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Updated: May 16, 2026
MicroRNA Based Liquid Biopsy: The Experience of the Plasma miRNA Signature Classifier (MSC) for Lung Cancer Screening
Published on: October 26, 2017
MicroRNAs are suitable for assessment as biomarkers from formalin-fixed paraffin-embedded tissue, and miR-24
Rachel Emily Culpin1, Michal Sieniawski, Stephen John Proctor
1Academic Haematology, Northern Institute for Cancer Research, Newcastle University, Newcastle Upon Tyne, Tyne and Wear, UK. Rachel.culpin@ncl.ac.uk
Abstract:
Tissue biopsy specimens in the form of formalin-fixed paraffin-embedded tissue (FFPET) represent a valuable resource for biomarker identification and validation. However, to date, they remain an underused asset due to uncertainty regarding RNA extraction and the reliability of downstream techniques, including quantitative RT-PCR. Recently, much interest has emerged in the study of microRNAs; small single-stranded RNAs with a role in transcriptional regulation, that are thought to be well preserved in FFPET. In this study, we show that microRNA expression is comparable between FFPET and matched fresh-frozen samples (miR-17-5p: p=0.01, miR-92: p=0.003), and demonstrate that no significant deterioration in expression occurs over prolonged FFPET storage (p=0.06). Furthermore, microRNA expression is equivalent dependant on RNA extraction method (p<0.001) or DNAse treatment of total RNA (p<0.001). Finally, we validate miR-24 as a suitable reference microRNA for diffuse large B-cell lymphoma (DLBCL) FFPET studies.
Insights
MicroRNA expression is stable in formalin-fixed paraffin-embedded tissue (FFPET) samples, even after long-term storage. This validates FFPET as a reliable source for microRNA biomarker studies, including in diffuse large B-cell lymphoma (DLBCL).
Area of Science:
- Molecular Biology
- Genomics
- Biopathology
Background:
- Formalin-fixed paraffin-embedded tissue (FFPET) is a valuable resource for biomarker discovery.
- RNA extraction and downstream analyses from FFPET can be challenging.
- MicroRNAs are small RNAs with regulatory roles, potentially well-preserved in FFPET.
Purpose of the Study:
- To assess microRNA expression stability in FFPET.
- To evaluate the impact of storage duration and RNA extraction methods on microRNA integrity.
- To identify a suitable reference microRNA for diffuse large B-cell lymphoma (DLBCL) FFPET studies.
Main Methods:
- Quantitative RT-PCR was used to measure microRNA expression.
- Comparison of microRNA expression between FFPET and fresh-frozen samples.
- Analysis of microRNA expression stability over prolonged FFPET storage.
- Evaluation of different RNA extraction methods and DNase treatment effects.
- Validation of reference microRNAs in DLBCL FFPET samples.
Main Results:
- MicroRNA expression in FFPET is comparable to fresh-frozen samples (e.g., miR-17-5p, miR-92).
- No significant microRNA expression deterioration was observed with prolonged FFPET storage.
- MicroRNA expression levels were consistent across different RNA extraction methods and DNase treatments.
- miR-24 was validated as a suitable reference microRNA for DLBCL FFPET studies.
Conclusions:
- FFPET is a reliable source for microRNA expression studies.
- MicroRNA expression is robust to variations in RNA extraction and storage conditions.
- miR-24 is a validated reference microRNA for DLBCL FFPET research.
