London, Oct 30 : British scientists have developed a new cancer therapy that uses ultra-violet light to destroy tumours.

The team, from Newcastle University, has developed light-activated "magic bullets" which could give hope to millions of cancer victims by allowing surgeons to target tumours much more successfully.

The team has synthesized a way to prevent antibodies becoming effective until illuminated with UV light, meaning they can target specific cancers while remaining inactive in other parts of the body.

The special molecules are injected into the bloodstream and then "switched on" by shining ultraviolet light on the part of the body where they are needed.

Since these special molecules only work when bathed in light, doctors would be able to use ultraviolet rays to make sure that only the drugs embedded near the tumour are switched on.

The team hopes the procedure could be used to make existing drugs such as Herceptin much more effective.

"I would describe this development as the equivalent of ultra-specific magic bullets,” the Daily Mail quoted lead researcher Professor Colin Self, as saying.

He added that the technique could be used for tumours close to the skin, such as breast cancer, and for any cancers within reach of a light probe.

These include those of the digestive system, such as stomach and bowel cancer, and those of the genito-urinary system, such as ovarian cancer.

The team firstly demonstrated how they could coat an antibody in oil so that it does not react with substances within the body except when illuminated.

In a second study, mice with ovarian cancer were injected with antibodies known to stimulate immune responses to the tumours.

They found that in their uncoated form, the antibodies significantly reduced the weight of the tumours in three weeks. However, the combination of "cloaked" antibodies and UV light caused "a massive decrease in subsequent tumour growth to the extent that no trace of tumour was detectable" in 83 per cent of laboratory mice.

"This could mean that a patient coming in for treatment of bladder cancer would receive an injection of the cloaked antibodies. Just a few minutes of the light therapy directed at the region of the tumour would activate the T-cells causing her body's own immune cells to attack the tumour,” Self said.

The researchers are now seeking funding for a trial in human skin cancer patients early next year.

The research is published in the journal ChemMedChem. (ANI)