Quantification of microRNA editing using two-tailed RT-qPCR for improved biomarker discovery

Area of Science:

• Molecular Biology
• Biochemistry
• Genomics

Background:

• MicroRNAs are promising biomarkers, but clinical use is limited by a lack of isoform-specific detection technologies.
• Adenosine deaminase acting on RNA (ADAR) enzymes introduce A-to-I edits in microRNAs, altering their function and expression.
• Commercially available assays cannot differentiate between edited and unedited microRNA isoforms.

Purpose of the Study:

• To develop and validate novel RT-qPCR assays capable of distinguishing between microRNA editing isoforms.
• To demonstrate the utility of these assays in detecting microRNA-379 (miR-379) editing isoforms in human tissues and cell lines.
• To investigate the clinical relevance of miR-379 editing in prostate cancer.

Main Methods:

• Development of two-tailed RT-qPCR assays specific for microRNA editing isoforms.
• Compatibility testing with SYBR Green and hydrolysis-based chemistries, and with qPCR and digital PCR.
• Application of assays to detect miR-379 editing in human tissues and ADAR-overexpressing cell lines.

Main Results:

• The developed RT-qPCR assays successfully differentiated between miR-379 editing isoforms.
• Higher miR-379 editing frequency was observed in prostate cancer samples compared to benign prostatic hyperplasia.
• Decreased expression of unedited miR-379 correlated with treatment resistance, metastasis, and poorer survival.

Conclusions:

• This study presents the first RT-qPCR assays for distinguishing A-to-I-edited microRNAs.
• These assays can identify previously masked microRNA biomarkers.
• The findings highlight the potential of miR-379 editing as a biomarker in prostate cancer and other diseases.