Pancreatic cancer is the fourth leading cause of cancer death in the United States. Metastasis - the spreading of cancer from a primary site to distant organs is responsible for 90 percent of the deaths from pancreatic cancer. A fundamental event in metastasis is the migration of cancer cells. Accumulating evidence indicates that intracellular vesicle trafficking plays an important role in cell migration. In migrating cells, plasma membrane components and cell adhesion receptors such as integrins are transported by vesicles and exocytosed at the cell front or leading edge. However, it is not known what proteins drive polarized exocytosis and how exocytosis is modulated in cancer metastasis. Studies using model systems has demonstrated that pairing of SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins on vesicles (v-SNAREs) and SNARE proteins on target membrane (t-SNAREs) mediates intracellular vesicle fusion events including exocytosis. Our preliminary studies indicate that SNARE proteins are actively involved in cell migration. The hypothesis is that SNARE proteins mediate polarized exocytosis in migration of pancreatic cancer cells. Using cell-based assays, two Specific Aims will be pursued: 1) Define the function of endocytic v-SNAREs in migration of pancreatic cancer cells;2) Identify v-SNAREs that mediate the recycling of ?1 integrins to the cell surface. The long-term goal is to elucidate how the SNARE fusion machinery interacts with signal transduction cascades to regulate migration and metastasis of pancreatic cancer cells. Accomplishing the specific aims will deepen our understanding of polarized exocytosis in cell migration, and will likely provide potential targets for therapeutic strategies that target motility of pancreatic cancer cells.
Cancer metastasis is still not well understood at the molecular level, and current therapies are ineffective in preventing metastasis. Inhibiting the migration of cancer cells is a promising strategy to overcome metastasis. The proposed work will enhance our understanding of the most fundamental event in metastasis - migration of cancer cells.
