Genomic and epigenetic alterations deregulate microRNA expression in human epithelial ovarian cancer

Proc Natl Acad Sci U S A. 2008 May 13;105(19):7004-9. doi: 10.1073/pnas.0801615105. Epub 2008 May 5.

Abstract

MicroRNAs (miRNAs) are an abundant class of small noncoding RNAs that function as negative gene regulators. miRNA deregulation is involved in the initiation and progression of human cancer; however, the underlying mechanism and its contributions to genome-wide transcriptional changes in cancer are still largely unknown. We studied miRNA deregulation in human epithelial ovarian cancer by integrative genomic approach, including miRNA microarray (n = 106), array-based comparative genomic hybridization (n = 109), cDNA microarray (n = 76), and tissue array (n = 504). miRNA expression is markedly down-regulated in malignant transformation and tumor progression. Genomic copy number loss and epigenetic silencing, respectively, may account for the down-regulation of approximately 15% and at least approximately 36% of miRNAs in advanced ovarian tumors and miRNA down-regulation contributes to a genome-wide transcriptional deregulation. Last, eight miRNAs located in the chromosome 14 miRNA cluster (Dlk1-Gtl2 domain) were identified as potential tumor suppressor genes. Therefore, our results suggest that miRNAs may offer new biomarkers and therapeutic targets in epithelial ovarian cancer.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • DNA, Neoplasm
  • Down-Regulation / genetics
  • Epigenesis, Genetic*
  • Epithelial Cells / metabolism*
  • Epithelial Cells / pathology*
  • Female
  • Gene Expression Profiling
  • Gene Expression Regulation, Neoplastic*
  • Genome, Human / genetics*
  • Humans
  • MicroRNAs / genetics*
  • Neoplasm Staging
  • Ovarian Neoplasms / genetics*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Ribonuclease III / genetics
  • Survival Analysis

Substances

  • DNA, Neoplasm
  • MicroRNAs
  • RNA, Messenger
  • DROSHA protein, human
  • Ribonuclease III