Fungus may be key to cancer treatment

PUBLISHED : Tuesday, 20 December, 2011, 12:00am
UPDATED : Tuesday, 20 December, 2011, 12:00am


A molecule found in a tropical mushroom could turn a potentially toxic element into a weapon against breast cancer, according to researchers at Polytechnic University.

The scientists discovered that a naturally occurring polysaccharide, or complex carbohydrate, in the Tiger Milk mushroom (Lignosus rhinocerus), stabilises selenium, limiting its harmful effects and turning it into a potential cancer remedy.

Selenium, a trace element essential to human health, can be toxic if consumed in excessive amounts, and scientists have long struggled to control its unstable nanoparticles to bring out its healing properties.

'Selenium can kill both good and bad cells, so it was highly risky to use as a treatment before,' Dr Wong Ka-hing, associate director of the university's Food Safety and Technology Research Centre, said.

'But the extracts from the Tiger Milk mushroom were found to have a stabilising force on the selenium nanoparticles. Our tests produced highly stable selenium nanoparticles that will kill only the cancer cells, without harming the good cells.'

The modified nanoparticles were found to have their best performance in destroying breast cancer cells, but the team will also investigate their effect on other tumours.

The next stage is to test the substance on animals and it is expected it will be at least 10 years before a drug can be developed.

The university has partnered with a Tiger Milk mushroom farm to provide it with enough raw material for its research.

However, Wong warned cancer sufferers that the mushroom itself had no particular cancer-curing effects and taking selenium on its own could be extremely harmful.

Doctors suggest daily consumption of selenium should be within 2.4mg to 3mg - any higher dosage might cause liver damage.

Meanwhile, researchers at the University of Hong Kong successfully tracked gene mutations that cause stomach cancer.

The cancer driver gene known as ARID1A, one of the 20 types identified, was found in a mutated form in 70 to 80 per cent of stomach tumours.

Although it is not known how many mutations must accumulate to turn a normal stomach cell into a cancer cell, the team believes the more genes they know about, the better the chances of developing targeted drugs. These are drugs that can selectively kill cancer cells carrying the specific mutation and leave others unharmed.