miR-200c inhibits invasion, migration and proliferation of bladder cancer cells through down-regulation of BMI-1 and E2F3

J Transl Med. 2014 Nov 4;12:305. doi: 10.1186/s12967-014-0305-z.

Abstract

Background: MicroRNA-200c (miR-200c) is one of the short noncoding RNAs that play crucial roles in tumorigenesis and tumor progression. It also acts as considerable modulator in the process of epithelial-to-mesenchymal transition (EMT), a cell development regulating process that affects tumor development and metastasis. However, the role of miR-200c in bladder cancer cells and its mechanism has not been well studied. The purpose of this study was to determine the potential role of miR-200c in regulating EMT and how it contributed to bladder cancer cells in invasion, migration and proliferation.

Methods: Real-time reverse transcription-PCR was used to identify and validate the differential expression of MiR-200c involved in EMT in 4 bladder cancer cell lines and clinical specimens. A list of potential miR-200 direct targets was identified through the TargetScan database. The precursor of miR-200c was over-expressed in UMUC-3 and T24 cells using a lentivirus construct, respectively. Protein expression and signaling pathway modulation were validated through Western blot analysis and confocal microscopy, whereas BMI-1 and E2F3, direct target of miR-200c, were validated by using the wild-type and mutant 3'-untranslated region BMI-1/E2F3 luciferase reporters.

Results: We demonstrate that MiR-200c is down-regulated in bladder cancer specimens compared with adjacent ones in the same patient. Luciferase assays showed that the direct down-regulation of BMI-1 and E2F3 were miR-200c-dependent because mutations in the two putative miR-200c-binding sites have rescued the inhibitory effect. Over-expression of miR-200c in bladder cancer cells resulted in significantly decreased the capacities of cell invasion, migration and proliferation. miR-200c over-expression resulted in conspicuous down-regulation of BMI-1 and E2F3 expression and in a concomitant increase in E-cadherin levels.

Conclusions: miR-200c appears to control the EMT process through BMI-1 in bladder cancer cells, and it inhibits their proliferation through down-regulating E2F3. The targets of miR-200c include BMI-1 and E2F3, which are a novel regulator of EMT and a regulator of proliferation, respectively.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, CD
  • Base Sequence
  • Cadherins / metabolism
  • Cell Line, Tumor
  • Cell Movement* / genetics
  • Cell Proliferation
  • Down-Regulation / genetics*
  • E2F3 Transcription Factor / genetics*
  • E2F3 Transcription Factor / metabolism
  • Gene Expression Regulation, Neoplastic
  • Humans
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • Molecular Sequence Data
  • Neoplasm Invasiveness
  • Neoplasm Metastasis
  • Polycomb Repressive Complex 1 / genetics*
  • Polycomb Repressive Complex 1 / metabolism
  • Up-Regulation / genetics
  • Urinary Bladder Neoplasms / genetics*
  • Urinary Bladder Neoplasms / pathology*

Substances

  • Antigens, CD
  • BMI1 protein, human
  • CDH1 protein, human
  • Cadherins
  • E2F3 Transcription Factor
  • E2F3 protein, human
  • MIRN200 microRNA, human
  • MicroRNAs
  • Polycomb Repressive Complex 1