Knowing is not enough; we must apply: the case for rigorous microRNA annotation standards

Area of Science:

• Molecular Biology
• Genomics
• Biochemistry

Background:

• MicroRNAs (miRNAs) are crucial small regulatory RNAs with significant biological roles.
• Extensive research has led to a high eagerness to classify new sequences as miRNAs, implying functional importance.
• Thousands of spurious miRNA entries in public repositories risk misinterpretation, especially in disease-associated studies.

Purpose of the Study:

• To develop and present a standardized, four-part checklist for evaluating putative microRNA candidates.
• To address the issue of spurious miRNA entries and improve the accuracy of miRNA annotation.
• To provide a tool for critical assessment of miRNA claims in translational research.

Main Methods:

• Development of a four-part checklist based on structural, genomic, functional, and expression criteria.
• Application of the checklist to evaluate "Mir-690" and nine other highly cited, uncurated sequences.
• Assessment of sequence features, target conservation, and expression patterns.

Main Results:

• "Mir-690" and nine other evaluated sequences failed to meet core miRNA annotation criteria.
• These sequences lacked essential structural features, conserved targets, and reproducible, miRNA-typical expression evidence.
• No support was found for their classification as genuine microRNAs.

Conclusions:

• Heightened scrutiny and standardized validation are essential in microRNA research.
• The proposed checklist offers a practical tool for authors, editors, reviewers, and readers to critically assess miRNA claims.
• Accurate miRNA identification is crucial, particularly when sequences are investigated as biomarkers or therapeutic targets.