New stool biomarker proteins for pancreatic cancer by the proteome analysis

Background: The new biomarkers for early detection of pancreatic cancer (PC) is essential for improvement of prognosis. Recently, stool biomarker proteins using proteome analysis have been reported in biliary atresia. We hypothesized that the proteins derived from PC tissue were detected in stool of patients with PC. Stool samples have a grate advantage of clinical application in viewpoints of safety and convenience. Therefore, we explored new biomarker proteins for PC by the stool proteome analysis in this study.
Methods: Stool samples were collected from ten PC patients and ten healthy people before treatment and were analyzed by proteome analysis according to our previous study (Proteomes 2020;8:36). Candidate markers were filtered by the fold change (PC/healthy people) >2 and statistical significance (p<0.02). Their marker proteins were validated by immunohistochemistry staining (IHC) of PC tissues.
Results: Among the 2093 host-derived proteins detected in their stools, 50 proteins were filtered statistically. 12 proteins which were low expression in healthy people and associated with tumor biology were selected by database search. Additionally, we validated nine proteins: COL1A1, S1008A, ADH7, ENO1, SEC11A, SERPINB2, EIF6, CRISP3, and MDH1, in the PC tissue by IHC.
Conclusion: We identified candidate stool biomarkers associated with PC by the stool proteome analysis. We will perform a clinical pilot study.