Tumor cells with defective antiviral signaling pathways (Interferon-Janus kinase-Signal transducer and activator of transcription-Protein kinase R) (IFN-JAK-STAT-PKR defective tumor cells)

Tumor cells with defective antiviral/IFN–JAK-STAT/PKR pathways refers to a physiological state common in many cancers where the innate immune response is compromised. In normal cells, Type I Interferons (IFNs) bind to receptors, activating the JAK-STAT signaling cascade to induce an antiviral state, often mediated by Protein Kinase R (PKR), which inhibits protein synthesis to stop viral spread (Stojdl et al., 2000, Nature Medicine). Many tumors acquire defects in these pathways—such as loss of IFN receptors, mutations in JAK1/2 or STAT1, or downregulation of PKR—to avoid growth inhibition and immune surveillance (Kaufman et al., 2015, Nature Reviews Cancer). This deficiency is exploited by oncolytic viruses, which are designed to replicate selectively in these defenseless cells while being neutralized by the intact antiviral machinery of healthy cells (Lichty et al., 2014, Nature Reviews Cancer). Consequently, this cellular phenotype serves as a functional target for virotherapy, leading to selective tumor cell lysis and the subsequent release of tumor-associated antigens to stimulate a systemic immune response (Zamarin & Wolchok, 2014, Science Translational Medicine). This strategy effectively turns a tumor's evolutionary advantage into a therapeutic vulnerability, as seen with the clinical development of agents like Talimogene laherparepvec (Kaufman et al., 2015, Nature Reviews Cancer).

Other names

IFN-deficient cancer cellsPKR-deficient tumor cellsAntiviral-deficient tumor phenotypeJAK-STAT defective cancerInterferon-defective tumor cells

Selective viral replication and oncolysis within cells lacking functional Type I Interferon and PKR-mediated antiviral defenses.