Studying the Effect of Second- and Third-Hand Smoke on Cancer Risk in Golden Retrievers

THE PROBLEM: Many studies have documented the negative health outcomes in people associated with smoking or exposure to tobacco smoke. Some of these problems are the result of genetic changes including a phenomenon known as epigenetic alteration. Epigenetic alteration is a process where an individual’s DNA is altered not by damage or mutation, but by the addition of molecules to the DNA that alters function. There is data that exposure to tobacco smoke is associated with cancer in dogs and cats, but we don’t know the mechanisms underlying cancer development. If we understand the mechanism, we’re a step closer to prevention and treatment. 

THE PROJECT: In this project, researchers will look to see if a specific epigenetic change, the addition of a methyl group to DNA known as DNA methylation, is a possible mechanism for cancer development in dogs. The team will perform a variety of tests on blood samples from dogs in the Golden Retriever Lifetime Study. The samples used will come from dogs known to have exposure to tobacco smoke and those that have not. The researchers will measure DNA methylation in these samples and analyze the results. 

POTENTIAL IMPACT: If the team can find evidence for DNA methylation changes in dogs exposed to tobacco smoke, this could be a biomarker for cancer and could be used to assess risk. Monitoring DNA methylation also could be used as a measurement of the success, or failure, of prevention strategies. Ultimately, DNA methylation also could reveal new avenues for cancer screening and treatments.