The cell specificity demonstrated by our cell-binding peptides indicates that they are recognizing distinct cell surface receptors that may be of clinical value. While it is true that we can utilize the cell-targeting peptides for delivery without knowing their cellular targets, receptor ID is a critical component of our research. Identifying the receptor will yield important biological information about the status of the cell surface and how the cell surface topography changes during a disease process.
Furthermore, identifying the cellular receptor is critical in terms of developing new diagnostic and targeting reagents. Antibodies can be generated to unique receptors and used as diagnostic and perhaps clinical reagents. Moreover, it will lead the way into developing non-peptidic targeting molecules. We are currently developing new chemical and molecular biology based technologies for the systematic isolation of the cellular target of the cell-homing peptides.
We have identified the receptor for one of the lung cancer targeting peptides as αvβ6. We have since shown that this integrin is up-regulated in lung cancer and is a marker for poor patient outcome. We are currently exploring the biological role that αvβ6 plays in lung cancer and exploiting this cell-surface biomarker for targeted delivery.