title: Expression of the microRNA regulators Drosha, Dicer and Ago2 in non-small cell lung carcinomas.
abstract: OBJECTIVE
  MicroRNAs are evolutionarily conserved non-coding components of the transcriptome that can post-transcriptionally control gene expression. Altered microRNA expression has been found to be a common feature of several cancers, including lung carcinomas. The biogenesis and maturation of microRNAs is known to be mediated by the ribonucleases Drosha, Dicer and Ago2. The purpose of the present study was to investigate the expression and distribution of Drosha, Dicer and Ago2 in human non-small cell lung carcinomas (NSCLC) and to relate the respective expression patterns to clinocopatholical features.
  
  
  METHODS
  We used five human NSCLC-derived cell lines and primary formalin-fixed paraffin-embedded tissue samples from 83 NSCLC patients. Drosha, Dicer and Ago2 mRNA and protein expression levels, and their sub-cellular distributions, were assessed using RT-PCR, Western blotting, immunofluorescence and immunohistochemistry, respectively.
  
  
  RESULTS
  We found that Drosha, Dicer and Ago2 were expressed in all the cell lines and primary neoplastic and non-neoplastic tissue samples tested. The intensity of the immunohistochemical staining was found to be significantly lower in stage I tumors compared to normal lung tissues. Dicer expression was found to be significantly higher in stage II compared to stage I tumors, and in stage III compared to stage II and stage I tumors.
  
  
  CONCLUSIONS
  Our results point at a role of Drosha, Dicer and Ago2 in the development of NSCLC and suggest that Dicer may be implicated in the progression of these tumors to advanced stages.
authors.affiliation: Department of Anatomy-Histology-Embryology, University of Patras, School of Medicine, Patras, Greece.
authors.forename: E
authors.initials: E
authors.lastname: Prodromaki
authors.forename: A
authors.initials: A
authors.lastname: Korpetinou
authors.forename: E
authors.initials: E
authors.lastname: Giannopoulou
authors.forename: E
authors.initials: E
authors.lastname: Vlotinou
authors.forename: Μ
authors.initials: Μ
authors.lastname: Chatziathanasiadou
authors.forename: N I
authors.initials: NI
authors.lastname: Papachristou
authors.forename: C D
authors.initials: CD
authors.lastname: Scopa
authors.forename: H
authors.initials: H
authors.lastname: Papadaki
authors.forename: H P
authors.initials: HP
authors.lastname: Kalofonos
authors.forename: D J
authors.initials: DJ
authors.lastname: Papachristou
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D060565:Argonaute Proteins / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D045744:Cell Line, Tumor; D053487:DEAD-box RNA Helicases / Q000235:genetics / Q000378:metabolism*; D018450:Disease Progression; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D008297:Male; D035683:MicroRNAs / Q000235:genetics; D018613:Microscopy, Confocal; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D020133:Reverse Transcriptase Polymerase Chain Reaction; D043244:Ribonuclease III / Q000235:genetics / Q000378:metabolism*; D055752:Small Cell Lung Carcinoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology
chemical_list: C466422:AGO2 protein, human; D060565:Argonaute Proteins; D035683:MicroRNAs; C408087:DICER1 protein, human; C517918:DROSHA protein, human; D043244:Ribonuclease III; D053487:DEAD-box RNA Helicases