A quick, inexpensive but sensitive technique to detect cancer markers is bringing researchers nearer a “liquid biopsy”—a test utilizing a sample of blood or serum to detect cancer, rather than the invasive tissue sampling often used for diagnosis.
Researchers at the University of Illinois found a technique to capture and count cancer-linked microRNAs or tiny pieces of messenger molecules that are exuded from cells and can be detected in blood or serum, with a single-molecule resolution. The group revealed its conclusions in the Proceedings of the National Academy of Sciences.
Cunningham’s group developed a technique called Photonic Resonator Absorption Microscopy to seize and count microRNA biomarkers. In partnership with professor Manish Kohli at the Moffitt cancers facility in Florida, they tested PRAM on two microRNAs, which are recognized markers for prostate cancer.
They discovered it was delicate enough to detect small amounts that may be present in an affected person’s serum, but also selective sufficient to identify the marker among a mix of molecules that additionally could be present in plasma.
PRAM achieves both qualities by integrating a molecular probe and a photonic crystal sensor. The probe very specifically couples to a delegated microRNA and has a cap that comes off when it finds and attaches to the target biomarker. The open end of the probe can then connect to the sensor, creating a signal noticed through a microscope.
The PRAM approach may very well be adapted to different microRNAs or other biomarkers, the researchers say, and is suitable with existing microscope platforms.