Autoantibody signature in human ductal pancreatic adenocarcinoma.

To identify ductal pancreatic adenocarcinoma (PDA) associated antigens, proteins from PDA cell line (CF-PAC-1) were separated by two-dimensional electrophoresis (2-DE) and IgG reactivity of 30 PDA patient, 21 healthy donor, 30 non-PDA patient and 15 chronic pancreatitis (PC) sera was tested by Western blot analysis. Proteins recognized by PDA sera revealed by mass spectrometry were metabolic enzymes (a-enolase, triosephosphateisomerase 1, phosphoglycerate mutase 1, Ras-related nuclear protein, aldehyde dehydrogenase, glucose-6-phosphate-1-dehydrogenase, elongation Factor TU and isocitrate dehydrogenase), cytoskeletal proteins (keratin 10, cofilin , and transgelin) and an hypothetical protein. With the exception of a-enolase, all these proteins were recognized by PDA sera (from 17 to 30%), but not from healthy subject, non-PDA and PC patient sera. Of six a-enolase isoforms, only the two more acidic ones were recognized with high frequency (50%) by PDA sera and with low frequency (7%) by PC sera, whereas the remaining were recognized with low frequency (5-10%) by healthy subject and non-PDA sera and with intermediate frequency (20-40%) by PC sera...................