Dangerous viral infections 'could be used in war against cancer'Common viruses sometimes attack cancer tumours
21:27 GMT, 21 March 2012
Dangerous viral infections could be the latest weapon in the war against cancer.
Specially tailored infections could soon be used to help tackle the deadly disease and stop the cancer cells dividing.
Scientists in America have been trying to create viruses
that are weak so they don't damage healthy cells but strong enough to
destroy cancer cells.
Specially tailored infections – like the herpes virus pictured – could soon be used to help tackle the deadly disease
Dr Robert Martuza, chief neurosurgeon at
the Massachusetts General Hospital and professor of neuroscience at
Harvard Medical School, told the New York Times: 'It’s a very exciting time. I think it will work out in some tumor, with some virus'.
Doctors have known that viruses can weaken cancer since the turn of the century.
However, early efforts to use this knowledge to cure patients largely failed as recovery was only temporary and sometimes sufferers died of the infection.
Research into cures then shifted to other treatments.
But now following new understanding about genetics and how viruses and cancers work together, doctors have realised that specially tailored viruses might be the answer.
At the moment several potential cancer-fighting viruses are in trials.
There are flu-like side effects to the viruses, however doctors say these are much easier to manage than the effects of chemotherapy
A form of the herpes virus is being tested on skin cancer, and vaccinia, the virus used to protect against smallpox is being tested on liver cancer, which is the third cause of cancer deaths across the world.
Other viruses are being tested against bladder, head and neck cancers.
In one trial the survival time for some patients doubled.
There are flu-like side effects to the viruses, however doctors say these are much easier to manage than the effects of chemotherapy.
Dr Martuza began looking at how the herpes virus could fight cancer in 1991.
He injected the a weakened form of the virus into mice with brain cancer and the disease in the rodents went into remission.
However, they died of encephalitis.
In 1990 a virologist in Chicago discovered that when a particular gene in herpes was removed it slowed the growth of cancer cells.
Six years later another virologist adapted the herpes virus again and found a way that it did not attack the immune system.