LONDON: Four new areas on human chromosomes that hold genes related to the risk of developing melanoma, the most dangerous type of skin cancer, have been identified.
In two studies to be published in this week's issue of Nature Genetics, researchers have examined the DNA of several thousand melanoma patients, and compared that to DNA of healthy controls. They hope their discoveries could one day help identify individuals prone to developing melanoma to ensure suitable precautions and early diagnoses.
"This new finding is exciting as early diagnosis is critical in melanoma to improve the outcome of people who develop the disease," said lead author Stuart MacGregor, researcher at the Queensland Institute of Medical Research in Brisbane.
Assessing the risk of melanoma
Scientists have previously identified other areas on the chromosome - called genetic loci - that encode traits that make people susceptible to the development of skin cancer. The composition of a genetic locus differs from one person to the other, and this diversity is referred to as a variant.
Most gene variants that have previously been shown to be associated with an increased risk for melanoma are related to a fair skin tone, blue or green eyes, blonde or red hair and a high mole count.
Now the new studies, one led by researchers in Brisbane and the other by researchers at the Cancer Research UK Centre in Britain, report of four novel variants unrelated to these usual pigmentation risk factors.
These variants may instead favour development of melanoma by interfering with the skin cells' ability to repair DNA damage caused by UV radiation, or they may play a critical role in the control of cell proliferation and cell death.
Examining DNA
The two groups of scientists have independently performed genome-wide association studies (GWAS), in which an individual's DNA, obtained from a cell sample, is examined and compared to other individuals' DNA.
By associating the discovered gene variations with certain traits, such as physical appearance or a disease, it is possible to identify novel genes linked to certain conditions.
In their respective GWAS studies, the scientists compared varieties in the DNA of several thousand melanoma patients to equally large numbers of healthy controls. The research group in Australia, led by MacGregor, has identified a variant locus on chromosome 1 that correlated with risk of melanoma, while the researchers in the UK discovered three loci on chromosomes 2, 11 and 21.
Screening the population
For now, it is only known that the loci are different in healthy individuals as compared to melanoma patients. Determining exactly what different genes in these newly discovered loci do is the next step on the scientists' agenda. "This could potentially give us novel insights into how melanoma develops and how we can either prevent or treat it", said co-author Mark Iles from the Cancer Research UK Centre.
When asked whether their findings could be used to screen an entire population to determine individual risk for melanoma, Iles emphasised that the newly discovered variants alone don't influence the risk of developing melanoma enough for such large-scale screenings to be worthwhile. However, the discoveries may prove beneficial for future genetic scanning of "individuals already known to be at higher risk, such as people who have a close relative with melanoma, but further work is needed to evaluate this", he added.
Development of new therapies
Veronique Bataille, an expert in the field of genetic research and melanoma who was not involved in either study, finds the discoveries encouraging. "They may be interesting for the pathophysiology of the disease and help us understand better the relative contribution of genetic and environmental risk factors," she said.
But she acknowledged that there is a long way to go. "Like all cancers, melanoma is likely to be influenced by a large number of genes each having a small effect and dissecting this may take quite a while. We have to wait and see if these variants come up with successes in terms of genetic pathways and treatment."
Source: http://www.cosmosmagazine.com/news/4825/new-areas-dna-linked-skin-cancer
kia sorento james dean tv guide listings buddy holly buddy holly baylor prime numbers
No comments:
Post a Comment