Study Finds Expression of miR-21 Can Predict Biochemical Failure in Prostate Cancer Patients

Study Finds Expression of miR-21 Can Predict Biochemical Failure in Prostate Cancer Patients

shutterstock_150591119In a recent study titled “Stromal Expression of MiR-21 Predicts Biochemical Failure in Prostate Cancer Patients with Gleason Score 6”, published in PlosOne, a group of researchers from the University Hospital of North Norway, saw that high stromal expression of miR-21 was related to poor biochemical recurrence-free survival after radical prostatectomy (RP) in prostate cancer patients.

MicroRNAs are responsible for regulating protein expression and their role in prostate cancer, along with many other neoplastic diseases, is the subject of several ongoing studies.

The research team, led by Dr. Elin Richardsen, wanted to explore the miRNA profile in prostate cancer tissue, to understand the link with clinicopathologic data and study the potential of using miRNAs as diagnostic and prognostic markers of disease.

From a total of 535 patients who underwent RP, 30 patients (14 with rapid biochemical failure (BF) and 16 without), were analyzed. Using microarray hybridization, the team quantified 1435 miRNAs, selecting those with the highest standard deviation to be validated by real time polymerase chain reaction (PCR). Furthermore, expression of miR-21 was assessed using in situ hybridization.

Researchers found that in the BF group, miR-21 was the only miR that was significantly upregulated. Furthermore, high expression of miR-21 was a predictor of biochemical failure-free survival (BFFS) and clinical failure-free survival.

Additionally, in men with Gleason score 6 (a systemused to help evaluate the prognosis of patients with prostate cancer) high expression of miR-21 was an independent prognostic factor for BFFS.

These results show that the level of stromal miR-21 expression could be a potential tool to predict which types of prostate tumors are more likely to progress. It is known that only a minority of patients diagnosed with a Gleason score lower than 6 will actually progress independently of treatment. However, a significant percentage of these patients will continue to receive unnecessary treatment after a diagnosis of low risk prostate cancer.

As the authors state in their publication, “our study is somewhat limited by the low number of cases with clinical relapse (…) Further studies of this microRNA and its associated pathways may uncover new mechanisms for cancer progression and therapeutic intervention”.