Characterization of novel extracellular vesicle-based biomarkers in pancreatic cancer
Pancreatic cancer is an incredibly aggressive and deadly cancer for which no general screening test is currently available. We seek to identify circulating extracellular vesicle (EV) protein biomarkers for use to diagnose and monitor pancreatic cancer. The expression of five potential markers (ALPPL2, Thrombospondin-2, Glypican-1, Integrin αVβ6, and DTNBP1) were studied in EVs isolated from conditioned media of pancreatic cancer cells and patient serum samples. Expression of these EV-associated proteins were measured by Western blotting and ExoView EV characterization assays. All five biomarkers were present in the EVs of both CA19-9 positive (SW1190) and negative (MIA PaCa-2) pancreatic cancer cells, indicating that the biomarkers are present on EVs secreted by the cancer cells regardless of CA19-9 levels. Amongst them, Glypican-1 and DTNBP1 were upregulated in CA19-9 negative cell lines. Out of the five, ALPPL2 and Integrin αVβ6 were also tested in a low CA19-9 patient sample. Both were detected at levels equivalent to that of cell line models. Studies are ongoing to further validate the utility of these EV proteins as potential biomarkers for pancreatic cancer patients who are negative for the CA19-9 marker.