The technology enables the first steps towards Star Trek medicine

Ed Hubbard, United Devices

The project - a collaboration between Oxford University, UK, and an American technology company - hopes to reach millions of home computers around the world.

And if successful, the British-designed software could accelerate research into new cancer drugs by several years.

The screensaver can be downloaded free from United Devices, the company behind the Seti@home project, which uses unused computing power to search the skies for extraterrestrial life.

Click here for details of how to download the software

Scientists have developed software which enables the spare capacity of PCs to be used to screen molecules for potential anti-cancer activity.

In effect, this will lead to the creation of a virtual super-computer that will be able to screen up to 250 million chemicals. Using just one computer, even one of the most sophisticated models, it would not be possible to process such a volume of information for decades.

Professor Graham Richards hopes thousands of people will help

The project is based at Oxford University, but will be launched in California on Tuesday.

A US charity, the National Foundation for Cancer Research, and two US companies, United Devices and Intel, have also been involved in the development of the technology, known as peer-to-peer (P2P) networking.

Studies estimated that average office workers might only use up to 20% of the power available on their PCs. The aim of the project is to harness that untapped power to process information on the molecules and send it back to a central server.

Initial package

Each subscribing computer will receive an initial package of 100 molecules over the internet, together with a drug-design software application called Think and a model of a target protein known to be involved in causing cancer.

People now have the opportunity to make a positive impact on the disease by donating their unused computer power

Professor Graham Richards, Oxford University

Think evaluates the molecules for cancer-fighting potential by creating three-dimensional computer models of them and testing their interactions with the target protein.

When a molecule successfully interacts with a protein, it will register as a hit and will be sent back to a central server for further investigation.

The scientists are initially looking for molecules which could inhibit the enzymes which stimulate the blood flow to tumours, and work against proteins which are responsible for cell growth and cell damage.

It is envisaged that the project will continually expand as new drug targets are identified.

Many sufferers

Professor Graham Richards, director of the Centre for Drug Discovery at Oxford University, said: "One in four people throughout the world contract some form of cancer, so nearly everyone will have a relative, friend or colleague who has suffered or is suffering from the disease.

"People now have the opportunity to make a positive impact on the disease by donating their unused computer power, which will enable us to accelerate our programme of research, and come up with many new molecular candidates that could be developed into cancer drugs."

Ed Hubbard, CEO of United Devices, said: "Internet-distributed computing allows scientists and organisations to consider projects previously considered impossible due to resource constraints, including time and money.

"Essentially, the technology enables the first steps towards Star Trek medicine."

Professor Michael Sternberg, head of the biomolecular modelling laboratory at the Imperial Cancer Research Fund, said lengthy laboratory research would be needed on the candidates before any anti-cancer drugs were developed.

He said: "This is just the first step in designing drugs to treat cancer."

It is expected that up to 100,000 molecules will show potential for fighting cancer.