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Updated: Apr 26, 2026
Isolating, Sequencing and Analyzing Extracellular MicroRNAs from Human Mesenchymal Stem Cells
Published on: March 8, 2019
Isolation of secreted microRNAs (miRNAs) from cell-conditioned media
Claire L Glynn, Sonja Khan, Michael J Kerin
1Discipline of Surgery, School of Medicine, Clinical Science Institute, National University of Ireland Galway, Costello Road, Galway, Ireland.
Abstract:
MicroRNAs (miRNAs) have been found to be stable in the circulation of cancer patients raising their potential as circulating biomarkers of disease. The specific source and role, however, of miRNAs in the circulation is unknown and requires elucidation to determine their true potential. In this study, along with primary tissue explants and primary stromal cells, three breast cancer cell lines were employed, including T47D, MDA-MB-231 and SK-BR-3. Tissue explants were harvested in theatre, with informed patient consent, and included tumour, tumour associated normal, and diseased lymph node samples. Cell-conditioned media containing all factors secreted by the cells were harvested. MiRNAs were extracted from samples using 5 different extraction techniques including the blood protocol, RNeasy® (Qiagen), miRNeasy®mini kit (Qiagen), mirVana™ isolation kit (Ambion) and RNAqueous® kit (Ambion). MiRNAs were successfully isolated from all media samples collected from cell lines, primary cells and fresh tissue explants. However, there was remarkable variation in yield depending on the extraction method used. Aliquots of the same samples were extracted, revealing the two column extraction protocol of the mirVana® miRNA isolation kit to be the most suitable approach. A range of miRNAs, including miR-16, miR-195, miR-497 and miR-10b, were successfully amplified. While miR-16 and miR-195 were detected in media from both cell lines and tissue explants, miR-497 and miR-10b were only detected in secretions from whole tissue explants. The ability to achieve reliable and reproducible miRNA yields from cell-conditioned media is vital for the successful amplification of miRNAs by RQ-PCR.
Insights
This study identifies optimal methods for isolating circulating microRNAs (miRNAs) from breast cancer cell secretions. Reliable miRNA extraction from cell-conditioned media is crucial for developing diagnostic biomarkers.
Area of Science:
- Biochemistry
- Molecular Biology
- Oncology
Background:
- Circulating microRNAs (miRNAs) show potential as cancer biomarkers due to their stability.
- The origin and function of circulating miRNAs remain largely uncharacterized.
- Understanding miRNA secretion is key to unlocking their diagnostic utility.
Purpose of the Study:
- To evaluate different miRNA extraction techniques for cell-conditioned media.
- To identify the most effective method for isolating miRNAs from breast cancer cell secretions.
- To determine the presence of specific miRNAs in secretions from cell lines and tissue explants.
Main Methods:
- Utilized three breast cancer cell lines (T47D, MDA-MB-231, SK-BR-3) and primary tissue explants.
- Collected cell-conditioned media and tissue secretions.
- Compared five distinct miRNA extraction methods, including column-based kits.
- Amplified selected miRNAs using quantitative reverse transcription PCR (RQ-PCR).
Main Results:
- Successfully isolated miRNAs from cell lines, primary cells, and tissue explants.
- Demonstrated significant variation in miRNA yield based on the extraction method.
- Identified the mirVana™ miRNA isolation kit's two-column protocol as the most effective.
- Detected specific miRNAs (miR-16, miR-195, miR-497, miR-10b) in secretions, with differential presence between cell lines and tissue.
Conclusions:
- The mirVana™ miRNA isolation kit provides reliable and reproducible miRNA yields from cell-conditioned media.
- Effective miRNA isolation is essential for successful RQ-PCR amplification.
- This methodology facilitates further research into circulating miRNAs as cancer biomarkers.
