cells, though not actually malignant themselves, create an environment that enables the tumor cells to thrive. As a result, they believe endothelial cells are promising therapeutic targets.
Cancer kills primarily when tumors grow so large that they interfere with organ and tissue function.
St. Croix likens tumor angiogenesis to grapes on a vine. If the drug does not reach a particular cell, the cell survives and replicates. Kenneth Kinzler, Ph.D., professor of oncology and director of this research, cautions, however, that such therapies are not close at hand. Their future research will focus on developing better therapy and diagnostic tests for cancer patients. They hope to develop genetic screening tests that would pinpoint these changes and help detect cancer at an early stage.