Sensor Created To Detect Metastatic Cancers In Tissue
Connie K. Ho for redOrbit.com — Your Universe Online
Chemists from the University of Massachusetts, Amherst (UMass) were recently able to create a sensor that works like the nose to “sniff” out and diagnose cancers.
In particular, the sensor is a quick and sensitive way of detecting metastatic cell types at various microscopic levels. The research is important in helping scientists understand metastatic cancers, which can spread among organs and tissues. The findings were recently featured in the journal ACS Nano.
“With this tool, we can now actually detect and identify metastasized tumor cells in living animal tissue rapidly and effectively using the ℠nose´ strategy. We were the first group to use this approach in cells, which is relatively straightforward. Now we´ve done it in tissues and organs, which are very much more complex. With this advance, we´re much closer to the promise of a general diagnostic test,” explained Vincent Rotello, a chemist at UMass, in a news release.
In the study, the researchers looked at a lung cancer metastasis model in mice that was pre-clinical and non-small-cell. They were able to “smell” out different cancer types with the help of a sensory array system developed by gold nanoparticles and proteins. The sensor was able to function similarly to how the human nose can determine odors and remember the smells. The team of investigators utilized a group of gold nanoparticle sensors with green fluorescent protein (GFP) that identified cancers by giving each a signature marking based off of a pattern of proteins found in cancer cells.
“Smell ℠A´ generates a pattern in the nose, a unique set of activated receptors, and these are different for every smell we encounter. Smell ℠B´ has a different pattern. Your brain will instantly recognize each, even if the only time you ever smelled it was 40 years ago. In the same way, we can tune or teach our nanoparticle array to recognize many healthy tissues, so it can immediately recognize something that´s even a little bit ℠off,´ that is, very subtly different from normal. It´s like a ℠check engine´ light, and assigns a different pattern to each ℠wrong´ tissue. The sensitivity is exquisite, and very powerful,” Rotello continued.
In the project, the scientists trained a nanoparticle-GFP sensor array to identify healthy tissue and mouse tumor samples. As such, they were able to differentiate between healthy tissue and metastasis efficiently. This provides a quick way of determining cancer and other disease with the help of micro-biopsies.
The research was based on past findings by Rotello and fellow scientists on a “chemical nose” of nanoparticles and polymers to distinguish between cancerous and normal cells. Previously, scientists identified cancer cells with a biological receptor method where a protein was attached to the wall of a cancer cell. However, a difficulty in this approach was recognizing the correct receptor prior to the experiment.
“It´s sensitive to really subtle differences,” remarked Rotello. “Even though two cheeses may look the same, our noses can tell a nicely ripe one from a cheese that´s a few days past tasting good. In the same way, once we train the sensor array we can identify whether a tissue sample is healthy or not and what kind of cancer it is with very high accuracy. The sensitivity is impressive from a sample of only about 2,000 cells, a microbiopsy that´s less invasive for patients.”
In future studies, the researchers plan to examine new sensor array methods in human tissue samples.
“Overall, this array-based sensing strategy presents the prospect of unbiased phenotype screening of tissue states arising from genetic variations and differentiation state,” concluded Rotello.