Dual Role of NRF2 in Pancreatic Precursor Lesions.

Pancreatic ductal adenocarcinoma (PDA) arises from distinct precursor lesions, primarily pancreatic intraepithelial neoplasia (PanIN) and intraductal papillary mucinous neoplasm (IPMN). Unlike PanIN, IPMN is a cystic lesion detectable by imaging, providing an opportunity for early intervention. However, the molecular determinants guiding the formation of PanIN versus IPMN remain poorly understood. In this study, we uncover a previously unrecognized role for nuclear factor erythroid 2-related factor 2 (NRF2), a master regulator of redox homeostasis, in dictating pancreatic precursor lesion fate. Although NRF2 is known to promote PanIN formation and sustain PDA, we found that active NRF2 levels are significantly lower in human IPMN compared with PanIN and PDA. Using a conditional NRF2 knockout mouse model, we demonstrate that NRF2 loss significantly increases IPMN-like cystic tumor formation in KRASG12D-mutant pancreatic epithelium, revealing an unexpected suppressive role of NRF2 in IPMN development. Mechanistically, NRF2 suppresses IPMN formation through redox-independent transcriptional repression of SAM pointed domain-containing Ets transcription factor and MUC6, key markers of IPMN. These findings establish NRF2 as a lesion-specific regulator of pancreatic tumorigenesis, providing new molecular insights into PDA progression and potential biomarkers for early detection and risk stratification.

Significance: This study reveals a context-dependent role of NRF2 in pancreatic tumorigenesis, promoting PanIN progression while suppressing IPMN formation. These findings provide new insights into early lesion heterogeneity and highlight NRF2 status as a potential biomarker for risk stratification in pancreatic cancer.