apoptin

Apoptin is a small (~13.6–14 kDa) proline-rich, intrinsically disordered protein encoded by the VP3 gene of the chicken anemia virus, with potent and selective apoptosis-inducing capability in cancer cells. Unlike in normal cells where it remains cytoplasmic and inert, in transformed or malignant cells, apoptin translocates to the nucleus and triggers apoptosis through a p53-independent, mitochondrial-mediated, caspase-3-dependent pathway, and sometimes via mitotic catastrophe. Key to its selectivity is phosphorylation at threonine-108, regulated by tumor-specific kinases (such as PKCβ or CDK2), which ensures nuclear accumulation in cancer cells and inactivation in healthy cells. Apoptin does not rely on the status of p53, Bcl-2, or BCR-ABL1 expression and may induce apoptosis through the p73 pathway when p53 is inactive. It has been evaluated as a gene therapy agent in preclinical models using viral vectors, plasmids, fusion proteins, and polymeric nanoparticles, showing tumor cell selectivity and synergy with chemotherapy and radiotherapy. While promising, its tumor specificity has been debated, and clinical development remains preclinical or at very early clinical stages[1][2][3][4][6].

Other names

chicken anemia virus VP3 proteinCAV VP3tumour-selective apoptosis-inducing protein