Researchers have created a cancer screening process that works like a pregnancy test.
Cancer deaths in third world countries now make up 70 percent of cancer deaths on the globe. Early detection is one of the best weapons against cancer mortality, but procedures such as mammograms and colonoscopies are too expensive to be widely used in the developing world, an MIT news release reported.
The urine-based test that employs only a small strip of paper could reveal in minutes if a patient has cancer.
The method detects biomarkers that are released by "nanoparticles that interact with tumor proteins called proteases," the news release reported.
"When we invented this new class of synthetic biomarker, we used a highly specialized instrument to do the analysis," Howard Hughes Medical Institute investigator Sangeeta Bhatia, said in the news release. "For the developing world, we thought it would be exciting to adapt it instead to a paper test that could be performed on unprocessed samples in a rural setting, without the need for any specialized equipment. The simple readout could even be transmitted to a remote caregiver by a picture on a mobile phone."
The tumor proteins, called matrix metalloproteinases (MMPs) help cancer cells spread by cutting them out of the extracellular matrix which holds them in place. The nanoparticles are covered with peptides ("short protein fragments") which MMPs target.
"These particles congregate at tumor sites, where MMPs cleave hundreds of peptides, which accumulate in the kidneys and are excreted in the urine," the news release reported.
These peptids can be detected using a mass spectrometer, but this is also too expensive for widespread use in developing countries. The team worked out a way to detect the particles using "lateral flow
The team coated the paper in "nitrocellulose paper with antibodies that can capture the peptides," the news release reported. The peptides are captured and flow along the strip into test lines made from "antibodies specific to different tags attached to the peptides." If one of these invisible test lines becomes visible it means a peptide has been detected.
"This is a clever and inspired technology to develop new exogenous compounds that can detect clinical conditions with aberrantly high protease concentrations," Samuel Sia, an associate professor of biological engineering at Columbia University who was not involved in the research, said in the news release. "Extending this technology to detection by strip tests is a big leap forward in bringing its use to outpatient clinics and decentralized health settings."
The new technique would be used for high-risk people at first; but the researchers hope it will soon spread across the globe.
