Melanoma and Obesity Connection
From: Andy Soos, ENN.com
A gene linked to obesity
and over eating may also increase the risk of malignant melanoma — the most
deadly skin cancer, according to scientists at the University of Leeds. The
research, funded by Cancer Research UK, shows that people with particular
variations in a stretch of DNA within the FTO gene, called intron 8, could be
at greater risk of developing melanoma.
Variations in a
different part of the FTO gene, called intron 1, are already known to be the
most important genetic risk factor for obesity and overeating.
Fat mass and
obesity-associated protein also known as alpha-ketoglutarate-dependent
dioxygenase FTO is an enzyme that in humans is encoded by the FTO gene located
on chromosome 16. Certain variants of the FTO gene appear to be correlated with
obesity in humans.
These variants are
linked to Body Mass Index (BMI) — a measure of a person’s shape based on their
weight and height. Having a high BMI can increase the risk of various diseases
including type 2 diabetes, kidney disease, womb (endometrial) cancer and more.
But this research is the
first to reveal that the gene affects a disease — melanoma — which isn’t linked
to obesity and BMI.
The results suggest that
FTO has a more wide-ranging role than previously suspected, with different
sections of the gene being involved in various diseases.
Dr Mark Iles from the
University of Leeds, said: "This is the first time to our knowledge that
this major obesity gene, already linked to multiple illnesses, has been linked
to melanoma. This raises the question whether future research will reveal that
the gene has a role in even more diseases?"
"When scientists
have tried to understand how the FTO gene behaves, so far they’ve only examined
its role in metabolism and appetite. But it’s now clear we don’t know enough
about what this intriguing gene does."
"This reveals a hot
new lead for research into both obesity-related illnesses and skin
cancer."
The researchers examined
tumor samples in more than 13,000 melanoma patients and almost 60,000
unaffected people from around the world.
Melanoma is less common
than other skin cancers. However, it is much more dangerous if it is not found
early. It causes the majority (75%) of deaths related to skin cancer.
Worldwide, doctors diagnose about 160,000 new cases of melanoma yearly. In
women, the most common site is the legs and melanomas in men are most common on
the back. It is particularly common among Caucasians, especially northwestern
Europeans living in sunny climates. There are high rates of incidence in
Oceania, Northern America, Europe, Southern Africa, and Latin America, with a
paradoxical decrease in southern Italy and Sicily.
Dr Julie Sharp, Cancer
Research UK’s senior science information manager, said: “These are fascinating
early findings that, if confirmed in further research, could potentially
provide new targets for the development of drugs to treat melanoma.
"Advances in
understanding more about the molecules driving skin cancer have already enabled
us to develop important new skin cancer drugs that will make a real difference
for patients."
"But it doesn’t
detract from the importance of reducing your risk of the disease by enjoying
the sun safely on winter breaks abroad and avoiding sunbeds. Getting a painful
sunburn just once every two years can triple the risk of melanoma."
The research is
published today in Nature Genetics.
For further information
see Genes and
Melanoma.
