A new gene discovery may lead researchers to a treatment for eye cancer. Researchers at the University of California, San Diego, School of Medicine have discovered how two genetic mutations can cause the development of melanoma of the eye, which is the most common form of eye cancer. Figuring out how the genes work is only the first step in the battle to treat cancer. Researchers say now that they know, they have a promising therapeutic target for treating the disease in the future.
"The beauty of our study is its simplicity," said Kun-Liang Guan, PhD, co-author of the study and professor of pharmacology at UC San Diego Moores Cancer Center. "The genetics of this cancer are very simple and our results have clear implications for therapeutic treatments for the disease."
Guan and his colleagues revealed the relationship between the genetic mutations and tumor formation, in the journal Cancer Cell. They’ve also identified a molecular pathway for the drugs to work and attack cancer cells.
The two genes, GNAQ and GNA11, are codes for protein that function as an on and off switch that control the information from the outside to the inside of a cell. The researchers focused specifically on uveal melanoma because it occurs the most often for eye cancer. They’ve suspected for a long time that there was a genetic association with uveal melanoma because one of two gene mutations was present in approximately 70 percent of eye cancer diagnosis.
Intraocular melanoma of the eye occurs when cancer develops in the uvea, or middle layer of the eyeball. There are three parts that comprise the uvea, the iris, choroid, and ciliary body. They each play a significantly important role in helping us see: The iris is the colored part of the eye, the choroid is the thin pigmented layer lining and nourishing the eyeball, and the ciliary body is the muscular part inside the eye that changes shape as the lens focuses on a near or distant object.
Melanoma grows from the pigment-making cells called melanocytes. Eye cancer is considered a fairly uncommon form of cancer. Primary eye cancers can occur at any age, but the risk increases with age. The American Cancer Society estimates that in 2014 there will be 2,730 new cases of eye cancers, mostly of melanoma form in and around the eye. By the same estimate, 310 people will die from eye cancer by the end of this year.
Standard treatment for eye cancer is radiation and the surgical removal of the eye. Uveal melanoma often spreads to the liver, after which it can be more difficult to treat.
"We have a cancer that is caused by a very simple genetic mechanism," Guan said. "And we have a drug that works on this mechanism. The clinical applications are very direct."
Source: Guan K-L, Yu F, Luo J, et al. Mutant Gq/11 Promote Uveal Melanoma Tumorigenesis by Activating YAP. Cancer Cell, 2014.