Cancer gene therapy often uses strategy of:
Cancer gene therapy predominantly adopts tumoricidal strategy rather than restoration tumor suppressor because cancer genome carries multiple gain-of-function oncogenes KRAS MYC aneuploidy heterogeneity complicating simple addition. Methods eliminate malignant clone through introduction genes triggering death or immune recruitment. Oncolytic adenoviruses engineered deletion E1B 55 kDa protein normally inactivating p53 replicate selectively p53-deficient cancers lysing cells via viral burst releasing PAMPs tumor antigens danger signals ATP calreticulin HMGB1 driving immunogenic cell death. Suicide enzyme systems HSV TK ganciclovir produce toxic dGTP analog inducing apoptosis. Cytokine transgenes GM-CSF IL-12 IFN-alpha secreted transduced tumor cells recruit dendritic cells cytotoxic T lymphocytes cross-presenting released antigens epitope spreading generating systemic immunity targeting distant metastases abscopal effect. CAR-T gene editing deleting TRAC preventing graft-versus-host PDCD1 enhancing persistence exemplifies combined transfer editing enhancing tumoricidal efficacy overcoming resistance inherent monogenic correction approaches limited single gene restoration. This mechanistic insight guides vector optimization, dosing strategies, and clinical safety monitoring essential for translational development and regulatory evaluation.
Ref: Nature Reviews Cancer Gene Therapy Oncolytic Mechanisms 2021; NCI Cancer Gene Therapy Targeted Killing; Molecular Therapy Oncolytic Viruses 2021.