‘Sunscreen gene’ discovery could help doctors predict who’s most at risk of melanoma cancer

May 19, 2016

Rosie Taylor for the Daily Mail

Published:
11:00 EST, 19 May 2016

|
Updated:
14:34 EST, 19 May 2016

View
comments

A ‘sunscreen gene’ may help protect people against skin cancer, scientists have discovered.

The gene helps cells to repair after they have been damaged by UV rays from the sun or sunbeds.

People who have low levels of the gene or a mutated version of it will not be able to repair the damage properly, leaving them at greater risk of developing skin cancer.

Researchers from the University of Southern California said the discovery could help doctors understand which people are at highest risk of developing melanoma.

Melanoma, a skin cancer that can spread to other organs in the body, is the UK’s fifth most common form of cancer, with 13,000 new cases diagnosed annually.

Around 2,000 people every year die from the disease in the UK.

People who have low levels of the gene or a mutated version of it will not be able to repair the damage properly, leaving them at greater risk of developing skin cancer

For the study, published in the journal Molecular Cell, researchers analysed the ‘UV radiation Resistance Associated Gene’.

They gave a UV shot to cells carrying the normal UV-resistant gene and to cells carrying either low levels or mutated copies of it.

They found that, after 24 hours, cells with the normal version of the gene had repaired more than 50 per cent of the damage caused by the UV, but those with the defective gene had repaired less than 20 per cent of the damage.

Chengyu Liang, the study’s senior author, said: ‘That means when people sunbathe or go tanning, those who have the normal UV-resistant gene can repair most UV-induced DNA burns in a timely manner, whereas those with the defective UV-resistant gene will have more damage left unrepaired.

‘After daily accumulation, if they sunbathe or go tanning often, these people will have increased risk for developing skin cancers such as melanoma.’

She added: ‘People who have the mutated UV-resistant gene or low levels of the UV-resistant gene may be at higher risk of melanoma or other skin cancers, especially if they go sunbathing or tanning frequently.’

Scientists first discovered the UV-resistant gene nearly 20 years ago but had not previously examined how it works.

They have now found it is a ‘tumour suppressor’ that works by supporting cells to repair damage to DNA.

The gene helps cells to repair after they have been damaged by UV rays from the sun or sunbeds

When a cell is damaged by UV, a protein scans it for damaged DNA. If it finds lesions, it triggers the action of the UV-resistant gene.

Researchers said the gene then worked to support repair, like ‘a humanitarian convoy dropping off reinforcements or aid to help damaged areas repair at precisely the right time’.

Yongfei Yang, lead author, said: ‘When the UV-resistant gene is lost, the cell cannot efficiently repair UV- and chemical-induced damage… Although it may not be the direct doer, without it, the whole structure collapses.’

The study showed a correlation between a lack of the gene and increased cancer risk but did not definitively say diminished levels or mutant copies of the UV-resistant gene caused skin cancer to develop.

Future studies on mice will aim to give scientists a better understanding of how the gene functions.

In future, drugs which stimulate the gene could be used as a treatment for people at high risk of developing skin cancer.