The study, published in Journal of Chromatography B, paves the way for a non-invasive odor analysis technique to be used in the detection and early diagnosis of the disease.
Melanoma is a tumor affecting melanocytes, skin cells that produce the dark pigment that gives skin its color. The disease is responsible for approximately 75 percent of skin cancer deaths, with chances of survival directly related to how early the cancer is detected.
Human skin produces airborne chemical molecules known as volatile organic compounds, or VOCs, many of which are odorous.
Through sophisticated sampling and analytical techniques, researchers identified VOCs from melanoma cells at three stages of growth as well as from normal melanocytes.
Melanoma cells produced certain compounds not detected in VOCs from normal melanocytes and also more or less of other chemicals. Further, the different types of melanoma cells could be distinguished from one another.
"There is a potential wealth of information waiting to be extracted from examination of VOCs associated with various diseases, including cancers, genetic disorders, and viral or bacterial infections," notes George Preti, PhD, an organic chemist at Monell who is one of the paper's senior authors.
To translate this discovery into a practical diagnostic tool, researchers used carbon nano-tube sensors coated with DNA, which can be bioengineered to recognize specific odor molecules.
"We are excited to see that the DNA-carbon nanotube vapor sensor concept has potential for use as a diagnostic. Our plan is to move forward with research into skin cancer and other diseases," said A.T. Charlie Johnson, PhD, Professor of Physics at the University of Pennsylvania, who led the development of the olfactory sensor.
"This study demonstrates the usefulness of examining VOCs from diseases for rapid and noninvasive diagnostic purposes," said Preti. "The methodology should also allow us to differentiate stages of the disease process."