MicroRNAs are small (between just 21 and 23 nucleotides), non-coding RNA molecules. They are involved in the post-transcriptional regulation of gene expression and are found throughout the bloodstream and the body’s cells.
In cancer cells, microRNAs can be damaged by mutations. As a result, microRNAs can be reduced to abnormally low levels, which can lead to overexpression of the genes regulated by the microRNAs. This, in turn, can lead to the development and progression of cancer.
In a recent study from the University of Galway, researchers assessed blood samples from 124 breast cancer patients to determine the quantity of microRNAs. They found that a particular microRNA called miR-145 was able to accurately predict the likelihood of recurrence for many patients.
Study co-author Dr. Matthew Davey says that “the process of identifying which patients are more likely to have a recurrence has been a challenge. Therefore we set out to determine whether miRNAs—small, non-coding molecules that modulate genetic expression and affect cancer development—are capable of predicting which patients are more likely to have a recurrence of, and die from, breast cancer.”
The researchers found that increased miR-145 expression correlated with better outcomes in early-stage breast cancer. In the future, miR-145, which can be collected from blood samples, could be used as a biomarker to predict breast cancer recurrence. miR-145 could also help identify patients who could benefit from additional therapies post-surgery or chemotherapy treatment.
Dr. Davey adds that “increased expression of this biomarker, which was measured in patients' blood samples during chemotherapy, actually predicted their long-term oncological outcome. We can predict those who are likely to suffer recurrence and also those who will be free of recurrence. Further studies into the clinical application of this biomarker are ongoing.”
Though further studies are needed to validate and repeat these results, the researchers are hopeful that miR-145 could be used as a diagnostic tool in the treatment of breast cancer.
Sources: Ohio State University, Journal of the American College of Surgeons
