USC study shows gene that may prevent cancer


Researchers at the Department of Molecular Microbiology and Immunology at the Keck School of Medicine of USC have discovered that the UV radiation Resistance Associated Gene could help prevent the onset of the skin cancer melanoma in high-risk individuals in a study that was conducted earlier this month. Lead researcher and associate professor Chengyu Liang and her team published their findings in Molecular Cell on May 19 during Melanoma/Skin Cancer Detection and Prevention Month.

The study found that UVRAG is heavily involved in a cell’s repair process following exposure to UV radiation. Proteins scan for impaired DNA and tag the gene to repair lesions. The expression of this gene is also directly related to survival rates and the metastasis of the cancer.

“The higher the UVRAG, the better the survival rate, and the slower the tumor progression,” Liang said in an email to the Daily Trojan. “The UV-protecting function of UVRAG allows the cells to repair UV-induced DNA damage efficiently, reducing the UV-induced genetic instability, thereby protecting against skin cancer.”

The UVRAG gene was discovered almost 20 years ago, but until the study conducted by USC researchers, the biological pathway, expression and function of the gene was unknown.

The study found that individuals with mutated versions of the gene will be more susceptible to melanoma, which is the deadliest type of skin cancer, claiming the lives of 10,130 people annually, according to the American Cancer Society.

“Without UVRAG or when UVRAG is reduced, the core machinery involved in damage repair cannot assemble efficiently, instead rather idle apart, leaving many damage unfixed,” Liang said. “Accumulation of such unfixed DNA errors increases the genetic instability, highly increasing the risk of melanoma and other skin cancer.”

The study compared the repaired damage of the normal UVRAG to mutated versions in melanoma cells and 50 fly eyes. After injecting the cells with UV radiation, they discovered that the normal gene repaired approximately twice as much damage as the mutated gene.

USC researchers also collaborated with the Children’s Hospital Los Angeles, the Korea Advanced Institute of Science and Technology and the Chinese Academy of Sciences in Beijing. The study was funded by The Margaret Early Trustee Foundation, American Cancer Society, National Institutes of Health Grants and GRL Program from the National Research Foundation of Korea.

This study provides a starting point for future drugs that could stimulate the repair mechanism of the gene for those who are at a high risk for melanoma. Liang says it can also be a helpful indicator for preventative measures.

“In the age of precision medicine, doctors may suggest their patients who have risks of skin cancer (such as skin cancer family history, super sensitive to sunlight, etc.) to screen this sunscreen gene and suggest those who have reduced levels of UVRAG or mutant version to protect more against sun exposure, such as lathering on more sunscreen with higher SPF and cover up more in summer, reducing outdoor activities in straight sunlight for long time, etc.,” Liang said.