[Gene therapy for liver diseases--facts or fiction]

Molecular analyses have become an integral part of biomedical research as well as clinical medicine. The definition of the molecular and genetic basis of many human diseases has led to a better understanding of their pathogenesis and has in addition offered new perspectives for their diagnosis, treatment and prevention. Genetically, human diseases can be classified as hereditary monogenetic, acquired monogenetic and acquired complex genetic diseases. Based on this classification, gene therapy is based on four concepts: gene repair or substitution, block of gene expression (triple helix formation, sense strategy, ribozymes, small interfering (si) RNAs and gene augmentation as well as DNA vaccination. While recent developments are promising, various delivery, targeting and safety issues need to be addressed before gene therapy will enter clinical practice. In the future, gene therapy of liver diseases may become part of our patient management and complement existing therapeutic strategies.