Objective: microRNA assessments in biological samples can be performed
by different methods that mainly rely on hybridization process, qPCR or
RNA sequencing. With the aim to detect and validate microRNA biomarkers in tumor
samples, we challenged the consistency of the quantitative results obtained with
the different methods.
Methods: We measured microRNA concentrations in several biological samples
such as cultured tumor cells or tumor tissues (frozen tissues or FFPE samples) using
different microRNA assay methods, in particular hybridization to AffymetrixTM arrays,
qPCR and digital droplet qPCR (BioradTM) based on Taqman microRNA assays
(Life TechnologiesTM). We also compared our results to other data that have
been obtained with different technical approaches and available in the literature.
Results: We found poor consistency for the microRNA amounts measured in the samples assayed by
the different methods. Both technical platforms and microRNA assays protocols may be responsible for
the observed inconsistencies.
Conclusion: When assaying microRNAs for clinical purpose or fundamental researches it seems necessary
to keep in mind the specific pitfalls of all the microRNA detection methods such as those we disclose
here. Obviously, valid inter sample comparisons and meaningful multicenter studies can only be
obtained when microRNA assessments are strictly performed with identical technical approaches and