A test to detect cancerous cells, which can be performed in ten minutes, is presented in Nature Communications this week. The assay exploits the differences between the DNA in cancerous and healthy cells to allow for a quick, initial diagnosis.
The attachment of methyl groups to DNA (in a process called methylation) is genetically programmed. In all ‘mature’ human cells, DNA carries these modifications. The genomic information in cancer cells is significantly different from healthy cells, resulting in a different methylation level and pattern in most types of cancer cells.
Matt Trau and colleagues found that the different methylation landscape in cancer cells affects the physical and chemical properties of DNA. Amongst other features, it binds more strongly to gold nanoparticles and the authors used this behaviour to develop a test to detect cancer. The assay requires a tiny amount of purified genomic DNA from a patient and takes about ten minutes. The outcome of the test can be assessed with the naked eye. They tested their approach on over 100 human samples (genomic DNA from patients with cancer (72) and healthy individuals (31)) representing various cancer types.
At this stage, the assay can only detect the presence of cancer cells, not their type or the stage of the disease. Moving forward, the approach needs further testing with more samples and - possibly - refinement to allow for a more detailed analysis.
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