MicroRNAs present in the blood show promise as potential minimally invasive biomarkers to help doctors distinguish between prostate cancer and benign prostatic hyperplasia (BPH), new research suggests.
The study, “Different Levels Of Serum MicroRNAs In Prostate Cancer And Benign Prostatic Hyperplasia: Evaluation Of Potential Diagnostic And Prognostic Role,” was published in the journal OncoTargets and Therapy.
Currents methods to diagnose prostate cancer include analysis of the levels of prostate specific antigen (PSA). However, this method may not be the most reliable, as PSA levels in the blood can increase both in cases of prostate cancer and BPH. Clinicians need to know which molecules are specific for each condition to better diagnose patients.
Researcher Ettore Mearini from the University of Perugia in Italy and his team decided to investigate whether prostate cancer and BPH had distinct signatures regarding a group of molecules called microRNAs, or miRs. These are small molecules that are able to bind to an mRNA molecule (a copy of the coding information for the production of a protein) and interfere with the production of that protein. One miR can bind to many different mRNA molecules, which makes microRNAs powerful regulators of gene expression.
The study enrolled 147 Caucasian age-matched patients with increased PSA levels who also underwent a prostate biopsy. Of the initial group, 68 patients were diagnosed with prostate cancer and 79 patients underwent transurethral prostate resection to confirm the diagnosis of BPH.
Researchers then collected blood samples from 64 prostate cancer and 60 BPH patients to investigate the levels of 21 different microRNAs that they had chosen to analyze, based on the possibility of these miRs to regulate several genes that have previously been associated with prostate cancer.
Results indicated that out of the 21 microRNAs analyzed, these were able to distinguish patients with prostate cancer from those with BPH: miRs let-7c, let-7e, let-7i; miR-26a-5p; miR-26b-5p; miR-18b-5p; and miR-25-3p.
Prostate cancer was specifically associated with the expression of miR-25-3p (highest sensitivity) and miR-18b-5p (highest specificity). The combination of these two microRNAs improved the overall sensitivity.
Also, miR-363-3p, miR-26a-5p, miR-26b-5p, miR-106a-5p, miR-18b-5p, miR-25-3p and miR-let-7i were found in decreased levels as disease malignancy increased.
“This study confirms serum miRNAs to be reliable candidates for the development of minimally invasive biomarkers for the diagnosis and prognosis of [prostate cancer], particularly in those cases where PSA acts as a flawed marker,” the authors concluded.