title: MiR-34b is associated with clinical outcome in triple-negative breast cancer patients.
abstract: BACKGROUND
  Breast cancer is the most common malignancy with the highest incidence rates among women worldwide. Triple-negative breast cancer (TNBC) represents the major phenotype of basal-like molecular subtype of breast cancer, characterized by higher incidence in young women and a very poor prognosis. MicroRNAs (miRNAs) are small non-coding RNAs playing significant role in the pathogenesis of many cancers including breast cancer. Therefore, miRNAs are also potential prognostic and/or predictive biomarkers in triple-negative breast cancer patients.
  
  
  METHODS
  Thirty-nine TNBC patients with available formalin-fixed paraffin-embedded (FFPE) tissues were enrolled in the study. MiR-34a, miR-34b, and miR-34c were analyzed using qRT-PCR and correlated to clinico-pathological features of TNBC patients.
  
  
  RESULTS
  Expression levels of miR-34b significantly correlate with disease free survival (DFS) (p = 0.0020, log-rank test) and overall survival (OS) (p = 0.0008, log-rank test) of TNBC patients. No other significant associations between miR-34a, miR-34b, and miR-34c with available clinical pathological data were observed.
  
  
  CONCLUSIONS
  MiR-34b expression negatively correlates with disease free survival and overall survival in TNBC patients. Thus, miR-34b may present a new promising prognostic biomarker in TNBC patients, but independent validations are necessary.
authors.affiliation: Department of Comprehensive Cancer Care, Masaryk Memorial Cancer Institute, Zluty kopec 7, Brno 656 53, the Czech Republic. msvoboda@mou.cz
authors.forename: Marek
authors.initials: M
authors.lastname: Svoboda
authors.forename: Jiri
authors.initials: J
authors.lastname: Sana
authors.forename: Martina
authors.initials: M
authors.lastname: Redova
authors.forename: Jiri
authors.initials: J
authors.lastname: Navratil
authors.forename: Marketa
authors.initials: M
authors.lastname: Palacova
authors.forename: Pavel
authors.initials: P
authors.lastname: Fabian
authors.forename: Ondrej
authors.initials: O
authors.lastname: Slaby
authors.forename: Rostislav
authors.initials: R
authors.lastname: Vyzula
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000235:genetics*; D001943:Breast Neoplasms / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D018572:Disease-Free Survival; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D053208:Kaplan-Meier Estimate; D035683:MicroRNAs / Q000032:analysis / Q000235:genetics*; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D060888:Real-Time Polymerase Chain Reaction; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis / Q000235:genetics; D011960:Receptors, Estrogen / Q000096:biosynthesis / Q000235:genetics; D011980:Receptors, Progesterone / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D014408:Biomarkers, Tumor; D035683:MicroRNAs; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C522425:MIRN34 microRNA, human