Cancer is still a major cause of death in humans. The novel approaches to tumor treatment are targeted therapies that increased hope for improving the treatment of therapy resistant tumors. By relying on new human understanding of the molecular pathogenesis of cancer we can then development of targeted novel drugs such as Nanobodies and monoclonal antibodies, small molecule inhibitors, mimetic, antisense, small interference RNAbased strategies and design and application of oncolytic virotherapy approaches. Tumor-specific killer proteins could derive from both human and animal viruses are such as E4ORF4 and VP3 (apoptin), E1A, viral protein R (VpR), Brevinin-2R, Large T protein, TTV apoptosis-inducing protein (TAIP). Chicken anemia virus (CAV) was isolated in 1979 by Yuasa (Japan), in commercial poultry. CAV is a resistant and ubiquitous virus belongs to the Gyrovirus genus, Circoviridae family and has a circular single strand DNA. It infects and cause disease in young chickens and immunosuppression in all birds. Hematopoietic stem cells in the chicken bone marrow and T-cell precursors in the thymus are the major targets for this virus infection. Apoptin (or VP3) is a small protein (14 kDa) encoded by VP3 gene of CAV. It has attracted great attention because of its tumor-selective toxicity potency means induces of cell death specifically in human transformed or tumor cells. In normal cells, Apoptin remains in the cytoplasm whereas in cancerous cells, it translocates into the nucleus and kills the cell. By nuclear localization of Apoptin, it mediate apoptosis and this mechanism is p53-independent and cannot be blocked by Bcl-2 .This article aims to present a current applications and novel progresses of using apoptin as tumor-specific killer agent and will provide an insight into the possible mechanism of action. Finally we will suggest a new direction for the therapeutic use of viruses and viral proteins for treatment of different kinds of Cancers.
ranjbar S, mosavi nasab S, ahmadi N, basati G. Promising therapeutic approaches for Cancer lying on unique features of Apoptin protein from chicken anemia virus (CAV) . J. Ilam Uni. Med. Sci. 2013; 20 (5) :158-167 URL: http://sjimu.medilam.ac.ir/article-1-939-en.html