Luteolin induces pyroptosis in pancreatic ductal adenocarcinoma by inhibiting the RAS/ERK/DRP1 pathway to trigger mitochondrial dysfunction and activate the NLRP3 inflammasome

Aims: This study aimed to explore the anticancer mechanism by which luteolin induces mitochondrial dysfunction and triggers pyroptosis in pancreatic ductal adenocarcinoma cells. Methods: Pancreatic ductal adenocarcinoma (PDAC) cell lines were treated with luteolin in vitro. A series of assays, including CCK-8, EdU, colony formation, wound healing, transwell migration and invasion, flow cytometry, JC-1, MitoSOX, and MitoTracker staining, were performed to assess cell proliferation, migration, invasion, apoptosis, mitochondrial function, and morphology. Western blotting was used to detect proteins related to mitochondrial dynamics and pyroptosis. The involvement of the RAS/ERK/DRP1 pathway was evaluated through DRP1 overexpression and treatment with Mdivi-1 (a mitochondrial fission inhibitor). In vivo, a subcutaneous tumor model was established to evaluate tumor growth and the expression of key markers via immunohistochemistry (IHC). Results: Luteolin inhibited the proliferation, migration, and invasion of PANC-1 and MIA PaCa cells while inducing their pyroptosis. It disrupted the mitochondrial membrane potential and elevated mitochondrial ROS levels. Mitochondrial morphology analysis revealed a reduction in mitochondrial number and fission, along with an increase in the mitochondrial area and network formation. Luteolin downregulated the RAS/ERK/DRP1 signalling pathway and upregulated components of the NLRP3 inflammasome. DRP1 overexpression reversed these effects, whereas Mdivi-1 mimicked them. In vivo, luteolin suppressed tumor growth, reduced Ki67 expression, activated pyroptosis markers (NLRP3 and GSDMD-N), and inhibited the expression of pDRP1 and pERK. Conclusion : Luteolin induces mitochondrial dysfunction and pyroptosis in pancreatic ductal adenocarcinoma cells by downregulating the RAS/ERK/DRP1 pathway, leading to mitochondrial ROS accumulation and NLRP3 inflammasome activation.