Microbeam offers hope to cancer sufferers

A ‘MICROBEAM’ that zaps individual cancer cells with a stream of particles could revolutionise radiotherapy, it was revealed yesterday.

British researchers found that the beam caused targeted cells to send a wave of suicidal signals out to their neighbours.

The ‘bystander’ effect meant that many more cancer cells were killed than were actually hit by the particles.

In future, the technology could help to make radiotherapy a more potent weapon against tumours and less damaging to healthy tissue.

Scientists at Cancer Research UK’s Gray Cancer Institute helped develop the microbeam, which fires a stream of charged helium particles just a thousands of a millimetre wide. To test the beam’s effects, they studied brain cancer cells grown in the laboratory that were highly resistant to conventional radiotherapy. The researchers targeted single cells in a culture dish with the beam. They found that hitting just one cell among 1,200 sent a significant number of its neighbours on the path to suicide. By hitting just a few cancer cells, the scientists were able to trigger extensive waves of cell-death.

Cancer Research UK’s Dr Kevin Prise, heading the experiments at the Institute in Northwood, north-west London, said: “We used to assume that the only way to kill cancer cells with radiotherapy was to hit every one with a fatal dose of radiation. Now we’re finding that it’s possible to hit just a handful of cells with much lower doses and let the cells’ natural suicide machinery do the rest.

“Our discovery has important implications both for optimising the effectiveness of radiotherapy and for protecting healthy tissue from its effects. “If we could enhance the bystander effect within tumours, we could develop much more effective systems of radiotherapy, perhaps using lower doses to reduce side effects,” he said.

The new study, reported in the journal Cancer Research, showed that the bystander effect relied on nitric oxide. This is a naturally produced substance which plays an important role in a cell’s response to stress.