Blood MicroRNA Levels May Help Diagnose MPM and Asbestosis, Pilot Study Finds

Researchers have found that patients with malignant pleural mesothelioma (MPM) and asbestosis — a chronic lung disease caused by asbestos inhalation — have low levels of certain microRNAs (miRNAs) in blood and tissue samples, indicating that such miRNAs could be used as biomarkers to diagnose these diseases.

miRNAs are small RNA molecules that do not code for any protein, but regulate the production of specific proteins in the body. Higher levels of miRNAs were associated with longer survival in patients with MPM.

The study, “MicroRNA Expression in Malignant Pleural Mesothelioma and Asbestosis: A Pilot Study,” was published online in the journal Disease Markers.

Because the silent progression of MPM often leads to a very late diagnosis, researchers have been looking for biomarkers that could detect the presence of malignant cells in the mesothelium in the earlier stages of the disease, when chances of survival are higher.

miRNAs are known to play an important role in the development of a multitude of diseases, and studies have implicated a variety of miRNAs in the pathogenesis and development of MPM. Researchers at the University of Parma, in Italy, examined the levels of four miRNAs — miRNA-16, miRNA-17, miRNA-126, and miRNA-486 — in blood and tissue samples from MPM and asbestosis patients.

The study included 32 subjects with MPM who were awaiting surgery, 14 subjects with asbestosis, and  each was compared to 15 subjects with other noncancerous pulmonary diseases who were used as controls.

The levels of all four miRNAs were lower in the blood of MPM and asbestosis patients than in the control subjects, indicating they may help diagnose diseases caused by exposure to asbestos.

In addition, the team found that the levels of certain miRNAs correlated with survival outcomes in MPM patients. Indeed, the higher the levels of miRNA-16 in blood and tissue samples, and of miRNA-486 in tissue samples only, the longer the survival time. The authors propose that measures of miRNA levels could be used to monitor MPM disease progression during therapy.

Based on their results, the researchers propose that miRNA-486 be used either in the diagnosis of asbestosis, or as a target in MPM therapy. In general, they consider that the miRNAs they studied actually may be part of the cause of mesothelioma and asbestosis, making them promising targets for therapy.

“Although the sample size used in the study was small, the noninvasive characteristics of plasma sampling lead us to hypothesize that these biomarkers could be used alongside traditional imaging techniques in clinical practice and may help in the early diagnosis of MPM. The available data clearly support the role of miRNAs in the etiology of mesothelioma and asbestosis suggesting their possible use as diagnostic/prognostic markers of disease,” the study concluded.

“Considering that miRNAs are the underlying mechanism in the development of human disease, regulation of miRNA function may have therapeutic utility. miRNA-based therapeutics is an attractive research area and is a promising field to improve the treatment of cancers like MPM and other diseases,” the researchers added.