miRNAs, Could Be a Reliable Biomarker of Endometriosis

miRNAs could be a reliable biomarker to diagnose, follow the progression, and monitor the response to treatment of endometriosis, new study finds.

Key Points

Highlights:

• miRNAs (micro RNAs) are small pieces of genetic material that do not code for a protein, thought to regulate gene expression. Some miRNAs are dysregulated in endometriosis. 
• The levels of two miRNAs decrease while that of one miRNA increases in response to simvastatin treatment in the blood of baboons with endometriosis. These are the exact same miRNA that are too high or too low in the blood of women with endometriosis.  

Importance:

• Measuring the level of certain miRNAs in the blood could be a great new way to monitor the progression of endometriosis in a less invasive manner, also to measure the disease response to treatment.

What's done here:

• Researchers induced endometriosis in baboons by laparoscopy and then treated half of the animals with simvastatin for three months.
• They then evaluated the disease in all the animals and looked at the levels of nine different miRNAs in their blood.

Key results:

• The levels of miR-150-5p and miR-451a were decreased in the blood of baboons treated with simvastatin compared to those who were untreated.
• The level of miR-3613-5p was increased in the blood of treated baboons.
• Simvastatin treatment reduced the volume of endometriosis lesions in the baboons as previously reported.

Limitations:

• The findings reported in this study were obtained using an animal model. More research is needed before blood miRNA levels can be used in the clinic as a way to understand how well patients with endometriosis respond to a certain treatment.
• The exact role and the functional importance is not clarified. Other inflammatory conditions that may induce a change in these mRNAs are not examined.

Lay Summary

miRNAs, small pieces of genetic material found in the blood could be used as a reliable marker to diagnose endometriosis, according to a study by U.S. researchers. They could also be used to follow the progression of the disease and measure how well it responds to treatment.

Being able to monitor the natural behavior of endometriosis and to understand how well a certain therapy works, are of great importance to improve patient care. This research shows that serum miRNAs could be used as an objective measure of endometriosis in a less-invasive manner.

miRNAs or micro RNAs are small pieces of genetic material that do not code for a protein. They are thought to regulate gene expression, or how much protein will be made from a certain gene. Some miRNAs are known to be dysregulated in endometriosis. 

For the present study that was published in the scientific journal Reproductive Sciences, researchers led by Dr. Hugh Taylor at Yale School of Medicine analyzed the expression of miRNAs in the blood of a non-human primate model of endometriosis. Their aim was to understand whether these miRNAs could be used as a biomarker to follow the progression of the disease and the way it responds to treatment. 

The researchers induced endometriosis in 16 baboons by laparoscopy. They then divided the animals into two groups. They treated those in the first group with simvastatin for three months, while they left those in the second group untreated. Simvastatin is a medication used to lower cholesterol. It is also thought to be potentially beneficial in women with endometriosis who do not respond well to hormonal treatment. 

At the end of the three-month period, the researchers evaluated endometriosis in the baboons by laparoscopy. They also looked at the levels of nine different miRNAs circulating in their blood, focusing on the ones that are known to be dysregulated in endometriosis.

They found that simvastatin treatment led to a significant decrease in the volume of endometriosis lesions. They published these findings in a separate report. 

In the current study, they reported that the levels of two miRNAs (called miR-150-5p and miR-451a) were decreased in the blood of baboons treated with simvastatin, while the levels of another miRNA, miR-3613-5p was increased.

These were the exact same miRNAs that the researchers found to be increased or decreased in the blood of women with endometriosis, with miR-150-5p and miR-451a being too high and miR-3613-5p being too low. In other words, simvastatin treatment helped levels of these three miRNAs return towards normal levels. These findings support the importance of these particular miRNAs in endometriosis.

“This is the first report showing serum miRNA expression normalized in response to endometriosis treatment,” the researchers wrote. They added that further research will help optimize the clinical utility of specific miRNAs to monitor and treat endometriosis.  

Research Source: https://www.ncbi.nlm.nih.gov/pubmed/29587611