Finding the needle in the haystack

Access through your institution Buy or subscribe The authors first verified that endogenous miRNAs could be detected in plasma. Total RNA isolated from the plasma of healthy subjects was

radiolabelled and subjected to PAGE followed by reverse transcriptase PCR and cDNA sequencing. These experiments demonstrated that the majority of small ∼22 nucleotide RNA species present

corresponded to known miRNAs. Moreover, levels of three endogenous miRNAs — _miR-15b, miR-16_ and _miR-24 —_ remained constant after subsequent freeze–thaw cycles, which is indicative of

stability, a prerequisite for any potential biomarker. The next challenge was to demonstrate that tumour-derived miRNAs could be detected in plasma. The authors addressed this by isolating

RNA from the plasma of mice with human prostate cancer xenografts that had been growing for 28 days. _Taq_man quantitative real-time PCR (qRT-PCR), showed the presence of two miRNA

sequences, _miR-629_* and _miR-660_, in experimental but not control animals. As both these miRNAs lack murine homologues they were considered to be specific, tumour-derived markers.

Significantly, their levels correlated with tumour burden, further reinforcing the validity of this approach. This is a preview of subscription content, access via your institution ACCESS

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SpringerLink * Instant access to full article PDF Buy now Prices may be subject to local taxes which are calculated during checkout ADDITIONAL ACCESS OPTIONS: * Log in * Learn about

institutional subscriptions * Read our FAQs * Contact customer support REFERENCES ORIGINAL RESEARCH PAPER * Mitchell, P. S. et al. Circulating microRNAs as stable blood-based markers for

cancer detection. _Proc. Natl Acad. Sci. USA_ 105, 10513–10518 (2008) Article  CAS  Google Scholar  FURTHER READING * Ludwig, J. A. et al. Biomarkers in cancer staging, prognosis and

treatment selection. _Nature Rev. Cancer_ 5, 845–856 (2005) Article  CAS  Google Scholar  Download references Authors * Safia Ali Danovi View author publications You can also search for this

author inPubMed Google Scholar RIGHTS AND PERMISSIONS Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Ali Danovi, S. Finding the needle in the haystack. _Nat Rev Cancer_ 8,

659 (2008). https://doi.org/10.1038/nrc2474 Download citation * Published: 14 August 2008 * Issue Date: September 2008 * DOI: https://doi.org/10.1038/nrc2474 SHARE THIS ARTICLE Anyone you

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