Comparing Cancer Genes Between Species Helps Prioritize Targets for New Cancer Treatments

Cancer genes in melanoma of the mucosa, a rare and poorly understood subtype of melanoma, have been compared for the first time in humans, dogs and horses by scientists from the institute Wellcome Sanger and their collaborators. The researchers sequenced the same cancer genomes in different species to identify key cancer genes.

The results, reported in Nature Communications, give an overview of the evolution of cancer in the tree of life and could guide the development of new treatments.

Mucous melanoma is a rare form of melanoma, a type of tumor usually badociated with skin cancer. Melanoma diagnosed annually in the UK about 15,400, about 1% of them will be diagnosed with mucosal melanoma.

Cancer occurs from pigment-producing cells, called melanocytes, which are found not only in the skin, but also in the body's mucous membranes, such as the sinuses, nasal pbadages, mouth, bad and l & # 39; anus.

Risk factors for mucosal melanoma are not known and there is no known connection with UV exposure or family history. Cancer patients often present with advanced disease. The main treatment of mucosal melanoma is the surgical removal of the tumor. In addition to humans, cancer affects dogs and horses with varying results for different species.

To discover the genetics underlying cancer, researchers at the Sanger Institute and their collaborators sequenced the genomes of mucosal melanoma tumors taken from human, canine and equine patients diagnosed with the disease.

By badyzing genomic data from 46 human melanoma, 65 canine and 28 equine tumors, all at the primary stage of cancer, scientists have revealed a handful of mutated genes in all species.

Dr. David Adams, corresponding author of the Wellcome Sanger Institute, said, "Genomics gives us a unique insight into the similarities and hidden differences between cancers between species." The genetic modifications, or mutations, we found in tumors of mucosal melanoma in humans, horses suggest that they are important enough to be conserved from one species to another.These key mutations are likely to cause cancer and could be targets for the development of new drugs. "

Immunotherapy, which stimulates the body's immune system to attack cancer cells, has been used to treat some people with melanoma, but has not been effective for people with the subtype, mucosal melanoma and the reason was unknown. Researchers now suggest that, unlike cutaneous melanoma, mucosal melanoma tumors carry few mutations, so that they remain "hidden" from the immune system and do not trigger the immune response needed to target cancer.

Kim Wong, lead author of the Wellcome Sanger Institute, said, "Understanding the genetic changes that underlie mucosal melanoma suggests why people with this type of cancer may not benefit from immunotherapies." Genomics can help identify people with cancer. those most exposed to development to provide information to genetic counselors and physicians advising patients on the management of the disease. "

This study is the first to sequence tumors in horses and the first genomic experiment of this scale on tumors in dogs. Gray horses are genetically predisposed to contracting melanoma. However, cancer is very different in horses because it does not usually spread, unlike the disease in humans and dogs.

Professor Geoffrey Wood, of the University of Guelph, Canada, said: "Spontaneous tumors in dogs are increasingly recognized as" models "of human cancers for the development of treatments that can benefit This study shows how important it is to understand genetic similarities and cancer differences between species, so as to prioritize the most biologically relevant drugs. "