Advances in Cancer Gene Therapy

The potential effectiveness of gene therapy in cancer treatment is promised not only by its precise targeting of the mechanisms of the disease, but also by its genetic approaches that are based on rapidly advancing molecular biotechnology. Diverse strategies and innovative approaches to cancer gene therapy have been developed. Despite the great potential and rapid advances in this technology, the development of cancer gene therapy is at a very early stage. This chapter presents an overview of the current state of this field, for understanding the prospects of cancer gene therapy. Nonviral gene delivery systems are one of the current approaches to gene transfer. There is a variety of effective nonviral techniques for transfection of DNA into mammalian cells in vitro, such as calcium-phosphate precipitation, polycation-mediated transfection, protoplast fusion, electroporation, microinjection, and liposome- or ligand-mediated gene transfer. The last two methods have the greatest potential to be further developed for the purpose of in vivo gene transfer. Moreover, direct injection of naked DNA into susceptible tissues is a unique approach for nonviral in vivo gene transfer. Other than nonviral approach there are also other approaches such as recombinant virus-mediated gene transfer. For the purpose of cancer gene therapy, ideal viral vectors are considered that have the ability to target gene delivery, have a large gene-carrying capacity, allow highly efficient gene transfer, allow controllable or tissue-specific gene expression, have high therapeutic potentials, and have low immunogenicity and cytotoxicity. The explosive advances in research of gene regulation of cells and molecular mechanisms of diseases have aided in the design of drugs that target genetic sequences through specific recognition of and by hydrogen bonding among complementary bases. Along the pathway for genetic information, flow from DNA to protein, several approaches have been developed to modulate gene expression and regulation.