Identification of Metabolic Characteristic-Pancreatic Ductal Adenocarcinoma Associations Using Mendelian Randomization and Metabolomics.

Background: Metabolic reprogramming is increasingly recognized as a crucial factor influencing the development, progression, and prognosis of pancreatic ductal adenocarcinoma (PDAC). Despite this, the potential association of specific metabolic characteristics and PDAC remains ambiguous due to the variability introduced by individual patient differences. In this study, we aimed to find out metabolic pathways that may be associated with the overall survival (OS) of PDAC patients.

Methods: We utilized Mendelian randomization (MR) to assess the associations between 1400 metabolites and metabolite ratios and PDAC. We performed functional annotation and pathway enrichment analysis on both significant metabolites and the shared proteins corresponding to the significant metabolite ratios. Additionally, we analyzed peripheral blood metabolites from 32 PDAC patients to correlate metabolites with clinicopathological features and OS. Functional enrichment analysis was also conducted on the significant metabolites.

Results: Our MR analysis revealed 55 metabolites/metabolite ratios associated with PDAC. Among the top 20 enriched metabolic pathways involving proteins related to significant metabolite ratios, seven were associated with amino acid metabolism, three with carbohydrate metabolism, and two with lipid metabolism. Serum metabolomics of PDAC patients highlighted significant upregulation in pathways related to primary bile acid biosynthesis, as well as taurine and hypotaurine metabolism, which correlated negatively with OS. Conversely, pathways involved in arginine biosynthesis, arginine and proline metabolism, and aminoacyl-tRNA biosynthesis were notably downregulated and positively associated with OS. Both upregulated and downregulated differential metabolites were notably enriched in the pyrimidine metabolism pathway, which was linked to poorer OS. These associations were corroborated by MR analysis.

Conclusion: The study provides valuable insights into the metabolic characteristics associated with PDAC, offering a reference point for improving diagnosis and treatment for PDAC.