Accurate quantification of human miRNA isoforms using the PROMER technology

MicroRNAs (miRNAs) are short, non-coding RNAs that regulate gene expression at the post-transcriptional level, typically through sequence-specific interactions with the 3' untranslated regions (3' UTRs) of target mRNAs. It is increasingly recognized that individual miRNA loci can generate multiple sequence variants, known as isomiRs, which may differ at the 5' or 3' ends of the mature miRNA sequence. Differential expression of isomiRs has been observed across developmental stages and in various pathological conditions, including cancer, cardiovascular diseases, and neurological disorders. These findings underscore the importance of considering isomiR diversity in studies of miRNA function and in the development of miRNA-based diagnostics and therapeutics. We have previously reported the PROMER technology, which measures various miRNAs by relying on RNA:DNA perfect matching in the primer-template interaction, followed by RNase H2 cleavage to generate a 3'-hydroxyl group for new DNA synthesis. Here, we further developed a qRT-PCR-based innovative technique building on this PROMER technology to distinguish various isomiRs.