Oncogenic KRAS drives type I IFN signaling, sensitizing pancreatic cancer cells to necroptosis

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers, projected to become the second leading cause of cancer-related death soon. Over 90% of PDAC cases are driven by activating KRAS mutations, which are fundamental to tumor initiation, progression, and therapeutic resistance. Current treatments often fall short due to the aggressive biology and lack of effective targets. This study explores a novel vulnerability by investigating how KRAS signaling influences programmed cell death pathways like necroptosis, offering a potential new therapeutic avenue.

Researchers utilized genetically engineered mouse models of PDAC to investigate the role of caspase-8 in tumor progression. They specifically deleted caspase-8 in cancer cells to observe its impact on cell death and lesion development. Additionally, they tested the therapeutic potential of pharmacologic caspase inhibition in aggressive PDAC mouse models and human patient-derived organoids. A pan-cancer transcriptomic analysis was also performed to correlate necroptosis gene expression with Ras pathway activity and IFN signatures across various tumor types.

The study found that oncogenic KRAS activates the cGAS-STING-TBK1 axis, which induces a type I interferon (IFN) response, thereby priming PDAC cells for necroptosis.

Cancer cell-specific deletion of caspase-8 was sufficient to trigger necroptotic cell death, effectively eliminating most pancreatic precursor lesions in genetically engineered mouse models. Mechanistically, KRAS-driven IFN signaling induced ISGF3-dependent expression of necroptosis-related interferon-stimulated genes (ISGs), including MLKL. This rendered PDAC cells selectively vulnerable to necroptosis upon caspase-8 inhibition. Therapeutically, pharmacologic caspase inhibition significantly reduced tumor burden in aggressive PDAC models and human patient-derived organoids. A pan-cancer transcriptomic analysis further linked necroptosis gene expression with Ras pathway activity and IFN signatures across multiple tumor types, suggesting broader applicability.