Professor Newbold explains the significance of the research

The discovery could pave the way for anti-cancer drugs that would significantly improve treatment for people with malignant melanoma.

That form of skin cancer, although the rarest, is responsible for 1,500 deaths in the UK each year.

The research adds to a growing body of evidence offering an insight to how cancer works.

The announcement comes as the Cancer Research Campaign, which funded the research, launches its Cover Up campaign for 1999.

The campaign aims to educate people about risks of spending too long exposed to the sun - one of the leading causes of skin cancer.

Excitement

Professor Robert Newbold, of Brunel University in west London, led the research.

He said: "This is an exciting discovery. We now know that by placing these genes into the cancer cell they stop malignant melanoma in its tracks."

The relevant genes are tumour suppressor genes (TSGs). They control the growth of cells, and, as cancer is when cells grow uncontrollably, TSGs are essential to prevent healthy cells becoming cancerous.

Scientists had already identified a TSG called P16 as being able to stop the growth of malignant melanoma cells.

The new research placed groups of healthy genes carried on chromosomes-9 and 10 inside cancerous cells and found that they stopped the cells' malignant growth.

In doing so, the researchers discovered another two TSGs that halt growth.

Having identified the genes, scientists will be able to study them further and gain an insight to how they work.

Further studies

Professor Newbold said: "This is really just the beginning, because at this stage we have no idea how the new genes work.

"By finding out more about the their function it may lead to new ways of treating malignant melanoma.

"These findings show that we have successfully identified at least one new gene on chromosome-9 and one on 10 that have the ability to stop the growth and development of malignant melanoma."

He added: "We're really in a golden period of cancer research where for a fairly short period of time, maybe a couple of years, all of the genes that are involved in the major cancers will be discovered and characterised.

"What we're doing is accumulating information, which is the only way that new forms of treatment for cancer will ever be devised."

But he warned that people should not expect too much too soon, as building a complete picture took time.