title: Up-regulation of miR-335 predicts a favorable prognosis in esophageal squamous cell carcinoma.
abstract: BACKGROUND
  MicroRNAs (miRNAs) are noncoding RNAs that regulate multiple cellular processes during cancer progression. MiR-335 has recently been identified to be involved in tumorigenesis of several cancers such as ovarian cancer and gastric cancer. However, the regulation of miR-335 in esophageal squamous cell carcinoma (ESCC) has not been reported yet.
  
  
  METHODS
  Expression of miR-335 in tumor and their normal matched tissues was determined by quantitative real-time PCR in 67 ESCC patients and its association with overall survival of patients was analyzed by statistical analysis.
  
  
  RESULTS
  The expression level of miR-335 was reduced in malignant tissue samples in comparison to normal matched tissue (P < 0.05). It was also proved that miR-335 expression was associated with ESCC histological grade, lymph node metastasis, tumor stage and clinical stage (P < 0.05). In addition, the Kaplan-Meier survival curves revealed that low miR-335 expression was associated with poor prognosis in ESCC patients. Multivariate analysis showed that miR-335 expression was an independent prognostic marker of overall survival of ESCC patients.
  
  
  CONCLUSIONS
  The study proves for the first time that miR-335 is down regulated in a majority of ESCC patients. Our results indicate that miR-335 expression is an independent prognostic factor for patients with esophageal cancer, which might be a potential valuable biomarker for ESCC.
authors.affiliation: Department of Anesthesiology, Central Hospital of Xinxiang City Xinxiang 453000, China.
authors.forename: Bao-Jun
authors.initials: BJ
authors.lastname: Zhang
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Xinxiang Medical University Weihui 453100, China.
authors.forename: Hong-Yan
authors.initials: HY
authors.lastname: Gong
authors.affiliation: Department of Ultrasound, The First Affiliated Hospital of Xinxiang Medical University Weihui 453100, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Zheng
authors.affiliation: Department of Anesthesiology, The Second Affiliated Hospital of Zhengzhou University Zhengzhou 450014, China.
authors.forename: De-Jun
authors.initials: DJ
authors.lastname: Liu
authors.affiliation: Department of Cardology, Henan Provincial Chest Hospital Zhengzhou 450000, China.
authors.forename: Hai-Xia
authors.initials: HX
authors.lastname: Liu
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics*; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000401:mortality / Q000556:secondary; D016022:Case-Control Studies; D004938:Esophageal Neoplasms / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D000077277:Esophageal Squamous Cell Carcinoma; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D008297:Male; D035683:MicroRNAs / Q000235:genetics*; D008875:Middle Aged; D015999:Multivariate Analysis; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D016016:Proportional Hazards Models; D060888:Real-Time Polymerase Chain Reaction; D012307:Risk Factors; D013997:Time Factors; D015854:Up-Regulation
chemical_list: D014408:Biomarkers, Tumor; C556347:MIRN335 microRNA, human; D035683:MicroRNAs
keywords: esophageal squamous cell carcinoma; miR-335; prognosis; quantitative real-time PCR