January 6, 2006
Three years ago, NIDCR grantees and colleagues identified nine genes with expression patterns that are markedly different in head and neck squamous cell carcinoma cells than in normal oral epithelial cells, a sign of their possible involvement in cancer. Among them was the headpin gene, short for "head and neck serpin." As the authors noted at the time, its possible role in head and neck cancer remained to be explored. Now, in the December 15, 2005 issue of the journal Cancer Research, the scientists provide an important characterization of the headpin protein. They show in laboratory and animal studies that headpin often localizes to the cell nucleus of oral epithelial cells, where the protein regulates the expression and secretion of various factors involved in the formation of new blood vessels, or angiogenesis. Interestingly, the scientists also found that headpin can be secreted from cells, where it inhibits blood-vessel forming endothelial cells from invading, migrating, or forming tubes, all of which are fundamental to angiogenesis. These data suggest head and neck squamous cell carcinomas must inactivate headpin to help spur the needed angiogenesis that fuels their abnormal growth. They also point to possible therapeutic targets to stop new blood vessel formation in head and neck squamous cell carcinoma and perhaps other cancers.