title: A microRNA gene signature for identification of lung cancer.
abstract: BACKGROUND
  Lung cancer is the leading cause of cancer deaths worldwide, compounded by late diagnosis. MicroRNAs (miRNA) are recently discovered short, noncoding genes that play essential roles in tissue differentiation during normal development and tumorigenesis. miRNA profiles across all histologic grades can provide a reliable and standardized method for the identification of lung cancer.
  
  
  METHODS
  A microRNA lung cancer dataset was analyzed. Differentially expressed microRNAs were obtained post-normalization of data using t-test (p < 0.01). The data for differentially expressed microRNAs were processed using K-nearest neighbors classification method to obtain unique miRNAs expression patterns. The predicted mRNA targets were identified using TargetScan and the molecular functions associated with the predicted targets were retrieved from the Gene Ontology Consortium and represented using GO IDs in a directed acyclic graph.
  
  
  RESULTS
  The results indicate that lung cancer samples can be classified using a small panel of 19 unique microRNAs (8 down-regulated and 11 up-regulated) with over 85% classification accuracy. Furthermore, using classical enrichment analysis, this study identified 66 molecular function groups which are potentially the functional signaling pathways altered by these differentially expressed microRNAs.
  
  
  CONCLUSIONS
  We identified a microRNA gene signature representative of functioning as a diagnostic biomarker for lung cancer. These findings can potentially form the basis for the development of a standardized diagnostic assay that can be used for early diagnosis of lung cancer equally well from resection specimens and cytology samples.
authors.affiliation: Department of Thoracic Surgery, Chinese PLA General Hospital, Beijing, China.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Xue
authors.affiliation: Department of Thoracic Surgery, Chinese PLA General Hospital, Beijing, China.
authors.forename: Jiaxin
authors.initials: J
authors.lastname: Wen
authors.affiliation: Department of Thoracic Surgery, Chinese PLA General Hospital, Beijing, China.
authors.forename: Xiangyang
authors.initials: X
authors.lastname: Chu
authors.affiliation: Department of Special Medical Treatment - Respiratory Disease, Beijing Shijitan Hospital, Capital Medical University, Beijing, China; Department of Respiratory Diseases of Chinese PLA General Hospital, Beijing, China. Electronic address: xinyingxue2010@163.com.
authors.forename: Xinying
authors.initials: X
authors.lastname: Xue
mesh_terms: D030541:Databases, Genetic; D015536:Down-Regulation; D020869:Gene Expression Profiling; D063990:Gene Ontology; D006801:Humans; D008175:Lung Neoplasms / Q000145:classification* / Q000235:genetics*; D035683:MicroRNAs / Q000032:analysis*; D059467:Transcriptome; D015854:Up-Regulation
chemical_list: D035683:MicroRNAs
keywords: Gene; Gene signature; Identification cancer; Lung cancer; MicroRNA