title: Evaluating the miR-302b and miR-145 expression in formalin-fixed paraffin-embedded samples of esophageal squamous cell carcinoma.
abstract: BACKGROUND
  MicroRNAs are involved in key cellular processes regulating, and their misregulation is linked to cancer. The miR-302-367 cluster is exclusively expressed in embryonic stem and carcinoma cells. This cluster also promotes cell reprogramming and stemness process. In contrast, miR-145 is mostly regarded as a tumor suppressor, where it regulates cellular functions such as cell division, differentiation, and apoptosis. By suppressing the main pluripotency factors (OCT4, SOX2, MYC and KLF4), miR-145 silences the self-renewal program in ESCs. Therefore, the main aim of this study is to find a potential link between the expression level of hsa-miR-302b and hsa-miR-145 with tumor vs. non-tumor as well as high-grade vs. low-grade states of the esophageal tissue samples.
  
  
  METHODS
  A total number of 40 formalin-fixed, paraffin-embedded (FFPE) samples of esophageal squamous-cell carcinoma (ESCC) were obtained, and the tumor and marginal non-tumor areas delineated and punched off by an expert pathologist. Total RNA was extracted with Trizol, and cDNA synthesized using the miRCURY LNA™ Universal RT microRNA PCR Kit. Real-time reverse transcription polymerase chain reaction (RT-PCR) assays were performed using specific LNA-primers and SYBR Green master mix.
  
  
  RESULTS
  The expression level of miR-302b failed to show any significant difference, neither between tumor and their non-tumor counterparts, nor among tumors with different grades of malignancies (p > 0.05). In contrast, miR-145 was significantly down regulated in all grades of tumor samples (p < 0.001). However, its expression level could not discriminate between different grades of malignancy (p > 0.05).
  
  
  CONCLUSIONS
  Our data revealed a significant down-regulation of miR-145 in ESCC tissue samples. Based on our ROC curve analysis data (AUC = 0.74, p < 0.001) miR-145 could be regarded as a potential tumor marker for diagnosis of esophageal cancer.
authors.affiliation: Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran. sjmowla@modares.ac.ir.
authors.forename: Mojtaba
authors.initials: M
authors.lastname: Tabrizi
authors.affiliation: Department of Medical Genetics and Molecular Medicine, Zanjan University of Medical Sciences, Zanjan, Iran.
authors.forename: Mitra
authors.initials: M
authors.lastname: Khalili
authors.affiliation: Department of Pathology and Digestive Disease Research Institute, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Vasei
authors.affiliation: Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran.
authors.forename: Nazila
authors.initials: N
authors.lastname: Nouraei
authors.affiliation: Human Genetics Department, Golestan University of Medical Sciences, Gorgan, Iran.
authors.forename: Nader
authors.initials: N
authors.lastname: Mansour Samaei
authors.affiliation: Emergency Medicine Department, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Khavanin
authors.affiliation: Student Research Committee, Shiraz Medical School, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Khajehei
authors.affiliation: Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran.
authors.forename: Seyed Javad
authors.initials: SJ
authors.lastname: Mowla
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000235:genetics*; D004938:Esophageal Neoplasms / Q000175:diagnosis / Q000235:genetics*; D000077277:Esophageal Squamous Cell Carcinoma; D006801:Humans; D000090062:Kruppel-Like Factor 4; D035683:MicroRNAs / Q000032:analysis*; D016612:Paraffin Embedding; D012372:ROC Curve; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D014408:Biomarkers, Tumor; C000715467:KLF4 protein, human; D000090062:Kruppel-Like Factor 4; C541010:MIRN145 microRNA, human; C532169:MIRN302A microRNA, human; D035683:MicroRNAs