Researchers from MIT and Harvard have used CRISPR to develop a diagnostic tool that detects cancer from urine samples, their work has been published in biorxiv. Cancer patients may be able to use this diagnostic tool at home in the future to monitor their disease severity. The researchers took advantage of the differences between the cancerous and normal tissues to develop this diagnostic tool, as several proteases are highly expressed in colorectal tumour tissue compared to healthy tissue. These proteases belong to serine protease families, matrix metalloproteinase, and aspartic families.
So, how does it work?
Firstly, the DNA barcoded synthetic biomarker is developed, it contains a specific protease substrate and DNA barcode. This DNA barcoded synthetic biomarker is injected into the body and then when the disease-specific proteases bind to the complex, the DNA barcode is released. These barcodes will concentrate in the urine and can be collected for further analysis. Then CRISPR-Cas technology (specifically Cas12a) is used to decode the barcodes as Cas12a activates reporter signals by cleaving them and the abundance of these signals can be interpreted either by fluorescence kinetics or on a lateral flow paper strip (POC device). The summary for this tool can be observed in the image below.
"In murine cancer models, we show that the DNA-encoded urine biomarkers can noninvasively detect and monitor disease progression, and demonstrate that nuclease amplification can be harnessed to convert the readout to a point-of-care tool. This technique combines specificity with ease of use to offer a new platform to study human disease and guide therapeutic decisions." said the researchers in the publication.
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