[Gene therapy approaches to gastrointestinal tumors]

Gene therapy offers an elegant alternative to toxic chemotherapy regimens, mostly without severe side effects. Gene therapy for cancer was one of the first applications. Following the enthusiasm in the early 1990 s, a more rationale view is preferred today. This general review looks at the tools of gene therapy and their principle elements (vector, promoter, targeting, therapeutic genes). The principles of gene therapy such as gene-directed enzyme prodrug therapy (GDEPT) and gene-directed tumor vaccination are explained. Furthermore, published protocols and clinical studies in gastrointestinal oncology are reviewed. Finally, an outlook is given on the latest developments, some of them going beyond the realm of conventional gene therapy.