  Dysregulated microRNA (miRNA) expression is a well-established feature of
human cancer. However, the role of specific miRNAs in determining cancer
outcomes remains unclear. Using Level 3 expression data from the Cancer Genome
Atlas (TCGA), we identified 61 miRNAs that are associated with overall survival
in 469 ovarian cancers profiled by microarray (p<0.01). We also identified 12
miRNAs that are associated with survival when miRNAs were profiled in the same
specimens using Next Generation Sequencing (miRNA-Seq) (p<0.01). Surprisingly,
only 1 miRNA transcript is associated with ovarian cancer survival in both
datasets. Our analyses indicate that this discrepancy is due to the fact that
miRNA levels reported by the two platforms correlate poorly, even after
correcting for potential issues inherent to signal detection algorithms.
Further investigation is warranted.
