title: Expression of Dicer and Drosha in triple-negative breast cancer.
abstract: OBJECTIVE
  Dicer and Drosha are components of the miRNA-producing machinery and their altered expression may play a role in cancer progression. The main purpose of this study was a detailed investigation of Dicer and Drosha expression and localisation in triple-negative breast cancers.
  
  
  METHODS
  Thirty-one triple-negative breast cancers and several breast cancer cell lines were investigated. Expression of Dicer and Drosha was evaluated at the mRNA level by quantitative reverse transcription PCR and at the protein level by immunohistochemistry or western blot.
  
  
  RESULTS
  Compared with normal breast tissues, a wide variation of Dicer and Drosha mRNA levels was detected in triple-negative breast cancers. As a group, Drosha mRNA levels in triple-negative breast cancers were significantly higher than those in normal breast tissues. Immunohistochemical data confirmed higher expression of Drosha protein in triple-negative breast cancers. In normal breast tissues Dicer was detectable predominantly in the cytoplasm of basal/myoepithelial cells only. In contrast, in the majority of triple-negative breast cancers, intense Dicer staining was detectable also in the nuclear compartment. Detection of Dicer and Drosha mRNA and protein levels in breast cancer cell lines confirmed the nuclear localisation of Dicer, suggesting, in addition, that the steady-state protein levels could be controlled by post-mRNA regulatory events.
  
  
  CONCLUSIONS
  These findings indicate that Dicer and Drosha expression is deregulated in triple-negative breast cancers.
authors.affiliation: Dipartimento di Scienze Mediche e Biologiche, Università di Udine, Udine, Italy.
authors.forename: Nadia
authors.initials: N
authors.lastname: Passon
authors.forename: Anna
authors.initials: A
authors.lastname: Gerometta
authors.forename: Cinzia
authors.initials: C
authors.lastname: Puppin
authors.forename: Elisa
authors.initials: E
authors.lastname: Lavarone
authors.forename: Fabio
authors.initials: F
authors.lastname: Puglisi
authors.forename: Gianluca
authors.initials: G
authors.lastname: Tell
authors.forename: Carla
authors.initials: C
authors.lastname: Di Loreto
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Damante
mesh_terms: D015153:Blotting, Western; D001943:Breast Neoplasms / Q000378:metabolism*; D045744:Cell Line, Tumor; D021984:Cyclophilin A / Q000235:genetics / Q000378:metabolism; D053487:DEAD-box RNA Helicases / Q000378:metabolism*; D015536:Down-Regulation; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D043244:Ribonuclease III / Q000378:metabolism*; D012269:Ribosomal Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: C496590:MRPL19 protein, human; D024101:Mitochondrial Proteins; D012333:RNA, Messenger; D012269:Ribosomal Proteins; C408087:DICER1 protein, human; C517918:DROSHA protein, human; D043244:Ribonuclease III; D053487:DEAD-box RNA Helicases; D021984:Cyclophilin A