Unlocking pathology archives for microRNA-profiling.
BACKGROUND
MicroRNAs (miRNAs) are approximately 22 nucleotide long, non-coding RNAs that regulate gene expression by binding to the 3'-untranslated region of target mRNAs and also a variety of cellular processes. It has recently been established that dysregulation of miRNA expression can be detected in the majority of human cancers. A variety of high-throughput screening methods has been developed to identify dysregulated miRNA species in tumours. For retrospective clinical studies formalin-fixed, paraffin-embedded (FFPE) tissue is the most widely used material.


METHODS
The miRNA expression profiles of freshly frozen (CRYO) and FFPE tissues of seven tonsil and four liver samples were compared, using a qPCR-based assay, profiling 157 miRNA species.


RESULTS
The significance of miRNA-profiles was barely influenced by FFPE treatment in both tissues and the variance induced by FFPE treatment was much smaller than the variance caused by biologically based differential expression.


CONCLUSIONS
FFPE material is well suited for miRNA profiling.
Hoefig
Kai P
KP
Institute for Pathology, UKSH Campus Luebeck, Luebeck, Germany.
Thorns
Christoph
C
Roehle
Anja
A
Kaehler
Christian
C
Wesche
Kai O
KO
Repsilber
Dirk
D
Branke
Biggi
B
Thiere
Marlen
M
Feller
Alfred C
AC
Merz
Hartmut
H
D001483:Base Sequence; D005557:Formaldehyde; D005629:Frozen Sections; D020869:Gene Expression Profiling; D006801:Humans; D008113:Liver Neoplasms / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D035683:MicroRNAs / Q000096:biosynthesis* / Q000235:genetics; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012189:Retrospective Studies; D016707:Tissue Fixation; D014067:Tonsillar Neoplasms / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism / Q000473:pathology
D035683:MicroRNAs; D005557:Formaldehyde