Cancer cells tricked into suicide

It may be possible to beat ovarian cancer by tricking it into committing suicide, say UK scientists.

Cancer spreads because a gene which normally kills off cells is faulty in cancer cells. Scientists at Cancer Research UK say they have been able to get around this problem by inserting this “suicide” gene into cancer cells. The results were presented at Cancer Research UK’s Beatson International Cancer Conference in Glasgow. The gene that controls suicide in normal cells is called Smac. Cancer cells have a faulty Smac gene and carry on dividing and growing well beyond their allotted lifespan. Dr Iain McNeish and colleagues at the Cancer Research UK Molecular Oncology Unit in London used gene therapy techniques to mimic or restore the function of Smac. This turned the self-destruct mechanism back on and killed a large number of the cancer cells.Dr McNeish said: “This is a very exciting result because it implies that the action of Smac may be tumour specific.” As well as causing large numbers of the cells to commit suicide, the gene therapy made ovarian cancer cells more sensitive to chemotherapy drugs used to treat cancer. Previous studies have shown that Smac could enhance the effects of certain anti-cancer drugs. But this is the first study to show that the gene could be a potent way to tackle cancer on its own as well as a complement to other treatments. Gene therapy Dr McNeish said Smac was too large to be delivered as an anti-cancer drug and developing synthetic versions that could be absorbed by cancer cells would require a huge effort in the pharmaceutical world. “But sneaking the Smac gene into tumours using a virus could be an ideal way to overcome the problem. “Our results indicate that developing a gene therapy to increase the levels of Smac in cancer cells may be a promising avenue to follow,” he said. Professor Robert Souhami, Director of Clinical Research at Cancer Research UK, said: “There is a real need to find innovative new ways to tackle cancer. This work exploits our knowledge of genes involved in cancer and targets a very specific molecular mechanism. “There’s still work to do to find the best possible way of getting therapeutic genes into cancer cells, but over the coming decade we hope to see some exciting advances in this line of research.”(Source: Cancer Research UK: BBC News: June 2004)