Sun and skin.We’ve known for quite a while that putting the two together can be a problem.
Ultraviolet radiation from the sun is the primary factor in the development of the vast majority of skin cancers.
What isn’t clear, though, is the sequence of events leading from sun exposure to the development of a tumour. “If we understood exactly the molecular mechanisms of skin cancer, then we might be able to design novel ways to prevent and even cure skin cancer,” says Dr. Victor Tron, Chair of the Department of Laboratory Medicine and Pathology at the University of Alberta.
Dr. Tron’s research focuses on the genes involved in the development of skin cancer.
“Ultraviolet radiation damages our DNA by altering the bonds that hold DNA together,” he explains. “But why is it that not everyone who is exposed to the sun gets skin cancer? We think it’s due mainly to a protein called p53.”
Called a tumour suppressor gene, p53 is responsible for the body’s ability to recognize cells that have been exposed to too much ultraviolet radiation. It can direct the repair of DNA, or even get rid of damaged cells by killing them. But UV radiation can also damage the DNA in the gene that codes for p53. As a result, the p53 protein doesn’t repair mutated cells as it should, and they end up dividing and propagating. A tumour is born.
“In our studies, we found mutated p53 in the very earliest stages of skin cancer,” says Dr. Tron. “We’re confident that p53 is controlling the process, but we don’t yet know whether it does this directly or through a series of steps which involve other molecules.
“This is becoming a very tangled web, but that’s the essence of science. The more answers you get, the more questions there are.
“I love the research. Honestly, it’s just like Christmas when someone shows me an interesting result. It’s that exciting.”
Currently, Dr. Tron’s research team is studying three molecules that depend on p53 to become active. This summer, three students (two of them funded by AHFMR) are exploring the regulation of the DNA repair process. It’s possible that one of the molecules could become a target for a new therapy. For example, a topical cream could be developed that enhances the expression of a particular molecule. This would in turn enhance the process of DNA repair.
Dr. Tron notes that such a therapy would not be limited to the treatment of skin cancer. “We may also be able to treat photo-aging–damage done to the skin due to the direct effects of ultraviolet light,” he says. “Some older patients tend to have leathery skin that often sags or droops. Wrinkles are another major cosmetic concern, and the cause of wrinkling can often be traced back to sun exposure. By and large, current treatments for wrinkles are not science-based.”
However, don’t expect “Dr. Tron’s Anti-Wrinkle/ Anti-Cancer Cream” to appear on drugstore shelves soon. “Our goal is to gain a firm understanding of how the body’s ability to prevent skin cancer becomes compromised,” explains Dr. Tron. “Only then will we be able to develop effective treatments.”
Dr. Victor Tron holds an AHFMR Independent Establishment Grant and is Professor and Chair of the Department of Laboratory Medicine and Pathology at the University of Alberta. He also receives support from the Canadian Institutes of Health Research, formerly the Medical Research Council of Canada, and the National Cancer Institute of Canada.