Differentiation-associated microRNAs antagonize the Rb-E2F pathway to restrict proliferation

J Cell Biol. 2012 Oct 1;199(1):77-95. doi: 10.1083/jcb.201206033.

Abstract

The cancer-associated loss of microRNA (miRNA) expression leads to a proliferative advantage and aggressive behavior through largely unknown mechanisms. Here, we exploit a model system that recapitulates physiological terminal differentiation and its reversal upon oncogene expression to analyze coordinated mRNA/miRNA responses. The cell cycle reentry of myotubes, forced by the E1A oncogene, was associated with a pattern of mRNA/miRNA modulation that was largely reciprocal to that induced during the differentiation of myoblasts into myotubes. The E1A-induced mRNA response was preponderantly Retinoblastoma protein (Rb)-dependent. Conversely, the miRNA response was mostly Rb-independent and exerted through tissue-specific factors and Myc. A subset of these miRNAs (miR-1, miR-34, miR-22, miR-365, miR-29, miR-145, and Let-7) was shown to coordinately target Rb-dependent cell cycle and DNA replication mRNAs. Thus, a dual level of regulation-transcriptional regulation via Rb-E2F and posttranscriptional regulation via miRNAs-confers robustness to cell cycle control and provides a molecular basis to understand the role of miRNA subversion in cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenovirus E1A Proteins / metabolism
  • Animals
  • Cell Differentiation / genetics*
  • Cell Proliferation
  • Cells, Cultured
  • E2F Transcription Factors / genetics
  • E2F Transcription Factors / metabolism*
  • HEK293 Cells
  • Humans
  • Mice
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • Myoblasts / cytology
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Retinoblastoma Protein / genetics
  • Retinoblastoma Protein / metabolism*

Substances

  • Adenovirus E1A Proteins
  • E2F Transcription Factors
  • MicroRNAs
  • RNA, Messenger
  • Retinoblastoma Protein