Arachidonic acid induces pyroptosis via a non-autophagic function of mitophagy and enhances immunotherapy in a PDAC model

Pancreatic ductal adenocarcinoma (PDAC) presents a therapeutic hurdle owing to its immunotherapy resistance and limited treatment options. Pyroptosis, a lytic inflammatory cell death pathway, holds promise for reversing immunosuppression in "cold" tumors, yet tumor-specific induction strategies remain unclear. Here, we employ a contrastive learning graph neural network to identify arachidonic acid (AA), an endogenous ω-6 polyunsaturated fatty acid, as a pan-cancer pyroptosis inducer operating through irreversible mitochondrial permeability transition inducing Caspase 3/GSDME activation. Crucially, a repurposed mitophagy machinery for non-autophagic functional scaffolding of Caspase 3/GSDME on autophagosomal membranes enables rapid pyroptotic execution. Pharmacological accumulation of autophagosomes amplifies AA-induced pyroptosis in PDAC organoids and patient-derived xenografts. Furthermore, AA-triggered pyroptosis, remodels immunosuppressive tumor microenvironments, boosting cytotoxic T cell infiltration and synergizing with anti-PD-1 therapy in immunocompetent models. Thus, our findings position AA as a candidate dual-function agent for pyroptosis-immune synergy, while autophagosome manipulation emerges as a strategy to potentiating strategy.