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[00:01.00]American and British scientists are using genetically changed viruses to seek and destroy cancer cells.
[00:11.65]A new study shows that a changed cold virus injected into tumors shrinks them with lasting effects when combined with anti-cancer drugs.
[00:25.37]The new treatment is showing promise in the treatment of head and neck cancers.
[00:32.45]Almost five-hundred-thousand people suffer head and neck cancers every year.
[00:40.02]Viruses and cancers work by invading tissue cells and taking control of them.
[00:48.90]Using a process called gene therapy,scientists changed the genes of a virus so that it would target cancer cells.
[01:00.58]The cancer cells are killed as the virus takes over.However,the virus does not damage normal cells.
[01:10.72]The virus used in the study is called ONYX-Zero-One-Five.
[01:18.29]Researchers developed it to destroy cells that have a changed tumor suppressor gene called P-Fifty-Three.
[01:28.45]Changes in the P-Fifty-Three tumor suppresor gene are linked to up to seventy-percent of cancerous head and neck tumors.
[01:41.33]Scientists report that the combination of the infected changed virus and anti-cancer drugs reduced head and neck tumors in twenty-five of thirty people tested.
[01:58.76]They said cancerous tumors disappeared in eight people.
[02:03.95]And they said in other people,the tumors shrank.
[02:09.05]The researchers combined the virus treatment with powerful chemicals used in traditional cancer treatment.
[02:19.37]These chemicals are called chemotherapy drugs.
[02:24.46]The scientists say that ONYX-Zero-One-Five in combination with chemotherapy is more effective than either treatment alone.
[02:37.05]They say tumors grew back in earlier studies that did not include both treatments.
[02:44.71]But,researchers say none of the tumors treated with the combination treatment had grown after six months.
[02:54.97]Scientists say the study is one of the most successful yet using gene therapy.
[03:02.16]They also have begun testing the combination treatment on larger groups of people.
[03:09.63]The study involved only people with cancer of the head of neck.
[03:16.44]Yet the researchers expect the virus treatment to work on other tumors that contain changed P-Fifty-Three genes.
[03:27.42]And they hope the treatment may be effective against cancers that have spread to other parts of the body.
