Lung Carcinogenesis Tracked By DNA Methylation In Breath

Dr. Simon Spivack and Dr. Weiguo Han from the New York State Department of Health are planning to present research showing the feasibility of testing DNA within condensed breath.
From the statement by the American Association for Cancer Research:

For the first time, researchers have demonstrated that it is possible to detect DNA methylation in the breath of smokers and lung cancer patients, suggesting that, in theory, it may be possible to use this technique to identify people who have undiagnosed lung cancer or are at high risk of developing the disease.
Investigators at the Wadsworth Center, the public health laboratory of the New York State Department of Health, have been able to develop an assay that simultaneously detects the presence of methylation in six tumor suppressor genes – a process by which a gene is chemically silenced. The assay examines the promoter region of a gene, where certain cytosine nucleotide bases may be methylated, preventing the gene from being expressed.
The seven participants tested so far breathe for ten minutes into a commercially available handheld device, which cools the air, forming a condensed vapor, to which the methylation assay is applied. Investigators found it could detect the presence of the methylated form in all six tumor suppressor genes. For RASSF1A, the test was negative in non-smokers, and positive in both current and ex-smokers. For DAPK, methylation was more variable, given smoking status. The four other tested genes (p16, MGMT, PAX5B,CDH1) known to be methylated in various stages of lung cancer development, were minimally or not methylated, in this pilot study of predominantly cancer-free smokers.
“Dr. Weiguo Han and I have shown that this approach is technically feasible, and if further research demonstrates the assay can measure DNA in such a way that it diagnoses or predicts lung cancer, this could be important for non-invasive lung cancer testing,” said the study’s lead author, Simon D. Spivack, M.D., M.P.H., a research physician at the Wadsworth Center, and a specialist in lung diseases. “But we are a long way from that point.” Han, a post-doctoral fellow in Spivacks’ laboratory and the study’s first author, will be presenting the findings.
Spivack said his study was only the third to date that proved DNA could be tested in condensed breath – German researchers reported the first such result in 2003, followed by an Italian group in 2005 – and the first to find methylation-silenced tumor suppressor genes in the breath of patients at risk or harboring lung cancer.

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