title: The role of miRNAs in drug resistance and prognosis of breast cancer formalin-fixed paraffin-embedded tissues.
abstract: OBJECTIVE
  Chemoresistance mediated by miRNAs in breast cancer have been already validated by previous studies in vitro, while little is known concerning the expression of them in vivo. The aim of this study was to investigate the role of miR-222, miR-29a, miR-34a, miR-130a, miR-90b, miR-200b, miR-452, miR-197, miR-138, miR-210, miR-423, miR-4298, miR-4644, miR-139, miR-1246, miR-1268a, miR-140, miR-149, miR-3178, miR-3613, miR-4258, miR-574, miR-671, miR-6780b, miR-7107, miR-744 and miR-7847 linked to drug resistance in breast cancer formalin-fixed paraffin-embedded tissues and the association of prognosis with miRNAs, thus providing effective targets in chemotherapy, as well as potential biomarkers for guiding effective treatments of breast cancer.
  
  
  METHODS
  The relationship between the expression of diverse miRNAs and drug resistance was detected by RT-qPCR using 55 breast cancer FFPE tissues containing 26 paired FFPE specimens.
  
  
  RESULTS
  MiR-222, miR-29a, miR-34a, miR-423, miR-140, miR-3178, miR-574, miR-6780b and miR-744 exhibited significantly higher expression levels in surgically-resected specimens compared with pre-neoadjuvant chemotherapy biopsies. Evidently high expression of miR-222, miR-29a, miR-140, miR-574, miR-6780b, miR-7107 and miR-744 were found in ineffective group comparing with effective group. Further investigations revealed the significant association between several miRNAs in breast cancer patients.
  
  
  CONCLUSIONS
  This study highlights the role of numerous miRNAs in prediction of therapeutic responses and suggests that specific miRNAs could serve as valuable sources for biomarker detections and optimal chemotherapeutic choices for breast cancer patients.
authors.affiliation: The Fourth Clinical School of Nanjing Medical University, 210009 Nanjing, China; Department of General Surgery, Jiangsu Cancer Hospital Affiliated to Nanjing Medical University, Baiziting42, 210009 Nanjing, China; The First Affiliated Hospital of Nanjing Medical University, Guangzhoulu300, 210029 Nanjing, China.
authors.forename: Xiu
authors.initials: X
authors.lastname: Chen
authors.affiliation: School of Public Health Nanjing Medical University, 210009 Nanjing, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Lu
authors.affiliation: The First Clinical School of Nanjing Medical University, 210009 Nanjing, China.
authors.forename: Dan-Dan
authors.initials: DD
authors.lastname: Wang
authors.affiliation: The Fourth Clinical School of Nanjing Medical University, 210009 Nanjing, China.
authors.forename: Su-Jin
authors.initials: SJ
authors.lastname: Yang
authors.affiliation: The First Clinical School of Nanjing Medical University, 210009 Nanjing, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wu
authors.affiliation: The Fourth Clinical School of Nanjing Medical University, 210009 Nanjing, China.
authors.forename: Hong-Yu
authors.initials: HY
authors.lastname: Shen
authors.affiliation: The First Affiliated Hospital of Nanjing Medical University, Guangzhoulu300, 210029 Nanjing, China.
authors.forename: Shan-Liang
authors.initials: SL
authors.lastname: Zhong
authors.affiliation: Center of Clinical Laboratory Science, Jiangsu Cancer Hospital Affiliated to Nanjing Medical University, Baiziting42, 210009 Nanjing, China. Electronic address: jsccljhzhao@126.com.
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Zhao
authors.affiliation: Department of General Surgery, Jiangsu Cancer Hospital Affiliated to Nanjing Medical University, Baiziting42, 210009 Nanjing, China; The First Affiliated Hospital of Nanjing Medical University, Guangzhoulu300, 210029 Nanjing, China. Electronic address: jschjhtang@163.com.
authors.forename: Jin-Hai
authors.initials: JH
authors.lastname: Tang
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000473:pathology; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D005260:Female; D005557:Formaldehyde; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D035683:MicroRNAs; D016612:Paraffin Embedding; D011379:Prognosis; D012189:Retrospective Studies; D016707:Tissue Fixation / Q000379:methods
chemical_list: D014408:Biomarkers, Tumor; D035683:MicroRNAs; D005557:Formaldehyde
keywords: Breast cancer; Drug resistance; FFPE; miRNA