Review article: gene therapy in gastroenterology and hepatology.

Gene therapy for diseases of the gastrointestinal tract is an exciting prospect because of the fundamental cure that is potentially available. The gastrointestinal system, and especially the liver, is an area that will be central to the development of gene therapy. Techniques for gene replacement include homologous recombination and gene augmentation. For the treatment of cancer antisense strategy, pro-drug activation systems and gene immunotherapy are being investigated. Gene-carrying vectors divide into viral- and non-viral-based vectors, each with advantages and limitations. The accurate delivery of these vectors to sufficient numbers of target cells in vivo is still a major barrier to clinical use. Diseases that may be helped by gene therapy include: gastrointestinal malignancies, viral hepatitis, the haemophilias, hypercholesterolaemia, alpha 1-antitrypsin deficiency, and metabolic diseases of the liver and cystic fibrosis. In this review we will outline the principles of gene therapy, delivery vectors under investigation, diseases that may benefit from this technology and some of the remaining problems to be overcome.