Researchers have developed nanosensors that can detect signs of cancer in blood.Credit: Maskot/Getty
Researchers have developed a simple blood test to detect pancreatic cancer before it spreads to other sites in the body. The test could be used for routine screening to improve the disease’s low survival rate1.
“It’s a very pragmatic, really translatable solution,” that builds on many advances in the field, says Simone Schürle-Finke, a biomedical engineer at Swiss Federal Institute of Technology (ETH) in Zurich, Switzerland. The results are described in Science Translational Medicine today.
Most pancreatic cancers begin in the ducts that secrete enzymes used to digest food. But this form of cancer often doesn’t cause recognizable symptoms and isn’t detectable until it has metastasized and spread, making it difficult to treat. In 2022, some 467,000 died of the disease globally. “There is a huge need for developing new ways of detecting pancreatic cancer early,” says study co-author Jared Fischer, a molecular biologist at Oregon Health & Science University (OHSU) in Portland.
Telltale proteins
Fischer and his colleagues focused on detecting enzymes called proteases, which break down proteins and are active in tumours, even from the very early stages. They specifically looked at the activity of matrix metalloproteinases involved in chewing up collagen and the extracellular matrix, which helps tumours to invade the body.
To detect the presence of these proteases in the blood, the researchers developed nanosensors containing a magnetic nanoparticle, attached to a small peptide that attracts matrix metalloproteinases and a fluorescent molecule. They then placed millions of nanosensors in a tiny sample of blood. If matrix metalloproteinases were present, and active, they would chop the peptide in the nano-sensors, releasing the fluorescent molecule. The researchers then used a magnet to suck out all the unchopped nanosensors, and measure how many chopped fluorescent particles were left. The more active proteases were present in the blood, the brighter the sample was.
The researchers tested the nanosensor on frozen blood samples from 356 individuals, some with pancreatic cancer, some with non-cancerous forms of pancreatic disease and healthy controls. The nanosensor correctly identified healthy individuals 98% of the time, and identified people with pancreatic cancer with a 73% accuracy. It always distinguished between individuals with cancer from those with other pancreatic diseases.
Given that proteases are important for many bodily functions, Schürle-Finke did not expect the nanosensor to identify such a clear tumour signal in the blood. “I was really surprised to see that,” she says. The 73% sensitivity needs to be pushed higher before the sensors can be used by physicians, but overall, it is “a very promising, very impressive result”.
