title: Reduced expression of circulating microRNA-218 in gastric cancer and correlation with tumor invasion and prognosis.
abstract: OBJECTIVE
  To investigate the expression of microRNA-218 (miR-218) in serum from gastric cancer patients and its relationship with clinicopathological characteristics.
  
  
  METHODS
  A total of 68 patients with pathologically diagnosed gastric cancer and 56 healthy individuals were recruited to this study. The expression of miR-218 was detected in the serum of gastric cancer patients and healthy individuals by quantitative real-time polymerase chain reaction. The clinical data were collected and analyzed by statistical software.
  
  
  RESULTS
  miR-218 was reduced significantly in the serum of gastric cancer patients compared to healthy individuals (1.15 ± 0.08 vs 0.37 ± 0.023; P = 0.026). In the gastric cancer group, serum expression of miR-218 was lower in patients with metastasis and poorly differentiated cancer compared with non-metastatic and well-differentiated cancer (0.19 ± 0.011 vs 0.45 ± 0.021, P = 0.031 and 0.21 ± 0.019 vs 0.49 ± 0.021, P = 0.025). Serum miR-218 was found to be significantly associated with gastric cancer metastasis (P = 0.003), tumor T stage (P = 0.018) and tumor grade (P = 0.012). Low serum expression of miR-218 was related to an increase in the stage of gastric cancer. The expression level of miR-218 in the serum was correlated with the 3-year survival. Ninety-seven percent of patients with a high level of miR-218 expression survived for 3 years, while only 54% of those with low miR-218 expression survived.
  
  
  CONCLUSIONS
  miR-218 is deregulated in gastric cancer patients and is strongly correlated with tumor stage, grade and metastasis. Serum expression of miR-218 may be a prognostic marker.
authors.affiliation: Shi-Yong Xin, Department of Urology, First Affiliated Hospital of Henan University of Science and Technology, Luoyang 471003, Henan Province, China.
authors.forename: Shi-Yong
authors.initials: SY
authors.lastname: Xin
authors.affiliation: Shi-Yong Xin, Department of Urology, First Affiliated Hospital of Henan University of Science and Technology, Luoyang 471003, Henan Province, China.
authors.forename: Xiao-Shan
authors.initials: XS
authors.lastname: Feng
authors.affiliation: Shi-Yong Xin, Department of Urology, First Affiliated Hospital of Henan University of Science and Technology, Luoyang 471003, Henan Province, China.
authors.forename: Li-Qing
authors.initials: LQ
authors.lastname: Zhou
authors.affiliation: Shi-Yong Xin, Department of Urology, First Affiliated Hospital of Henan University of Science and Technology, Luoyang 471003, Henan Province, China.
authors.forename: Jun-Jun
authors.initials: JJ
authors.lastname: Sun
authors.affiliation: Shi-Yong Xin, Department of Urology, First Affiliated Hospital of Henan University of Science and Technology, Luoyang 471003, Henan Province, China.
authors.forename: Xiao-Le
authors.initials: XL
authors.lastname: Gao
authors.affiliation: Shi-Yong Xin, Department of Urology, First Affiliated Hospital of Henan University of Science and Technology, Luoyang 471003, Henan Province, China.
authors.forename: Guo-Liang
authors.initials: GL
authors.lastname: Yao
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood*; D016022:Case-Control Studies; D002454:Cell Differentiation; D015536:Down-Regulation; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D035683:MicroRNAs / Q000097:blood*; D008875:Middle Aged; D060787:Neoplasm Grading; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D016016:Proportional Hazards Models; D060888:Real-Time Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000097:blood* / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D013997:Time Factors
chemical_list: D014408:Biomarkers, Tumor; C547471:MIRN218 microRNA, human; D035683:MicroRNAs
keywords: Gastric cancer; Invasion; Prognosis; microRNA-218