London, Nov. 10: British scientists are on the brink of locating a “death gene” that holds the key to whether cells become cancerous. The gene is believed to be part of the normal internal controls that ensure cells do not live forever. When it fails, cells can become “immortal” — multiplying endlessly to form a cancerous growth.
As the cells cannot be “switched off”, they overwhelm healthy tissue. Understanding why the gene goes wrong will provide important clues for developing new treatments to kill off tumours.
Ken Parkinson, who is heading the project at the laboratories of Cancer Research UK in Glasgow, has been searching for the crucial gene for five years, and now believes that he and his colleagues are on the verge of finding it.
Parkinson said that a defective version of the gene could be present in as many as 90 per cent of certain lung cancers, half of all cases of cervical cancer and liver cancer, and a third of throat cancers. A therapy that replaced the effects of the gene could benefit significant numbers of cancer sufferers.
“Normal cells cannot divide forever but a high percentage of cancer cells do have this property,” he said.
“This could be one of the explanations for why cancers can grow back. If we can find the genetic fault responsible for their survival we can begin to look at ways of making the cells vulnerable to dying once again.”
A key piece of evidence in the team’s search for the death gene was the discovery that malignant cells from patients with cervical cancer are missing a crucial piece of genetic material, or DNA.
The deleted section, they found, is on chromosome number four, one of 23 paired parcels of genetic material found in bodily cells. When they replaced this missing material artificially in laboratory tests, the malignant cells died.
Parkinson said there were “hints” that the death gene that he is chasing may also be involved in breast and colon cancer, though the evidence was not clear-cut.
The potential impact of the gene is substantial: in Britain cervical cancer kills around 1,200 women a year; lung cancer kills around 20,000 men annually, and cancer of the throat and liver accounts for around 7,000 deaths.
Parkinson said he and his colleagues have now traced the crucial gene to a tiny section of genetic material that contains only five to 10 genes in all. He added: “It may take us a further three years to identify the gene but if we’re lucky we may get it in a year.”