Researchers in Spain published a new report describing their search for myotonic dystrophy (DM1) biomarkers. Unfortunately, the search for miRNAs that could help identify the disease was not successful.
The report, “Six Serum miRNAs Fail to Validate as Myotonic Dystrophy Type 1 Biomarkers,“ appeared in the journal Public Library of Science One.
Myotonic dystrophy is a genetic disease caused by changes in the DMPK gene. Symptoms include muscular, heart, and psychological problems. However, there is a great deal of unpredictability in the severity of the disease, as well as in specific symptoms in individual patients. It is difficult to know how quickly the disease will progress in any patient. Biomarkers that can help predict the progression of the disease and help identify subsets of patients might also help in the selection of treatments individually tailored to patients.
Micro RNAs (miRNA) function to shut off other genes and may act in diseases such as myotonic dystrophy. Previous studies have revealed that miRNAs found in muscle samples and body fluid might act as biomarkers for myotonic dystrophy.
Led by Juan M. Fernandez-Costa of the Translational Genomics Group at Incliva Health Research Institute in Valencia, Spain, the team set out to identify new biomarkers for myotonic dystrophy that could identify subsets of patients with the disease. Previous studies indicated that specific miRNAs may vary in the heart and muscle tissues of people with myotonic dystrophy. The scientists therefore “profiled the expression of 175 known serum miRNAs in myotonic dystrophy samples.”
They found a less than 2.6-fold difference between miRNAs in people with myotonic dystrophy compared to a control group of individuals without myotonic dystrophy. Focusing on six specific candidate miRNAs, including, miR-103, miR-107, miR-21, miR-29a, miR-30c, and miR-652, they were unable to identify consistent differences that could define any of the miRNAs as a biomarker.
“Under our reported conditions, the miRNAs miR-103, miR-107,miR-21, miR-29a, miR-30c, and miR-652 are not useful serum biomarkers for myotonic dystrophy,” the investigators concluded. “Although the successful use of miRNAs from body fluids as disease-severity and progression biomarkers in other studies represents an encouraging advance, several technical aspects must first be standardized because methodological differences in the experimental procedures seem to be the main reason that data from different studies do not coincide.”
More research is needed to determine whether miRNAs can be used as biomarkers for myotonic dystrophy, although the current study does not indicate that the approach is promising. This could be due to differences in the methods used in different labs, or it may be that molecules other than miRNAs may serve as better biomarkers for this disease.