Nav: Home

'Sunscreen' gene may help protect against skin cancer

May 19, 2016

A new USC-led study identified a "sunscreen" gene that may help stave off skin cancer.

The researchers found that the "UV radiation Resistance Associated Gene" is a tumor suppressor for skin cancer, which is the most common form of cancer in the United States. Melanoma is the deadliest skin cancer. In fact, melanoma rates have doubled over the last three decades, according to the Centers for Disease Control and Prevention.

"If we understand how this UV-resistant gene functions and the processes by which cells repair themselves after ultraviolet damage, then we could find targets for drugs to revert a misguided mechanism back to normal conditions," said Chengyu Liang, the study's senior author and an associate professor of molecular microbiology and immunology at the Keck School of Medicine of USC.

The study was published in Molecular Cell -- in time for Melanoma/Skin Cancer Detection and Prevention Month. More than 90 percent of melanoma skin cancers develop because of cell damage from exposure to UV radiation. Melanoma kills about 10,130 people annually, according to the American Cancer Society.

"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," Liang said. "Our study suggests that the UV-resistant gene may serve as a biomarker for skin cancer prevention."

A shot in the cell

The researchers used data from 340 melanoma patients who participated in The Cancer Genome Atlas. The study also included two experimental groups with either reduced levels of the UV-resistant gene or a mutant copy of that gene in melanoma cells and 50 fly eyes. The control groups were melanoma cells or fly eyes with normal copies of the UV-resistant gene.

The scientists gave a UV shot to cells carrying the normal UV-resistant gene and cells carrying defective copies of it. After 24 hours, cells carrying normal versions of the gene had repaired more than 50 percent of the UV-induced damage. In contrast, the defective samples repaired less than 20 percent of the damaged cells.

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

The researchers were able to show a correlation with increased cancer risk. Their study did not definitively say diminished levels or mutant copies of the UV-resistant gene were causes for skin cancer development.

Why the UV-resistant gene matters

Scientists first discovered the UV-resistant gene nearly two decades ago in relation to a disease called Xeroderma Pigmentosum, which makes people extremely sensitive to sunlight and puts them at high risk for developing skin cancer. Scientists did not examine the function of the UV-resistant gene in people who are healthy or who have skin cancer.

The USC-led team has now identified what the UV-resistant gene does and how it operates in a general population, said Yongfei Yang, lead author and a research associate at Keck Medicine of USC.

"The UV-resistant gene is a tumor suppressor involved in the UV-repair process of a cell's DNA and is essential for preventing UV-induced genomic instability," Yang said. "When the UV-resistant gene is lost, the cell cannot efficiently repair UV- and chemical-induced damage."

The UV-resistant gene is involved in the multistep DNA cell-repair process, researchers found. First a known protein scans for damaged DNA. Once it finds lesions, it tags the UV-resistant gene into action. The UV-resistant gene is like a humanitarian convoy dropping off reinforcements or aid to help damaged areas repair at precisely the right time.

The researchers did not have data from people without skin cancer, so they were unable to compare their observations of melanoma patients with those of skin cancer-free people.

"We found the expression level of the UV-resistant gene is related to melanoma patients' survival and metastasis stages," Yang said. "Lower levels of the UV-resistant gene means a lower survival rate and advanced metastases stages."

The UV-resistant gene brings hope

UV exposure, frequent trips to the tanning salon and genetics all play a role in developing skin cancer. Studies have shown, for example, that redheads are more prone to skin cancer because of their genetic background. Liang, Yang and their colleagues have identified a new player in the skin cancer field.

"To our knowledge, the UV-resistant gene does not have any enzymic activity; It's a supporter or coordinator," Liang said. "Although it may not be the direct doer, without it, the whole structure collapses."

Future studies will use mouse models to better understand how the UV-resistant gene functions.

