Gene and Viral Therapy

Abstract

The aim of gene therapy is to treat cancer by the introduction of genes that will sensitize tumour cells to other therapies, replace a mutated gene with a wild‐type copy, or activate an antitumour host immune response. Viruses can be used as vectors for carrying therapeutic transgenes, as well as being oncolytic in their own right. Using viruses to treat tumours derives from the inherent ability of a replicating virus to eventually destroy its host cell. Oncolytic viruses are tumour specific, causing lysis of tumour cells and not normal cells. There are viruses that are naturally tumour specific and viruses that have been engineered to become tumour specific. More recently, there has been increasing interest in the development of non‐viral vectors as gene therapy carriers. The benefits of using non‐viral vectors is that they are less likely to elicit an unwanted immune response, there is no risk of recombination, and they are easier to produce on a large scale. There are two main types of non‐viral gene delivery method—physical and via a chemical carrier. Both viral and non‐viral vectors have entered human phase I and II clinical trials in patients with a variety of solid tumour malignancies.