‘Sunscreen gene’ identified
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A study led by researchers from the University of Southern California's Keck School of Medicine in Los Angeles has identified a ‘sunscreen gene’ that appears to be protective against the development of melanoma.
Published in Molecular Cell (May 19, 2016; 62(4):507–519), the researchers call the gene ‘UV radiation resistance-associated gene’ (UVRAG). The gene had previously been isolated as a cDNA partially complementing UV sensitivity in xeroderma pigmentosum (XP) but research investigating a possible role in melanoma had not previously been performed, the authors note.
“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,” Dr. Chenyu Liang, the study’s senior author and an associate professor of molecular microbiology and immunology at the Keck School of Medicine of USC said in a press release.
Registry data, in vitro and in vivo models used
The study used data from 340 melanoma patients who participated in The Cancer Genome Atlas, as well as two experimental models–one with melanoma cells in vitro, and one fly-eye model.
In the two models, 24 hours after exposure to ultraviolet radiation, those cells in culture or in the fly eyes that had intact copies of UVRAG had repaired more than 50% of the UV-induced damage. The cells with a defective copy of the gene had repaired less than 20% 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,” Dr. 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.”
Gene expression correlates with improved survival
When they looked at the data from The Cancer Genome Atlas, the researchers found that level of expression of UVRAG was related to melanoma patients’ survival and metastasis stages.
“Lower levels of the UV-resistant gene means a lower survival rate and advanced metastases stages,” said Yongfei Yang, lead author and a research associate at Keck Medicine of USC.
The gene might represent a potential target for therapy, according to the press release. “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,” said Yang.