[Prospects for molecular research in urological oncology: gene therapy]

The recent great advances in genetic engineering are now making possible the identification and isolation of the trigger genes of many hereditary illnesses, and the clarification of the relevant molecular mechanisms. The idea that if the genetic abnormalities responsible for illness could be established at a DNA level, treatment at the genetic level repairing damaged genes or supplying absent ones would also be possible was the incentive for the recent boom in gene therapy. Clinical research into gene therapy began in 1990 and currently over 3,000 patient cases are being studied. Some 70% of these are cancer patients. This is not simply because such patients are relatively numerous, but is also a sign of the wish, held earnestly by many researchers and clinicians as well as cancer patients and their families, to at last overcome this intractable disease. Gene therapy, so far conducted mainly in the United States, has hitherto not lived up to initial expectations in its concrete results. The reason for this results mainly in technical factors, such as the rate of success in implanting genes into target cells, the rate of successful expression of the implanted genes, and the successful achievement of specific expression at the target site. Gene therapy in the form of clinical research into renal cancer and lung cancer is now under way in Japan. It is too early at this stage to evaluate this work, but the present paper takes this opportunity to give an outline of gene therapy, and to examine its current state, future prospects and problem areas with particular reference to cancer.