MicroRNA Dynamics and Expression Profiling

MicroRNAs (miRNAs) are small, non-coding RNA molecules typically 20–24 nucleotides in length that regulate gene expression post-transcriptionally. Their biogenesis involves sequential processing steps from primary transcripts (pri-miRNAs) to precursor hairpins (pre-miRNAs) and finally to mature miRNAs incorporated into the RNA-induced silencing complex (RISC). Recent advances in high-throughput sequencing and computational analysis have revealed considerable heterogeneity at both the 5′ and 3′ ends of mature miRNAs, giving rise to sequence variants collectively termed isomiRs. These variants expand the regulatory repertoire of miRNAs by altering seed sequences, stability and target specificity. Expression-profiling studies now commonly employ small RNA sequencing combined with quantitative PCR validation to chart dynamic changes in miRNA and isomiR levels across development, disease states and environmental stimuli. Emerging network-based approaches further integrate co-expression and editing events to construct regulatory maps that elucidate how miRNA dynamics contribute to cellular processes such as proliferation, differentiation and stress responses. The interplay between genetic variation, post-transcriptional modifications and diverse biogenesis pathways underpins the complexity of the miRNA transcriptome and its impact on physiology and pathology.

Research from Nature Portfolio

Investigations into the functional impact of RNA editing on miRNA activity have highlighted the influence of adenosine-to-inosine (A-to-I) modifications. A study of miR-379 in prostate cancer cells compared the biological effects of unedited and A-to-I-edited isoforms. By transfecting isoform-specific mimics into androgen receptor-positive and ‑negative lines, researchers observed distinct roles for each variant in cell proliferation, migration and epithelial–mesenchymal transition markers. The unedited miR-379 suppressed growth in androgen-sensitive cells, whereas the edited form exhibited attenuated suppressive activity. In silico target prediction linked the unedited isoform to networks of cell cycle regulators, while the edited variant targeted a divergent set of transcripts. These findings demonstrate that A-to-I editing modulates the tumour-suppressive capacity of miRNAs and underscores the importance of isoform-specific profiling in cancer research.

Research from all publishers

Advances in network analysis have refined our understanding of miRNA-mediated regulation. A novel differential co-expression framework applied to prostate cancer datasets revealed that highly expressed isomiRs frequently lose their negative correlations with mRNA targets in tumour tissue, indicating disrupted post-transcriptional control. This approach identified cancer-specific isomiR–mRNA interactions, highlighting the potential of network perturbations as biomarkers. Complementary technical studies have addressed challenges in validating isomiR abundance by poly(A) RT-qPCR, showing that single-nucleotide differences between closely related variants can lead to cross-reactivity and quantification errors. Recommendations include prioritising canonical miRNAs with homogeneous isomiR expression patterns for robust assay design. Additionally, genetic studies have mapped cis-regulatory single-nucleotide polymorphisms in precursor miRNA regions to specific isomiR profiles, demonstrating that common variants shape isomiR biogenesis and contribute to differential expression patterns in cancer versus normal tissues. Together, these contributions advance the precision and interpretative power of miRNA profiling methodologies.

MicroRNA Dynamics and Expression Profiling publication trend

The graph below shows the total number of articles in microrna dynamics and expression profiling across all publications each year (not limited to Nature Index journals).

Technical terms

microRNA (miRNA): A small non-coding RNA that regulates gene expression by binding complementary sequences in target mRNAs.

isomiR: A sequence variant of a canonical miRNA arising from alternative cleavage or nucleotide modifications at the 5′ or 3′ ends.

A-to-I editing: A post-transcriptional modification in which adenosine is deaminated to inosine, altering base-pairing properties.

co-expression network analysis: A computational method to detect coordinated changes in expression between RNA species across conditions.

RT-qPCR: Reverse transcription quantitative polymerase chain reaction, a technique to quantify RNA levels by converting to cDNA and amplifying target sequences.

References

1. Functional consequences of A-to-I editing of miR-379 in prostate cancer cells. Scientific Reports (2023).
2. Differential co-expression network analysis with DCoNA reveals isomiR targeting aberrations in prostate cancer. Bioinformatics (2023).
3. 3′IsomiR Species Composition Affects Reliable Quantification of miRNA/isomiR Variants by Poly(A) RT-qPCR: Impact on Small RNA-Seq Profiling Validation. International Journal of Molecular Sciences (2023).
4. Genetic Regulation of Human isomiR Biogenesis. Cancers (2023).