Researchers from the National University of Singapore (NUS) have developed a new cancer testing method that makes regular monitoring more affordable.
The new test, dubbed the Heatrich-BS assay, heats the clinical samples to isolate cancer-specific signatures found in a patient’s blood.
The research team discovered the new method, which discards the non-informative sections of a patient’s DNA and targets where most cancer-specific biomarkers are concentrated instead.
DNA is comprised of molecules called nucleotides: namely adenine (A), thymine (T), guanine (G) and cytosine (C).
NUS said that cancer-specific signatures tend to be concentrated in genome areas that have high repetitions of C and G nucleotides, known as CpG islands.
NUS assistant professor Cheow Lih Feng said: “We were performing some unrelated experiments, and one of our researchers heated a sample.”
He said that the team accidentally discovered that the heat destroyed the non-informative sections of the genome, however, it left CpG island largely intact.
This helped the team to sequence the residual genome and identify the presence of cancer for a minute fraction of the average market price.
Cheow added: “We are getting a much more sensitive assay at almost the same costs as compared to simple protein biomarker tests. Our method really concentrates on sequencing these regions that matter the most.”
The new Heatrich-BS assay has been evaluated at the National Cancer Centre in Singapore, where it was used to monitor colorectal cancer patients.
The researchers’ team compared the results of the patients’ blood analysis with their CT scans, which showed the patients’ tumour size.
They found a high correlation between the size of the patient’s tumours over time and how much cancer-specific DNA was detected in their blood sample.
Cheow also said that the new method can work globally across all cancer types, as they all demonstrate the property of enriching CpG islands with biomarkers that are cancer-specific.