Suicide Gene Therapy Kills Bowel Cancer Cells
10 March 2008 - An innovative type of gene therapy has for the first time succeeded in making bowel cancer cells commit suicide. The treatment, known as GDEPT (Gene-Directed Enzyme Prodrug Therapy), combines a non-pathogenic virus and a harmless prodrug to produce a potent method of killing cancer, but not normal, cells.
Lead researcher Professor Caroline Springer, from The Institute’s Cancer Research UK Centre for Cancer Therapeutics, explains: “We have taken a virus and programmed it to produce a harmless protein in tumour cells. This protein can convert a harmless prodrug into a toxic drug. Thus, by combining two harmless entities we are able to produce a potent chemotherapeutic agent and we are able to restrict the effects of this to the tumour so healthy cells are not affected. The beauty of our approach is that the cancer cells are made to commit suicide by the virus and the activated drug – the two work in tandem.” Another benefit of the therapy is that it does not just kill only the cancer cells infected by the virus. “We also see a significant ‘bystander effect’,” added Professor Springer. “This means the tumour cells are killed by the activated drug even if the virus does not infect them, amplifying the tumour killing potential of our approach.”
This is the first time such a therapy has proved successful at killing bowel cancer cells, albeit only in the laboratory. In principle, this suicide gene therapy can be used for a wide range of different tumours. The Institute and Cancer Research UK are supporting the development of this therapy, and hope to take it into clinical trials. The first clinical trial is planned to be in head and neck cancer so that biopsies can easily be taken to assess the effectiveness of therapy.
Professor Caroline Springer leads the Gene and Oncogene Targeting Team in The Institute's Section of Cancer Research UK Centre for Cancer Therapeutics