title: Multiple differential expression networks identify key genes in rectal cancer.
abstract: BACKGROUND
  Rectal cancer is an important contributor to cancer mortality.
  
  
  OBJECTIVE
  The objective of this paper is to identify key genes across three phenotypes (fungating, polypoid and polypoid & small-ulcer) of rectal cancer based on multiple differential expression networks (DENs).
  
  
  METHODS
  Differential interactions and non-differential interactions were evaluated according to Spearman correlation coefficient (SCC) algorithm, and were selected to construct DENs. Topological analysis was performed for exploring hub genes in largest components of DENs. Key genes were denoted as intersections between nodes of DENs and rectal cancer associated genes from Genecards. Finally, we utilized hub genes to classify phenotypes of rectal cancer on the basis of support vector machines (SVM) methodology.
  
  
  RESULTS
  We obtained 19 hub genes and total 12 common key genes of three largest components of DENs, and EGFR was the common element. The SVM results revealed that hub genes could classify phenotypes, and validated feasibility of DEN methods.
  
  
  CONCLUSIONS
  We have successfully identified significant genes (such as EGFR and UBC) across fungating, polypoid and polypoid & small-ulcer phenotype of rectal cancer. They might be potential biomarkers for classification, detection and therapy of this cancer.
authors.affiliation: Department of Gastrointestinal Surgery, Affiliated Hospital of Hebei University, Baoding, Hebei, China.
authors.forename: Ri-Heng
authors.initials: RH
authors.lastname: Li
authors.affiliation: Department of Gastrointestinal Surgery, Affiliated Hospital of Hebei University, Baoding, Hebei, China.
authors.forename: Ai-Min
authors.initials: AM
authors.lastname: Zhang
authors.affiliation: Department of Blood Transfusion, Neimenggu Xinganleague People's Hospital, Wulanhaote, Inner Mongolia, China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Li
authors.affiliation: Clinical Medical College of Hebei University, Baoding, Hebei, China.
authors.forename: Tian-Yang
authors.initials: TY
authors.lastname: Li
authors.affiliation: Clinical Medical College of Hebei University, Baoding, Hebei, China.
authors.forename: Lian-Jing
authors.initials: LJ
authors.lastname: Wang
authors.affiliation: Clinical Medical College of Hebei University, Baoding, Hebei, China.
authors.forename: Hao-Ran
authors.initials: HR
authors.lastname: Zhang
authors.affiliation: Department of Gastrointestinal Surgery, Affiliated Hospital of Hebei University, Baoding, Hebei, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Li
authors.affiliation: Department of Gastrointestinal Surgery, Affiliated Hospital of Hebei University, Baoding, Hebei, China.
authors.forename: Xiong-Jie
authors.initials: XJ
authors.lastname: Jia
authors.affiliation: Department of Gastrointestinal Surgery, Affiliated Hospital of Hebei University, Baoding, Hebei, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Department of Gastrointestinal Surgery, Affiliated Hospital of Hebei University, Baoding, Hebei, China.
authors.forename: Xin-Yu
authors.initials: XY
authors.lastname: Peng
authors.affiliation: Department of Gastrointestinal Surgery, Affiliated Hospital of Hebei University, Baoding, Hebei, China.
authors.forename: Min-Di
authors.initials: MD
authors.lastname: Liu
authors.affiliation: Department of Gastrointestinal Surgery, Affiliated Hospital of Hebei University, Baoding, Hebei, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Gastrointestinal Surgery, Affiliated Hospital of Hebei University, Baoding, Hebei, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Lang
authors.affiliation: Department of Gastrointestinal Surgery, Affiliated Hospital of Hebei University, Baoding, Hebei, China.
authors.forename: Wei-Lan
authors.initials: WL
authors.lastname: Xue
authors.affiliation: Department of Gastrointestinal Surgery, Affiliated Hospital of Hebei University, Baoding, Hebei, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Gastrointestinal Surgery, Affiliated Hospital of Hebei University, Baoding, Hebei, China.
authors.forename: Yan-Yan
authors.initials: YY
authors.lastname: Wang
mesh_terms: D000951:Antigens, Neoplasm / Q000235:genetics; D014408:Biomarkers, Tumor / Q000235:genetics*; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics; D066246:ErbB Receptors / Q000235:genetics; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D054730:Protein Interaction Domains and Motifs / Q000235:genetics*; D012004:Rectal Neoplasms / Q000235:genetics* / Q000401:mortality; D015398:Signal Transduction / Q000235:genetics; D060388:Support Vector Machine
chemical_list: D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; C440529:UBC antigen; C512478:EGFR protein, human; D066246:ErbB Receptors
keywords: Rectal cancer; differential expression network; differential interactions; genes; non-differential interactions