Abstract
As of summer 2000, more than 400 protocols developed for human gene therapy have been reported, and there have been recent successful applications in some diseases such as arteriosclerosis obliterance, immunodeficiency X-1 (SCID-X1) and hemophilia B. However, complications have also occurred. Successful gene therapy is dependent on the development of an effective gene delivery system. One approach is development of chimeric vector systems that combinine at least two different vector systems. However, a perfect vector system has not yet been constructed. Difficulties of in vivo gene transfer appear to result from resistance of living cells to invasion by foreign materials and from interference of cellular functions. We should reevaluate what barriers in tissues affect in vivo gene transfection and how to solve these problems for gene therapy. Moreover, in Japan, there should be more extensive preparation of social systems to promote clinical trials based on basic research.
