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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
21
pubmed:dateCreated
2007-11-2
pubmed:abstractText
MicroRNAs (miRNA) are endogenous noncoding small RNAs that regulate the activity of mRNAs. Many miRNA genes, including let-7a-3, are located in CpG islands, suggesting possible epigenetic regulation of their expression. Promoter CpG island methylation of tumor suppressor genes is involved in cancer development and progression. Using real-time methylation-specific PCR and real-time reverse transcription-PCR, we analyzed DNA methylation in the let-7a-3 gene and miRNA expression of let-7a in 214 patients with epithelial ovarian cancer to assess the effect of let-7a-3 methylation on the expressions of let-7a as well as a possible target of let-7 regulation, insulin-like growth factor-II (IGF-II). The association of let-7a-3 methylation with patient survival outcomes was also evaluated. let-7a-3 methylation was detected in epithelial ovarian cancer, and the expression of let-7a was slightly affected by the methylation, but the effect was not substantial. The methylation of let-7a-3, however, was inversely correlated with IGF-II expression and positively with insulin-like growth factor binding protein-3 (IGFBP-3) expression. Patients with methylated let-7a-3 seemed to have reduced risk for death compared with those without, and the association was independent of patient age at surgery, tumor grade, disease stage, and IGF-II or IGFBP-3 expression. No association was found for let-7a-3 methylation and disease progression. These results suggest that the let-7a-3 gene is methylated and the methylation may affect IGF-II expression and the survival of ovarian cancer patients. Further investigation of the role of miRNAs and their regulation in cancer is warranted.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
1538-7445
pubmed:author
pubmed:issnType
Electronic
pubmed:day
1
pubmed:volume
67
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
10117-22
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Hypermethylation of let-7a-3 in epithelial ovarian cancer is associated with low insulin-like growth factor-II expression and favorable prognosis.
pubmed:affiliation
Department of Epidemiology and Public Health, Yale Cancer Center, Yale University School of Medicine, New Haven, CT 06520-8034, USA.
pubmed:publicationType
Journal Article