September 1, 2011

Cancer Risk Assessment: From Saliva?

Last week, we learned that researchers had generated brain cells (neurons) from skin cells of a Parkinson’s patient: a potential step forward in studying and treating the disease. This week, at a meeting of the American Chemical Society, researchers unveiled a new saliva test that measures potential carcinogens attached to a person’s DNA. This new test might soon be available commercially, and could help people assess their risk for cancer and other diseases, like Alzheimer’s.

Professor Hauh-Jyun Candy Chen, Ph.D., led the research team at National Chung Cheng University in Taiwan. She explained the process:

The test measures the amount of damaged DNA in a person’s body. This is very important because such damaged DNA — we call this ‘DNA adducts’ — is a biomarker that may help doctors diagnose diseases, monitor how effective a treatment is and also recommend things high-risk patients can do to reduce the chances of actually getting a disease. We tried urine and blood and found these adducts. Then we turned our attention to saliva. It’s much more convenient to collect a sample of saliva.
These “adducts” form when substances that might cause cancer chemically attach to DNA. We come into contact with these substances, like cigarette smoke, regularly. When the adducts attach to -- and then change -- DNA, our bodies’ natural ability to repair the damage can fail, which then leads to mutation, and – possibly – cancer. These potentially cancer-causing substances also collect on our DNA as a normal function of aging, and have been linked with other health problems, like Alzheimer’s.

This new test uses a sensitive mass spectrometer to evaluate the DNA adducts in saliva. In the past, DNA was collected from white cells in blood. Chen’s new test uses white cells found naturally in saliva, and from cells shed from the lining of the mouth: easier, faster, and less costly than blood-based testing.

Chen sees a variety of uses for the new test, which she thinks will cost several hundred dollars. For example, if cigarette smokers learn of significant accumulation of DNA adducts, they might be more encouraged to stop smoking. If follow-up tests reveal reduced levels, they may be encouraged to continue their healthier lifestyle choices (and, hopefully, NOT to start smoking again!).

1 comment:

Bill said...

Hello John, I know you are concerned about dementia, too.  There is a group -- Club Memory -- starting at Sibley on Sept 28th.  The purpose is to be a social organization for those with Alz, dementia, Parkinson's etc.  If you would like more info, see the Sibley webpage or contact me at