Just in time for Skin Cancer Detection and Prevention Month, a new University of Southern California (USC) study has discovered a "sunscreen" gene that might help protect against skin cancer, revealing that the unique gene acts as a tumor suppressor for skin cancer.
"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 of USC and senior author of the study.
Over 90 percent of melanoma skin cancers stem from cell damage caused by ultraviolet radiation. The American Cancer society reports that melanoma kills approximately 10,130 people each year.
"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."
The team used data from 340 melanoma patients from The Cancer Genome Atlas, as well as two experimental groups that possessed either reduced levels of the UV-resistant sunscreen gene or a mutant copy of it in melanoma cells and 50 fly eyes; melanoma cells or fly eyes with normal copies of the sunscreen gene acted as the control groups.
After administering a UV shot to cells with the normal sunscreen gene and those carrying defective copies, the team waited for 24 hours before further examination. Subsequent analysis revealed that cells carrying normal versions of the gene had repaired over 50 percent of the UV-induced damage, whereas defective samples repaired less than 20 percent of the UV-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."
In addition, the USC team found a correlation with increased cancer risk, although there is not yet any definitive evidence that lower levels or mutant copies of the sunscreen gene are directly connected to skin cancer development.
The findings were published in the May 19 issue of the journal Molecular Cell.