Viral gene therapy could stop breast cancer from spreading

A new type of gene therapy has been developed by Cancer Research UK scientists which could potentially block the ability of breast cancer cells to spread around the body.

The invention has now been successfully patented by the charity in conjunction with King’s College London. It targets cancer cells with a fragment of DNA called a minigene carried inside a specially modified virus.

Treating women with the virus before surgery could in the future hold cancer cells in place within the tumour, improving the chances of a successful operation.

Researchers targeted the gene therapy at a molecule called PKC alpha, which is involved in helping to instruct cancer cells to move in a particular direction.

They used a minigene that provides the genetic information for a tiny protein molecule, designed to interfere with PKC alpha’s activity. The minigene was carried into breast cancer cells using a virus known as a retrovirus.

Scientists grew cancer cells in the laboratory and tracked their movement in response to signals encouraging them to spread. Uninfected cells moved rapidly in the direction of the signals. But among infected cells, PKC alpha could no longer help cells to respond to signals and their ability to move was reduced by 90 per cent.

Team leader Dr Tony Ng, of the Richard Dimbleby/Cancer Research UK Department of Cancer Research at St Thomas’ Hospital in London, comments: “One of the most distinctive features of a cancer cell is its ability to respond to chemical signals and begin to move through the tissues surrounding it.

“Blocking the ability of cancer cells to follow instructions to move may be an effective way of preventing the disease from spreading.”

Scientists believe that the gene therapy has particular potential against tumours in which PKC alpha is highly active, since these may be especially reliant on the molecule. Doctors might be able to test tumours at the time of diagnosis for the presence of this active molecule in order to identify those best suited to the treatment.

Fellow researcher Dr Peter Parker, of the Cancer Research UK London Research Institute, adds: “In the laboratory the new system has been extremely successful at preventing cancer cells from moving around. We now need to find the best way of getting the virus into tumours, so women with breast cancer could benefit.”

“The treatment might be particularly useful around the time of surgery to remove a tumour, since this is a time when cancer cells may break away from a tumour and spread around the body.”

Sir Paul Nurse, Chief Executive of Cancer Research UK, says: “Over the last few years, there’s been an explosion in our knowledge of the genes involved in cancer’s development and we’re starting to see that translated into treatments that target very specific molecular mechanisms.

“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 should see gene therapy playing an increasing role in cancer treatment.”

ENDS