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Biomarker Test Offers Hope For Early Detection Of Pancreatic Cancer

Published: Friday, February 17, 2017 - 11:56am
Updated: Friday, February 17, 2017 - 3:05pm
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(Photo by Fei Lu, Department of Nanomedicine, Houston Methodist Research Institute)
The test uses two gold nanoparticles to detect cancer-linked EVs: A nanosphere, which refracts green light, and a nanorod, which refracts red light. When a match is found, the two interact, shifting the wavelength to a bright yellow.

Pancreatic cancer is the fourth leading cause of cancer deaths in the United States each year, in part because around four-fifths of cases go undetected until they have reached an advanced stage.

But a new test could soon change all that — and offer a way to monitor treatment outcomes as well.

"It’s pretty hard to say how early you can identify it. But, right now, we show the potential to differentiate Stage I pancreatic cancer patients from pancreatitis patients, and I think that’s a step forward,” said Tony Hu, an associate professor at the Biodesign Institute, who worked on the study.

Houston Methodist Research Institute, the Chinese Academy of Sciences Institute of Biophysics, University of Texas M.D. Anderson Cancer Center and the National Institutes of Health also contributed to the research, which was published in the Feb. 6 edition of Nature Biomedical Engineering.

Even while pancreatic cancer flies under the radar symptom-wise, its cells drop medical breadcrumbs, or biomarkers, in the blood. These small, fluid-filled sacs are called extracellular vesicles (EVs). Since all cells can shed EVs, the trick lies in efficiently isolating the cancer-linked ones from the rest.

“There are a lot of commercialized kits for EV isolation, but they are all, they all capture the general EVs. They cannot differentiate,” said Hu.

The new test uses two virus-sized nanoparticles to detect cancer-linked EVs amid the countless blobs shed by other cells. One, a gold nanosphere, refracts green light; the other, a gold nanorod, refracts red light. When a match is found, the two interact, shifting the wavelength to a bright yellow.

“Based on this color change and the intensity, we can identify the tumor-derived exosome,” said Hu.

Hu said that the method could work for other diseases, too.

“Based on the principle of this method, we can easily change the antibody on the nanoparticles, and then serve for the diagnosis of other diseases.”

Hu said that the next steps will involve validating the method using larger cohorts and making the technology more portable, for clinical or point-of-care use.