Optical techniques could improve detection, diagnosis of metastatic melanomas

A team of researchers at the University of Missouri (MU; Columbia, MO) has developed an optical tool to better detect and analyze single melanoma cells that are more representative of the skin cancers developed by most patients, which are irregular and dark, making them difficult to investigate.

Related: Single-molecule imaging could get boost from nanoscale technology to study diseases

"Researchers often seek out the types of cancerous cells that are homogenous in nature and are easier to observe with traditional microscopic devices," says Luis Polo-Parada, an associate professor of medical pharmacology and physiology and an investigator at the Dalton Cardiovascular Research Center. "Yet, because the vast amount of research is conducted on one type of cell, it often can lead to misdiagnosis in a clinical setting."

The team that included Gary Baker, an assistant professor of chemistry in the MU College of Arts and Science, and Gerardo Gutierrez-Juarez, a professor and investigator at the University of Guanajuato in Mexico, decided to supplement an emerging technique called photoacoustic spectroscopy, a specialized optical technique that is used to probe tissues and cells noninvasively. Current systems use the formation of sound waves followed by the absorption of light, which means that the tissues must adequately absorb the laser light. This is why researchers have focused only on consistently hued and shaped melanoma cells, Polo-Parada says.

The team modified a microscope that was able to merge light sources at a range conducive to observing the details of single melanoma cells. Using the modified system, human melanoma and breast cancers as well as mouse melanoma cells were diagnosed with greater ease and efficiency. The team also noted that as the cancer cells divided, they grew paler in color but the system was able to detect the newer, smaller cells as well.

"Overall, our studies show that by using modified techniques we will be able to observe non-uniform cancer cells, regardless of their origin," Polo-Parada says. "Additionally, as these melanoma cells divide and distribute themselves throughout the blood, they can cause melanomas to metastasize. We were able to observe those cancers as well. This method could help medical doctors and pathologists to detect cancers as they spread, becoming one of the tools in the fight against this fatal disease."

Full details of the work appear in the journal Analyst; for more information, please visit http://dx.doi.org/10.1039/c6an02662a.