ABSTRACT
The concept of transfer of genetic information as a practical clinical tool arose from the gene cloning technology developed during the 1970s. The existence of an excellent animal model — the Watanabe heritable hyperlipidaemic rabbit — permitted a series of preclinical experiments to verify the principles of gene therapy in familial hypercholesterolaemia. The main problem facing the gene therapist is how to get new genes into every tumour cell. The insertion of a foreign marker gene into cells from a tumour biopsy and the replacement of the marked cells into the patient prior to treatment can provide a sensitive new indicator of minimal residual disease after chemotherapy. Tumour necrosis factor genes have been inserted into tumour-infiltrating lymphocytes from patients with melanoma, and given systemically. The downregulation of abnormal oncogene expression has been shown to revert the malignant phenotype in a variety of tumour lines in vitro.
