Tumor cell machinery susceptible to oncolytic viral replication

Tumor cell machinery susceptible to oncolytic viral replication refers to the collective molecular landscape and signaling defects in malignant cells that permit selective viral entry, genome replication, and assembly. In healthy cells, viral infection typically triggers the Type I interferon (IFN) response, leading to the expression of interferon-stimulated genes (ISGs) and the activation of Protein Kinase R (PKR), which halts protein synthesis to prevent viral spread (Xia et al., 2014, Molecular Therapy). However, many cancer cells acquire mutations in the JAK/STAT or IFN signaling pathways to evade immune surveillance, which simultaneously renders them unable to mount an effective antiviral defense. Additionally, constitutively active pathways such as Ras/MAPK can inhibit PKR, further facilitating the translation of viral mRNAs (Marcato et al., 2007, Clinical Cancer Research). Oncolytic viruses, such as the FDA-approved Talimogene laherparepvec (T-VEC), are engineered to exploit these specific vulnerabilities, ensuring that viral replication and subsequent cell lysis (oncolysis) occur preferentially in tumor cells. This process not only destroys the primary tumor but also releases tumor-associated antigens and danger signals, effectively turning the tumor into an in situ vaccine that stimulates a systemic anti-tumor T-cell response (Kaufman et al., 2015, Nature Reviews Drug Discovery).

Other names

Oncolytic virus susceptibility factorsDefective antiviral signaling in tumorsTumor-selective viral replication machineryPermissive tumor microenvironment for virotherapy

Oncolytic viruses selectively infect and replicate within tumor cells by exploiting defective antiviral defenses (e.g., impaired IFN signaling) and high metabolic activity, leading to direct oncolysis and the induction of a systemic anti-tumor immune response.