Primary colours combine to curb cancer

A colourful combination of red light, blue dye and a plant hormone can be used to kill cancer cells with a lethal flurry of chemicals, according to a study by Cancer Research UK scientists, published today.

Researchers believe that they have discovered a way of overcoming problems with normal forms of photodynamic therapy which involves destroying tumours with beams of light.

Their new study – in the prestigious journal Cancer Research – shows that the treatment could be much more effective when combined with a plant hormone that in nature helps plants grow towards the sun.

Scientists, based at the Gray Cancer Institute in Middlesex, treated cancer cells with a special blue dye that becomes chemically energised in response to light. When they shone red light on to the cells and dye with the plant hormone, the hormone shattered to produce toxic chemicals called free radicals. These form poisonous by-products with the potential to kill cancer cells.

The problem with conventional photodynamic therapy is that the dye relies on activating molecules of oxygen to kill tumour cells and therefore doesn’t work in the low oxygen conditions that exist in many tumours.

But the new method uses molecules of plant hormone to attack cancer cells instead and so could work right in the core of many tumours, where oxygen levels are often very low.

Prof Peter Wardman, who led the study for Cancer Research UK, says: “Overcoming this oxygen problem is a major challenge in cancer therapy. So far we have shown this works with cells in dishes, but because both the dye and the plant hormone are known to be non-toxic in man, we are hopeful that we can quickly translate this treatment into clinical reality”.

Sir Paul Nurse, Chief Executive of Cancer Research UK, says: “This is fascinating work in that it combines using clever technology with something provided by nature – the plant chemicals. It is a further step in the direction of producing a therapy that directly targets the tumour.”

ENDS