CANCER scientists in the North-East have made a huge breakthrough in the search for a cure.

The experts from Newcastle University have developed a revolutionary way of using light to attack and destroy cancer in the human body.

The development is being hailed as a breakthrough in the battle against Britain's biggest killer.

Tests have also suggested the treatment may boost the body's immune system to fight off the disease and prevent it coming back.

Like a sniper using a laser beam on a rifle to target a victim, the Newcastle University researchers Professor Colin Self and Dr Stephen Thompson have found a way of harnessing ultraviolet light beams so that so-called "magic bullet" drugs attack only cancer cells, rather than healthy tissue.

Prof Self and Dr Thompson have developed a procedure to "cloak" antibodies, contained in cancer drugs, with a light-sensitive coating.

This coating is shed when the ultra-violet light is directed onto the antibodies.

The activated antibodies then attack the nearby cancer cells by harnessing the body's immune system.

It is thought that by using a delivery system such as a flexible endoscope tube or by keyhole surgery, doctors will be able to shine light into virtually every part of the body.

While the process has been tested only on mice, it works so well that the scientists are looking to begin clinical trials on patients with secondary skin cancers early next year.

This approach to cancer therapy, which harnesses the body's immune system, has the potential to enhance the cancer-killing potential of a whole new generation of therapeutic antibodies developed by drug companies.

These antibody therapies, including high-profile treatments such as the breast cancer drug Herceptin and the bowel cancer drug Avastin, have been designed to attack specific types of cancer and rely on stimulating the body's defence system.

But the problem with this family of drugs has been that they have to be injected into the bloodstream - and they often attack healthy tissue as well as cancer cells.

Prof Self explained how the treatment would work. He said "This could mean that a patient coming in for treatment for bladder cancer would receive an injection of the cloaked antibodies.

"She would sit in the waiting room for an hour and then come back in for treatment by light.

"Just a few minutes of the light therapy directed at the region of the tumour would active the patient's T-cells, the body's defence system, causing her body's own immune system to attack the tumour."

Dr Thompson said the tests on mice have shown the potential of the treatment.

He said: "We were able to show that in some mice the tumour completely disappeared."

Results of trials involving mice are to be published in due course.

Today's scientific papers, published online in the journal ChemMedChem, demonstrate the procedure of coating, or cloaking, the surface of a protein, such as an antibody, and how it can be activated by ultra-violet light to encourage a patient's immune system to attack cancer cells.

In the second paper, the Newcastle scientists show that when the cloaked antibodies are activated by light near a tumour, the tumour is killed.

Prof Self said they believed the approach could also be used with the next generation of antibodies produced by drug companies to combat a wide variety of cancers.

Known as bispecific complexes, these are formed from two antibodies, one which binds to a tumour, the other to part of the immune system known as a T-cell, which confront and attack intruders.

This means that when the bispecific antibody binds to healthy tissues away from light it cannot activate T-cells, resulting in far fewer side effects.

An example of this would be to combine the light therapy approach with bispecific antibodies developed to fight prostate cancer.

Prof Self said in this way it should be possible after a surgeon has removed most of a patient's tumour to mop up any remaining prostate cancer cells by using light to trigger bispecific antibodies.

BioTransformations, a company set up by Prof Self to develop the technology, has been working with Cels Ltd, a Newcastle-based organisation set up to encourage growth in the North-East's healthcare economy.

Mike Asher, chief executive of Cels, said the work of Prof Self and Dr Thompson appeared to be "a potential breakthrough in the fight against cancer".