More news from the cancer front

From the New Scientist:

GM virus shrinks cancer tumours in humans

A virus carefully engineered to target cancer tumours has shown promising results in treating liver cancer in a small, early-stage clinical trial.

Some of the patients enrolled in the trial experienced a greater than 50% reduction in the size of their tumours over the course of the year long study, according to researchers. The virus used in the treatment works well, they say, because it can replicate and spread quickly within the tumours.

Scientists have suspected that viruses might help thwart tumours ever since 1912. In that year, an Italian gynaecology journal reported that a woman with advanced cervical cancer showed signs of increasing tumour shrinkage after receiving a rabies vaccination for a dog bite.

[…]

To overcome this challenge scientists such as David Kirn at Jennerex Biotherapeutics in San Francisco, California, US have tried to develop treatments based on the vaccinia or pox virus. This spreads more easily within cancer tumours than previously employed viruses thanks to a 'tail' composed of a protein called actin.

In the first step, Kirn's team deleted a gene from the vaccinia virus that made it unable to produce an enzyme called thymidine kinase. Without this enzyme, the virus cannot replicate and cause damage in normal, healthy tissue.

Cancerous cells, however, contain an abundance of thymidine kinase, making it easy for the modified vaccinia virus to multiply within tumours. And once the virus creates enough copies of itself it bursts the cancer cell where it resides.

Next, Kirns' group added a gene to the virus that made it produce a signalling molecule called cytokine, which attracts the body's immune cells towards tumours. The end result of this elaborate process of genetic engineering was a tumour-targeting vaccinia virus known as JX-594.

Hopeful signs all over. Europeans will not want this, I suppose, because of the genetic engineering involved.