How skin cancer cells evade immune system: study

January 18, 2011 by Marlowe Hood

Scientists have pinpointed a molecular mechanism in mice which helps skin cancer cells confound the animal's immune system, according to a study released Wednesday.

The discovery -- if duplicated in humans -- could one day lead to drug treatments that block this mechanism, and thus the cancer's growth, the study reported.

In experiments on mice, researchers showed for the first time that a protein called interferon-gamma (IFN-gamma) plays a key role in the spread of melanoma, a notoriously aggressive form of resistant to standard chemotherapy.

The same kind of that leads to sunburn caused white blood cells to infiltrate the skin of the mice, explained Glenn Merlino, a scientist at the US National Cancer Institute and the main architect of the study.

The white blood cells, in turn, "can produce IFN-gamma. We believe that IFN-gamma can promote melanoma in our model system, and perhaps in people," he said in an email.

Injecting the mice with antibodies that block IFN-gamma interrupted this signalling process, effectively reducing the risk of UV-induced , the researchers found.

"We are trying to develop inhibitors that are more practical than antibodies, a small molecule, for example," Merlino said.

Ideally, such a treatment would mean that someone exposed to large doses of -- long summers at the beach without protective cream, for example -- could escape the potentially lethal threat of skin cancer.

"But we would never encourage intense sunbathing, even if such a treatment were available," Merlino cautioned.

Cases of cutaneous malignant melanoma are increasing faster than any other type of cancer.

In 2000, over 200,000 cases of melanoma were diagnosed and there were 65,000 melanoma-associated deaths, according to the World Health Organisation (WHO).

The findings, reported in the British-based science journal Nature, could upend assumptions about the relationship between interferon proteins and cancer, the study suggested.

Up to now, interferons were thought to impede the formation of cancer tumours. One in particular, interferon-alpha, has been widely used to treat , both as a first-line drug and an adjutant.

Earlier research has raised doubts as to effectiveness of the treatment, which also has serious side effects.

The highest recorded incidence was in Australia, where the annual rates are 10 and over 20 times the rates in Europe for women and men respectively.

The main risk factors are high exposure to the sun and other UV sources such as sunbeds, along with genetic factors.

The disease is far more common among people with a pale complexion, blue eyes, and red or fair hair.

Related Stories

Recommended for you

Study prompts new ideas on cancers' origins

December 16, 2017
Rapidly dividing, yet aberrant stem cells are a major source of cancer. But a new study suggests that mature cells also play a key role in initiating cancer—a finding that could upend the way scientists think about the ...

What does hair loss have to teach us about cancer metastasis?

December 15, 2017
Understanding how cancer cells are able to metastasize—migrate from the primary tumor to distant sites in the body—and developing therapies to inhibit this process are the focus of many laboratories around the country. ...

Cancer immunotherapy may work better in patients with specific genes

December 15, 2017
Cancer cells arise when DNA is mutated, and these cells should be recognized as "foreign" by the immune system. However, cancer cells have found ways to evade detection by the immune system.

Scientists pinpoint gene to blame for poorer survival rate in early-onset breast cancer patients

December 15, 2017
A new study led by scientists at the University of Southampton has found that inherited variation in a particular gene may be to blame for the lower survival rate of patients diagnosed with early-onset breast cancer.

Scientists unlock structure of mTOR, a key cancer cell signaling protein

December 14, 2017
Researchers in the Sloan Kettering Institute have solved the structure of an important signaling molecule in cancer cells. They used a new technology called cryo-EM to visualize the structure in three dimensions. The detailed ...

'Bet hedging' explains the efficacy of many combination cancer therapies

December 14, 2017
The efficacy of many FDA-approved cancer drug combinations is not due to synergistic interactions between drugs, but rather to a form of "bet hedging," according to a new study published by Harvard Medical School researchers ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

fixer
not rated yet Jan 18, 2011
And does Glenn Merlino know that mice and humans have significantly different immune systems and that using mice to develop immune therapies for humans is usually just a waste of mice?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.