Abstract: Objective To investigate the expression levels and clinical significance of the CD59 blood type gene in pancreatic adenocarcinoma (PAAD) using bioinformatics techniques. Methods CD59 mRNA and protein expression in PAAD were analyzed via GEPIA, UALCAN, and HPA databases. The TIMER database was utilized to examine the correlation between CD59 in PAAD and immune cell infiltration, UALCAN database to investigate how CD59 in PAAD affected signaling pathways influencing PAAD progression, STRING database to explore the interaction between CD59 expression and upstream/downstream proteins, and Single-factor Cox and multi-factor Cox regression results to assess the association between CD59 blood type and PAAD prognosis. Results mRNA and protein expression levels of CD59 were significantly elevated in PAAD compared to adjacent tissues (P<0.05). Patients with high CD59 expression had a poorer prognosis than those with low CD59 expression in PAAD. The expression of CD59 in PAAD correlated positively with CD8+ T cells, macrophages, neutrophils, and dendritic cells (correlation coefficient>0, P<0.05). Single-factor and multi-factor Cox regression analyses established high CD59 expression as a risk factor for PAAD prognosis. KEGG enrichment analysis revealed a predominant role of the complement and coagulation cascades, while GO enrichment analysis indicated the dominance of regulatory signaling pathways in protein processing. Conclusion The CD59 blood type gene exhibits higher expression in PAAD and correlation with its occurrence, development, and adverse prognosis, suggesting its potential as a diagnostic/prognostic indicator and therapeutic target for PAAD.

Key words: Pancreatic cancer, Bioinformatics, CD59 gene, Database