"The UV-resistant gene may serve as a good target for drug development," Yang said. "Perhaps one day a drug could stimulate the repairing functionality of the UV-resistant gene to ensure swift and effective repair of UV-damaged skin cells. That would be a good treatment for people who are at high risk of developing skin cancer."
-end-
Scientists at Children's Hospital Los Angeles, the Korea Advanced Institute of Science and Technology and the Chinese Academy of Sciences in Beijing also contributed to the study. The Margaret Early Trustee Foundation, American Cancer Society, National Institutes of Health grants and GRL Program from the National Research Foundation of Korea funded the research.

University of Southern California

Related Cancer Articles:

Radiotherapy for invasive breast cancer increases the risk of second primary lung cancer
East Asian female breast cancer patients receiving radiotherapy have a higher risk of developing second primary lung cancer.
Cancer genomics continued: Triple negative breast cancer and cancer immunotherapy
Continuing PLOS Medicine's special issue on cancer genomics, Christos Hatzis of Yale University, New Haven, Conn., USA and colleagues describe a new subtype of triple negative breast cancer that may be more amenable to treatment than other cases of this difficult-to-treat disease.
Metabolite that promotes cancer cell transformation and colorectal cancer spread identified
Osaka University researchers revealed that the metabolite D-2-hydroxyglurate (D-2HG) promotes epithelial-mesenchymal transition of colorectal cancer cells, leading them to develop features of lower adherence to neighboring cells, increased invasiveness, and greater likelihood of metastatic spread.
UH Cancer Center researcher finds new driver of an aggressive form of brain cancer
University of Hawai'i Cancer Center researchers have identified an essential driver of tumor cell invasion in glioblastoma, the most aggressive form of brain cancer that can occur at any age.
UH Cancer Center researchers develop algorithm to find precise cancer treatments
University of Hawai'i Cancer Center researchers developed a computational algorithm to analyze 'Big Data' obtained from tumor samples to better understand and treat cancer.
New analytical technology to quantify anti-cancer drugs inside cancer cells
University of Oklahoma researchers will apply a new analytical technology that could ultimately provide a powerful tool for improved treatment of cancer patients in Oklahoma and beyond.
Radiotherapy for lung cancer patients is linked to increased risk of non-cancer deaths
Researchers have found that treating patients who have early stage non-small cell lung cancer with a type of radiotherapy called stereotactic body radiation therapy is associated with a small but increased risk of death from causes other than cancer.
Cancer expert says public health and prevention measures are key to defeating cancer
Is investment in research to develop new treatments the best approach to controlling cancer?
UI Cancer Center, Governors State to address cancer disparities in south suburbs
The University of Illinois Cancer Center and Governors State University have received a joint four-year, $1.5 million grant from the National Cancer Institute to help both institutions conduct community-based research to reduce cancer-related health disparities in Chicago's south suburbs.
Leading cancer research organizations to host international cancer immunotherapy conference
The Cancer Research Institute, the Association for Cancer Immunotherapy, the European Academy of Tumor Immunology, and the American Association for Cancer Research will join forces to sponsor the first International Cancer Immunotherapy Conference at the Sheraton New York Times Square Hotel in New York, Sept.

Related Cancer Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Digital Manipulation
Technology has reshaped our lives in amazing ways. But at what cost? This hour, TED speakers reveal how what we see, read, believe — even how we vote — can be manipulated by the technology we use. Guests include journalist Carole Cadwalladr, consumer advocate Finn Myrstad, writer and marketing professor Scott Galloway, behavioral designer Nir Eyal, and computer graphics researcher Doug Roble.
Now Playing: Science for the People

#529 Do You Really Want to Find Out Who's Your Daddy?
At least some of you by now have probably spit into a tube and mailed it off to find out who your closest relatives are, where you might be from, and what terrible diseases might await you. But what exactly did you find out? And what did you give away? In this live panel at Awesome Con we bring in science writer Tina Saey to talk about all her DNA testing, and bioethicist Debra Mathews, to determine whether Tina should have done it at all. Related links: What FamilyTreeDNA sharing genetic data with police means for you Crime solvers embraced...