title: Gastric adenocarcinoma has a unique microRNA signature not present in esophageal adenocarcinoma.
abstract: BACKGROUND
  MicroRNAs (miRNAs) play critical roles in tumor development and progression. The finding that a single miRNA can regulate hundreds of genes places miRNAs at critical hubs of signaling pathways. For the current study, the authors investigated the miRNA expression profile of gastric adenocarcinomas and compared it with esophageal adenocarcinomas to better identify a unique miRNA signature of gastric adenocarcinoma.
  
  
  METHODS
  miRNA expression profiles were obtained using 2 different proprietary microarray platforms on primary gastric adenocarcinoma tissue samples. The cross comparison of results identified 17 up-regulated miRNAs and 12 down-regulated miRNAs that overlapped in both platforms. Quantitative real-time polymerase chain reaction was performed for independent validation of a representative set of 8 miRNAs in gastric and esophageal adenocarcinomas compared with normal gastric mucosa or esophageal mucosa, respectively.
  
  
  RESULTS
  The deregulation of miR-146b-5p, miR-375, miR-148a, miR-31, and miR-451 was associated significantly with gastric adenocarcinomas. Conversely, deregulation of miR-21 (up-regulation) and miR-133b (down-regulation) was detectable in both gastric and esophageal adenocarcinomas. It was noteworthy that miR-200a was significantly down-regulated in gastric adenocarcinoma samples (P = .04) but was up-regulated in esophageal adenocarcinoma samples (P = .001). In addition, the expression level of miR-146b-5p displayed a strong correlation with the tumor stage of gastric cancer.
  
  
  CONCLUSIONS
  Gastric adenocarcinoma displayed a unique miRNA signature that distinguished it from esophageal adenocarcinoma. This specific signature may reflect differences in the etiology and/or molecular signaling in these 2 closely related cancers. The current findings suggest important miRNA candidates that can be investigated for their biological functions and for their possible diagnostic, prognostic, and therapeutic role in gastric adenocarcinoma.
authors: Department of Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
authors: Zheng
authors: Z
authors: Chen
authors: Rama
authors: R
authors: Saad
authors: Peilin
authors: P
authors: Jia
authors: DunFa
authors: D
authors: Peng
authors: Shoumin
authors: S
authors: Zhu
authors: M Kay
authors: MK
authors: Washington
authors: Zhongming
authors: Z
authors: Zhao
authors: Zekuan
authors: Z
authors: Xu
authors: Wael
authors: W
authors: El-Rifai
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics*; D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D018450:Disease Progression; D004938:Esophageal Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D035683:MicroRNAs / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D009367:Neoplasm Staging; D020411:Oligonucleotide Array Sequence Analysis; D011379:Prognosis; D060888:Real-Time Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; D035683:MicroRNAs