An Overview on Oncolytic Viruses as Cancer Therapy

The current regimen of cancer therapy (chemotherapy and radiotherapy) suffers with disadvantages such as narrow therapeutic index that further facilitate tumor evolves drug resistance and severe side-effects. Oncolytic viruses are therapeutically useful anticancer viruses that will selectively infect and damage cancerous tissues without causing harm to the normal tissues. Many naturally occurring Oncolytic viruses have a preferential tropism to tumor or associated endothelial cells and others are genetically engineered to change their cellular or organ tropism toward cancer. Antitumor effect of Oncolytic viruses is either by locale cell death or by initiation of the systemic immune response against tumor. Oncolytic Adenovirus, Herpes Simplex Virus, Newcastle Disease Virus, and Reoviruse are representative of Oncolytic viruses that have potential to lysis tumor. The effects of the host immune response on the efficacy of Oncolytic viruses are complex. But, using of carrier cells as delivery vehicles could hide the viral antigen from antibodies and complements. Oncolytic viruses have been combined with many cancer therapies to increase response against cancer. Since many forms of canine or feline neoplasms resemble to humane counterpart. So, oncologists believe that Oncolytic virotherapy could soon be a reality in veterinary medicine.