Basics of cancer gene therapy

Abstract

Gene therapy is a rapidly evolving concept for the therapy of different forms of cancer. A number of phase-I clinical trials have recently been initiated world wide. This review discusses the technical concepts underlying the protocols currently coming into clinics. Two tools essentially constitute such concepts, the vector for efficient transfer and expression of the transgene in the cancer cell, and the therapeutic gene. The most advanced vectors ready for clinical use are the retrovirus- and adenovirus-derived vectors. The application of a broad spectrum of therapeutic genes can be classified into gene replacement of replace e.g. mutated tumor suppressor genes, gene addition to increase immunogenicity by cytokine genes or introduce prodrug genes for suicide induction and, thirdly, targeted affection of gene expression by antisense oligonucleotides or expression of ribozymes e.g. directed against oncogene sequences. Cancer gene therapy holds great promise to become an important addition to the multimodality in the therapy of some forms of cancer.