Prolonged KRAS-MAPK Inhibition Induces Interferon-mediated Epithelial-to-Mesenchymal Transition and Reveals Therapeutic Opportunities

However, analyses of PDAC samples from patients treated with KRASG12C inhibitors have revealed secondary mutations restoring MAPK signaling and promoting epithelial-to-mesenchymal transition (EMT) as key mechanisms of acquired resistance. Here, we show that human PDAC specimens and patient-derived cell lines treated with the ERK inhibitor ulixertinib display upregulation of EMT-associated and inflammatory gene programs, particularly those linked to the interferon response.

Using the GeneRep-nSCORE computational framework to reconstruct and rank regulatory networks enriched in ERKi and KRASi-resistant PDAC cells, we identified TRIM22, an interferon-inducible E3 ubiquitin ligase, as a critical mediator of EMT and treatment resistance. Mechanistically, TRIM22 promotes proteasomal degradation of IκBα, leading to activation of NF-κB signaling, a known driver of EMT. Notably, we identify TACSTD2, encoding Trophoblast Cell Surface Antigen 2 (TROP2), as an NF-κB target gene upregulated following EMT.