Small, non-coding bits of RNA in blood serum may offer a way to measure a person’s exposure to asbestos and predict their risk for mesothelioma.
Malignant mesothelioma is just one of several types of cancer linked to exposure to asbestos. But, unless a person knows they have been exposed, doctors might not even think to look for it, even when a patient develops early symptoms.
Researchers at Italy’s University of Ferrara have identified a microRNA in blood serum that can act as a biomarker for asbestos in the body. The discovery could lead to a blood test to identify high-risk people.
Exposure to Asbestos and Malignant Mesothelioma
Before asbestos, mesothelioma was virtually unheard of. In fact, when the first asbestos-exposed workers started getting sick in the 1930s and 1940s, doctors still had no name for this virulent membrane cancer.
Today, scientists know that exposure to asbestos is the number one risk factor for malignant mesothelioma. Once some of the dust gets into the body, either by inhalation or swallowing, the fibers work their way deep into the tissue. They can stay there indefinitely.
When a patient develops mesothelioma symptoms like cough, chest pain, and shortness of breath, the doctor may ask about their work history. It is sometimes possible to estimate how much asbestos a person was exposed to based on their industry, when they worked, and the number of hours they put in. The longer and heavier the exposure, the higher the risk for mesothelioma. But the only way to know for sure how much asbestos a person internalized is to look at their tissue under a microscope.
MicroRNAs May Hold the Key
MicroRNAs are single-strand, non-coding fragments of RNA. They help regulate the expression of key genes. The genes lead to the production of proteins that are responsible for nearly every cellular process.
Researchers at the University of Ferrara School of Medicine say one particular microRNA can help reveal a person’s level of asbestos exposure. Bits of this RNA, called microRNA-197-3p, circulate in the bloodstream. The team compared the level of miRNA-197-3p in the serum of healthy subjects and in workers who had exposure to asbestos.
“MicroRNA-197-3p was found to be 2.6 times down-regulated in workers exposed to asbestos vs. healthy subjects,” the researchers write in Scientific Reports.
The higher the person’s level of exposure to asbestos at work, the lower the level of microRNA-197-3p was in their blood. Workers with the highest levels of asbestos exposure had half as much microRNA-197-3p compared to those with less exposure.
The team concludes that microRNA-197-3p could be a powerful new potential biomarker of asbestos exposure. Testing for it could help doctors know which patients should be monitored for early signs of mesothelioma.
Approximately 2,500 Americans develop mesothelioma every year. Even though asbestos is the primary cause, the US government has failed to enact a ban.
Frontini, F, et al, “Circulating microRNA-197-3p as a potential biomarker for asbestos exposure”, December 14, 2021, Scientific Reports, https://www.nature.com/articles/s41598-021-03189-9