Data from: MicroRNA stability in FFPE tissue samples: dependence on GC content

MicroRNAs (miRNAs) are small non-coding RNAs responsible for fine-tuning
of gene expression at post-transcriptional level. The alterations in miRNA
expression levels profoundly affect human health and often lead to the
development of severe diseases. Currently, high throughput analyses, such
as microarray and deep sequencing, are performed in order to identify
miRNA biomarkers, using archival patient tissue samples. MiRNAs are more
robust than longer RNAs, and resistant to extreme temperatures, pH, and
formalin-fixed paraffin-embedding (FFPE) process. Here, we have compared
the stability of miRNAs in FFPE cardiac tissues using next-generation
sequencing. The mode read length in FFPE samples was 11 nucleotides (nt),
while that in the matched frozen samples was 22 nt. Although the read
counts were increased 1.7-fold in FFPE samples, compared with those in the
frozen samples, the average miRNA mapping rate decreased from 32.0% to
9.4%. These results indicate that, in addition to the fragmentation of
longer RNAs, miRNAs are to some extent degraded in FFPE tissues as well.
The expression profiles of total miRNAs in two groups were highly
correlated (0.88