Bile-derived RNA N6-methyladenosine (m6A) methylation as a novel liquid biopsy biomarker for pancreatic cancer

Background Early detection of pancreatic cancer (PCA) remains a major challenge due to the lack of reliable biomarkers. Methods We investigated bile-derived N6-methyladenosine (m 6 A) modification as a diagnostic biomarker. Bile samples were obtained from patients with PCA (n = 7), biliary tract cancer (BTC; n = 35), and common bile duct (CBD) stones (n = 9). Global m6A levels were quantified using an ELISA-based colorimetric assay. Results Global m6A levels were markedly elevated in PCA bile (6.75 ± 1.25%) compared with BTC (1.25 ± 0.15%) and CBD controls (0.5 ± 0.1%) ( p < 0.001; Fig. 1). ROC analysis demonstrated excellent discrimination (AUC = 1.00, optimal cut-off = 1.1%). Consistent results were observed in pancreatic juice samples (AUC = 1.00, cut-off = 3.7%). Conclusions The results demonstrated distinct m⁶A elevation in bile from PCA patients (Fig. 1), supporting its translational potential as a minimally invasive biomarker. Validation in larger cohorts is warranted. These findings provide a proof-of-concept foundation for bile-based RNA methylation profiling in pancreatic cancer.