Scientists supported by the National Institute of Dental and Craniofacial Research (NIDCR), part of the National Institutes of Health, have added a key new piece to the puzzle of how tumor cells induce new blood vessels to form and fuel their abnormal growth, a well-known process called angiogenesis.
As published in this month?s issue of the journal Cancer Cell, the scientists found that in addition to the well-known strategy of secreting proteins to trigger angiogenesis, tumor cells also physically attach to a protein displayed on the surfaces of cells that line the walls of our blood vessels. This physical interaction, like a finger pushing a button, sends a signal within these cells to grow and sprout new capillaries.
The finding, while technical in nature, has potentially major implications for anti-angiogenic therapy, one of the hottest areas in cancer research. Dr. Cun-Yu Wang, a scientist at the University of Michigan and senior author on the paper, said the finding suggests a future anti-angiogenic strategy of blocking not only the secreted molecules but also the cell-to-cell contact.
Wang?s hunch also made good intuitive sense for another reason. The jagged1 protein bound in a hand-in-glove manner to a protein on the endothelial cells called notch. Other laboratories have shown that notch plays a key role during human development in forming blood vessels. Oddly, Wang noted, the possible role of notch in tumor angiogenesis has not been well studied.
Zeng added that because the research involved cells from head and neck tumors, the discovery could provide further insight into the uniquely invasive character of these cancers. He explained that cells in head and neck tumors tend to be mobile, shifting within the developing mass and possibly establishing tumor-to-endothelial cell contact to prompt angiogenesis.