MicroRNA expression and identification of putative miRNA targets in ovarian cancer.
BACKGROUND
MicroRNAs (miRNAs) represent a class of small non-coding RNAs that control gene expression by targeting mRNAs and triggering either translation repression or RNA degradation. Emerging evidence suggests the potential involvement of altered regulation of miRNA in the pathogenesis of cancers, and these genes are thought to function as both tumor suppressors and oncogenes.


RESULTS
Using microRNA microarrays, we identify several miRNAs aberrantly expressed in human ovarian cancer tissues and cell lines. miR-221 stands out as a highly elevated miRNA in ovarian cancer, while miR-21 and several members of the let-7 family are found downregulated. Public databases were used to reveal potential targets for the highly differentially expressed miRNAs. In order to experimentally identify transcripts whose stability may be affected by the differentially expressed miRNAs, we transfected precursor miRNAs into human cancer cell lines and used oligonucleotide microarrays to examine changes in the mRNA levels. Interestingly, there was little overlap between the predicted and the experimental targets or pathways, or between experimental targets/pathways obtained using different cell lines, highlighting the complexity of miRNA target selection.


CONCLUSIONS
Our results identify several differentially expressed miRNAs in ovarian cancer and identify potential target transcripts that may be regulated by these miRNAs. These miRNAs and their targets may have important roles in the initiation and development of ovarian cancer.
Dahiya
Neetu
N
Laboratory of Cellular and Molecular Biology, Hopkins Medical Institutions, Baltimore, Maryland, United States of America.
Sherman-Baust
Cheryl A
CA
Wang
Tian-Li
TL
Davidson
Ben
B
Shih
Ie-Ming
IeM
Zhang
Yongqing
Y
Wood
William
W
Becker
Kevin G
KG
Morin
Patrice J
PJ
D045744:Cell Line, Tumor; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D010051:Ovarian Neoplasms / Q000235:genetics*
D035683:MicroRNAs