Researchers have uncovered a potentially important diagnostic tool in battling mesothelioma: DNA sequencing.

DNA affected by mesothelioma exhibits a distinct pattern after sequencing, which could make sequencing patients’ DNA strands an “effective tool” in diagnosing the deadly disease, according to a study published April 19 in the Journal of Molecular Diagnostics.

Normally, malignant pleural mesothelioma requires a battery of radiological tests, biopsies and blood work to correctly diagnose because its’ symptoms and presentation frequently mimic other conditions. However, a team of European researchers was able to distinguish the disease from other conditions by a lab technique known as methylation profiling.

The Goal Is Methylation

Methylation is a process in which a methane-based molecule bonds to a DNA strand. This happens all the time in normal cells and ensures the proper regulation of gene expression. But in cancer cells the process is corrupted, which can lead to mutation. It also seems to be the reason why cancer cells are able to fool the immune system into ignoring them, a process known as hypermethylation.

By running affected DNA strands through a sequencer, the researchers discovered that the methylation expressed by the DNA — known as its methylation profile — is distinctive for mesothelioma.

Comparative Testing

The researchers tested two sets of mesothelioma tissue samples — one set of 33 in the initial discovery and another 46 to later confirm their findings — against 202 tissue samples from a host of conditions that can easily be mistaken for mesothelioma. These include 20 samples of solitary fibrous tumors, 20 synovial sarcoma slides, 20 examples of leiomyosarcoma, 20 more of angiosarcoma, 10 tissue samples of nodular fasciitis, 10 desmoid-type fibromatosis slides, 20 examples of epithelioid sarcoma cells, 15 tissue samples of lung adenocarcinoma, 15 examples of lung squamous cell carcinoma, 20 melanoma samples, 12 reactive mesothelial hyperplasia slides and 10 sclerosing fibrous pleuritis cell samples.

In each case, the team was able to correctly distinguish the mesothelioma samples from these “mimics” via DNA sequencing results and statistical analysis tools.

“Methylation profiling proved to be an effective tool for the [malignant pleural mesothelioma] diagnostics, although caution is advised in samples with low tumor cell content,” the group reported.

The team includes researchers from the University of Turin in Italy, University Hospital of Heidelberg in Germany, and Radboud University Medical Center in the Netherlands.

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