PURPOSE: The proper validation of prognostic biomarkers is an important clinical issue
in breast cancer research. MicroRNAs (miRNAs) have emerged as a new class of promising
breast cancer biomarkers. In the present work, we developed an integrated online bioinformatic
tool to validate the prognostic relevance of miRNAs in breast cancer. METHODS: A database
was set up by searching the GEO, EGA, TCGA, and PubMed repositories to identify datasets
with published miRNA expression and clinical data. Kaplan-Meier survival analysis
was performed to validate the prognostic value of a set of 41 previously published
survival-associated miRNAs. RESULTS: All together 2178 samples from four independent
datasets were integrated into the system including the expression of 1052 distinct
human miRNAs. In addition, the web-tool allows for the selection of patients, which
can be filtered by receptors status, lymph node involvement, histological grade, and
treatments. The complete analysis tool can be accessed online at: www.kmplot.com/mirpower
. We used this tool to analyze a large number of deregulated miRNAs associated with
breast cancer features and outcome, and confirmed the prognostic value of 26 miRNAs.
A significant correlation in three out of four datasets was validated only for miR-29c
and miR-101. CONCLUSIONS: In summary, we established an integrated platform capable
to mine all available miRNA data to perform a survival analysis for the identification
and validation of prognostic miRNA markers in breast cancer.
