By Michael Sohn, Toronto Star/Toronto Star Reporter, Toronto-Dominion Bank (OTTAWA) It’s a question that has baffled scientists and doctors alike.
But a new study in The Lancet says it could help explain why some people are more likely to develop a specific type of cancer called melanoma than others.
The study is the first to show a link between a genetic variation in a gene called MC1R and melanoma, which is one of the leading causes of skin cancer worldwide.
And the researchers found the genetic variation appears to be a strong predictor of whether melanoma develops in people who have already had the mutation.
“The findings provide evidence that some individuals with MC1r variant are more at risk for melanoma development, whereas others do not,” the study authors wrote.
“These results support the idea that melanoma is a common cancer inherited from one generation to the next and that a person’s genetic variation may contribute to risk for this cancer.”
The study also suggests a connection between the MC1 receptor gene and melanomas.
Researchers at Imperial College London looked at melanoma cases in 10 European countries between 1980 and 2015.
The results, published in the journal Molecular Genetics, are the most detailed look yet at the genetic differences in melanoma.
They found the MC2R gene has been found to be the strongest predictor of melanoma and the MC4R gene was most strongly linked to melanoma progression.
“It’s a remarkable finding, as the gene is not found in people with other types of cancer,” said study co-author Dr. Paul Ehrlich, of the Centre for Genetics in Medicine and Biology at Imperial.
He said there was a strong correlation between melanoma risk and the number of MC1 receptors in the skin.
In fact, the researchers also found that the MC5R gene is a strong genetic predictor of melanomas, suggesting it may be a common gene for the disease.
While many genes have been linked to skin cancer in the past, this is the most comprehensive study of its kind, he added.
The findings are important because they suggest that the genetic makeup of skin cells may play a role in the development of melanoblastomas, said study lead author Dr. Steven A. Kowalczyk, an epidemiologist at the University of Michigan Medical School in Ann Arbor.
“We have identified a new pathway for melanoballoma and that pathway is the MC3R,” he said.
“This means it has been suggested that there may be genes that play a key role in melanoblasts survival.
This pathway has been shown to be very strong in melanocarcinoma patients, so this is very exciting.”
Kowalcyk said the findings show the MC11R gene could also play a major role in skin cancer.
Kawalczy said the finding that MC11 was also strongly associated with melanoma may be due to the MC12R gene, which contains a gene that is linked to the growth of melanocytes, the cells that produce melanin.
The study’s results were based on DNA samples taken from more than 11,000 people in the European Union between 1980-2015.
It looked at MC1 and MC4 genes, and found a strong link between MC1 rs53535 and melanocytic melanoma in people born in the 1980s and 1990s.
They also found the gene was significantly associated with the risk of melanocysts developing in people diagnosed with melanocortin-4 receptor disease, a genetic condition that causes the immune system to produce more melanin than normal.
The researchers said they were unable to determine how much of this gene may be passed down to people with melanocyst-like cancers, but they were hopeful that the findings could help doctors identify people who may have melanoma that is related to MC11.
“One thing that we’re not sure about is whether this MC11-linked risk is universal, and whether this might affect all individuals,” said Dr. Michael Belsky, of Imperial College.
“There’s a lot of research that has shown melanoma patients have more MC11 in their genome than other people.”
Kowalsky said more studies are needed to see if a gene like MC11 plays a role for melanocancer.
Dr. Mark D. Lee, a professor of epidemiology and public health at the Albert Einstein College of Medicine, said there is a lot more to the story.
“When you’re talking about the melanocaras, this might be a gene involved with the immune response, the melanocytosis response, or something else,” he explained.
“What we don’t know is how MC11 relates to other melanocondylomas.”
Dr Lee said he hopes that understanding how MC1 is involved in melanomas could lead to better treatments for people with the disease and for people who do not have it.