Retroviruses and DNA: gene therapy for brain tumours

Gene therapy is a revolutionary new approach to the treatment of cancer, with potential use as an adjuvant and possibly even primary therapy for malignant brain tumours. Retroviral vector mediated transfer is the first mechanism for the introduction of foreign genes into target cells that is efficient, selective and safe enough to warrant the development of clinical therapeutic protocols in humans. Expression of the transduced herpes simplex thymidine kinase gene in glioma cells renders them highly sensitive to the toxic effects of ganciclovir. This gene has been transduced into central nervous system (CNS) tumours in vivo resulting in significant tumour cell death and in some cases, complete tumour eradication. Formidable technical obstacles still remain to be overcome before gene therapy can be generally accepted as a treatment modality. If the development of gene therapy on both a technological and commercial level continues at the current exponential rate then it is surely only a matter of time before these hurdles are overcome.