title: Enrichment of A Rare Subpopulation of miR-302-Expressing Glioma Cells by Serum Deprivation.
abstract: OBJECTIVE
  MiR-302-367 is a cluster of polycistronic microRNAs that are exclusively expressed in embryonic stem (ES) cells. The miR-302-367 promoter is functional during embryonic development but is turned off in later stages. Motivated by the cancer stem cell hypothesis, we explored the potential expression of miR-302 in brain tumor cell lines.
  
  
  METHODS
  In the present experimental study, we have tried to expand our knowledge on the expression pattern and functionality of miR302 cluster by quantifying its expression in a series of glioma (A-172, 1321N1, U87MG) and medulloblastoma (DAOY) cell lines. To further assess the functionality of miR-302 in these cell lines, we cloned its promoter core region upstream of the enhanced green fluorescent protein (EGFP) or luciferase encoding genes.
  
  
  RESULTS
  Our data demonstrated a very low expression of miR-302 in glioma cell lines, compared with that of embryonal carcinoma cell line NT2 being used as a positive control. The expression of miR-302 promoter-EGFP construct in the aforementioned cell lines demonstrated GFP expression in a rare subpopulation of the cells. Serum deprivation led to the generation of tumorospheres, enrichment of miR-302 positive cells and upregulation of a number of pluripotency genes.
  
  
  CONCLUSIONS
  Taken together, our data suggest that miR-302 could potentially be used as a novel putative cancer stem cell marker to identify and target cancer stem cells within tumor tissues.
authors: Nanomedicine and Tissue Engineering Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors: Mahmoud-Reza
authors: MR
authors: Rafiee
authors: Nanomedicine and Tissue Engineering Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran ; Department of Non-coding RNA Research, Pars Genome Company, Tehran, Iran.
authors: Afsaneh
authors: A
authors: Malekzadeh Shafaroudi
authors: Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran.
authors: Sara
authors: S
authors: Rohban
authors: Nanomedicine and Tissue Engineering Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors: Hamid
authors: H
authors: Khayatzadeh
authors: Department of Chemistry, Sharif University, Tehran, Iran.
authors: Hamid Reza
authors: HR
authors: Kalhor
authors: Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran.
authors: Seyed Javad
authors: SJ
authors: Mowla
keywords: Cancer Stem Cell; Gene Expression; Glioma; miR-302; microRNA