title: Down-regulation of miR-199b-5p is correlated with poor prognosis for breast cancer patients.
abstract: OBJECTIVE
  The purpose of the present study was to evaluate the prognostic value of miR-199b-5p in breast cancer patients, as well as explore its effects on breast cancer cells.
  
  
  METHODS
  The expression level of miR-199b-5p in breast cancer tissues and paired non-cancerous tissues were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Chi-square test was used to evaluate the relationship between miR-199b-5p expression and clinical parameters. Besides, overall survival analysis was carried out with Kaplan-Meier curve with log rank test, and the prognostic value of miR-199b-5p in breast cancer was evaluated by cox regression model. In addition, MTT and transwell assays in vitro were used to estimate the effects of miR-199b-5p on breast cancer cells.
  
  
  RESULTS
  MiR-199b-5p was down-regulated in breast cancer tissues, compared with adjacent normal tissues (P<0.05). Moreover, its decreased level was significantly correlated with advanced TNM stage (P=0.008) and positive lymph node metastasis (P=0.013). Cell experiments suggested that miR-199b-5p could regulate proliferation and invasion of breast cancer cells. In addition, we found that breast cancer patients with low miR-199b-5p expression level had poorer overall survival than those with high level (log rank test, P=0.021). MiR-199b-5p was an independent prognostic factor for breast cancer patients (HR=2.318, 95%CI=1.086-4.949, P=0.030).
  
  
  CONCLUSIONS
  Down-regulated miR-199b-5p in breast cancer patients is associated with malignant clinical characteristics. MiR-199b-5p may be a potential prognostic biomarker for breast cancer.
authors: Department of Laboratory Medicine and Center for Gene Diagnosis, Zhongnan Hospital of Wuhan University, Wuhan 430071, China; Center for Evidence-Based and Translational Medicine, Zhongnan Hospital of Wuhan University, Wuhan 430071, China.
authors: Cheng
authors: C
authors: Fang
authors: Department of Laboratory Medicine and Center for Gene Diagnosis, Zhongnan Hospital of Wuhan University, Wuhan 430071, China.
authors: Fu-Bing
authors: FB
authors: Wang
authors: Department of Laboratory Medicine and Center for Gene Diagnosis, Zhongnan Hospital of Wuhan University, Wuhan 430071, China. Electronic address: liyirong838@163.com.
authors: Yirong
authors: Y
authors: Li
authors: Center for Evidence-Based and Translational Medicine, Zhongnan Hospital of Wuhan University, Wuhan 430071, China. Electronic address: zengxiantao1128@163.com.
authors: Xian-Tao
authors: XT
authors: Zeng
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D049109:Cell Proliferation; D015536:Down-Regulation / Q000235:genetics*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D061986:MCF-7 Cells; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D011379:Prognosis; D016016:Proportional Hazards Models; D016019:Survival Analysis
chemical_list: D035683:MicroRNAs; C531408:mirn199 microRNA, human
keywords: Breast cancer; MiR-199b-5p; Prognosis