Luteolin Triggers Pyroptosis in Pancreatic Ductal Adenocarcinoma by Inhibiting Mitochondrial Fission through the RAS/ERK/DRP1 Pathway.

Pancreatic ductal adenocarcinoma (PDAC) is among the most lethal malignancies and lacks effective therapies. Luteolin, a dietary flavonoid with broad antitumor activity, has shown anti-PDAC potential, yet whether it acts through RAS/ERK/DRP1-dependent mitochondrial fission and pyroptosis remains unclear. Human PDAC cells were treated with luteolin to evaluate its effects on malignant phenotypes, including proliferation, apoptosis, migration, and invasion. Mitochondrial function and morphology were assessed by measuring mitochondrial membrane potential, mitochondrial ROS production, and mitochondrial network remodeling. Pyroptosis was evaluated by measuring NLRP3 inflammasome activation, pyroptosis-related proteins, and cell injury-associated indicators. Mechanistically, MCC950, RAS overexpression, DRP1 overexpression, EGF stimulation, and Mdivi-1 treatment were used to determine the involvement of NLRP3 inflammasome activation and the RAS/ERK/DRP1-mediated mitochondrial fission pathway. A subcutaneous xenograft model was further established to validate the antitumor effect of luteolin in vivo. Luteolin significantly inhibited the growth, migration, and invasion of PANC-1 and MIA PaCa-2 cells, while increasing apoptosis. It induced mitochondrial membrane potential loss, enhanced mitochondrial ROS production, reduced mitochondrial number, suppressed mitochondrial fission, and promoted mitochondrial network remodeling. Luteolin also upregulated NLRP3 inflammasome- and pyroptosis-related proteins, and these effects were partially reversed by MCC950. Mechanistically, luteolin inhibited the RAS/ERK/DRP1 pathway, whereas RAS or DRP1 overexpression partially attenuated luteolin-induced mitochondrial dysfunction and pyroptosis-related changes. Mdivi-1 produced effects similar to those of luteolin, supporting the involvement of mitochondrial fission disruption. In vivo, luteolin inhibited tumor growth without obvious systemic toxicity. These findings indicate that luteolin suppresses PDAC progression by inhibiting RAS/ERK-dependent, DRP1-mediated mitochondrial fission, thereby inducing mitochondrial dysfunction and triggering pyroptosis.