Virus ‘taught’ to obliterate cancer cells
ATREATMENT that can completely destroy cancer cells without affecting healthy cells could soon be a possibility thanks to research led by Cardiff University.
A team has successfully “trained” a respiratory virus to recognise ovarian cancer and completely destroy it without infecting other cells.
The reprogrammed virus could also be used to treat other cancers such as breast, pancreatic, lung and oral.
Dr Alan Parker, from Cardiff University’s School of Medicine, said: “Reprogrammed viruses are already being used in gene therapy procedures to treat a range of diseases, demonstrating they can be trained from being lifethreatening into potentially life-saving agents.
“In cancer treatment up until now reprogrammed viruses have not been able to selectively recognise only the cancer cells and would also infect healthy cells, resulting in unwanted side-effects.
“We’ve taken a common, well-studied virus and completely redesigned it so that it can no longer attach to noncancerous cells but instead seeks out a specific marker protein called αvα6 integrin, which is unique to certain cancer cells, allowing it to invade them.
“In this case we introduced the reprogrammed virus to ovarian cancer, which it successfully identified and destroyed.
“This is an exciting advance offering real potential for patients with a variety of cancers.”
Once the virus enters the cancer cell it uses the cell’s machinery to replicate, producing many thousands of copies of itself, prior to bursting the cell and thereby destroying it in the process.
The newly released viral copies can then bind and infect neighbouring cancer cells and repeat the same cycle, eventually removing the tumour mass altogether.
The virus also activates the body’s natural immune system, helping it to recognise and destroy the malignant cells.
The reprogrammed virus is from a group of respiratory viruses called adenoviruses. The advantage of using these viruses is that they are relatively easy to manipulate and have already been safely used in cancer treatment.
The technique used to reprogramme the virus to identify the protein common to ovarian, breast, pancreatic, lung and oral cancers could also be used to manipulate it so it would recognise proteins common to other groups of cancers.
Additional refinement to the viral DNA could also allow the virus to produce anti-cancer drugs, such as antibodies, during the process of infecting cancer cells.
This effectively turns the cancer into a factory producing drugs that will cause its own destruction.
The research was carried out in a laboratory using mice with ovarian cancer and has not yet reached clinical trials.
The next step is to test the technique with other cancers with a view to starting clinical trials in five years.
Dr Catherine Pickworth, from Cancer Research UK, said: “The next step will be more research to see if this could be a safe and effective strategy to use in people.”