title: Oncogene GAEC1 regulates CAPN10 expression which predicts survival in esophageal squamous cell carcinoma.
abstract: OBJECTIVE
  To identify the downstream regulated genes of GAEC1 oncogene in esophageal squamous cell carcinoma and their clinicopathological significance.
  
  
  METHODS
  The anti-proliferative effect of knocking down the expression of GAEC1 oncogene was studied by using the RNA interference (RNAi) approach through transfecting the GAEC1-overexpressed esophageal carcinoma cell line KYSE150 with the pSilencer vector cloned with a GAEC1-targeted sequence, followed by MTS cell proliferation assay and cell cycle analysis using flow cytometry. RNA was then extracted from the parental, pSilencer-GAEC1-targeted sequence transfected and pSilencer negative control vector transfected KYSE150 cells for further analysis of different patterns in gene expression. Genes differentially expressed with suppressed GAEC1 expression were then determined using Human Genome U133 Plus 2.0 cDNA microarray analysis by comparing with the parental cells and normalized with the pSilencer negative control vector transfected cells. The most prominently regulated genes were then studied by immunohistochemical staining using tissue microarrays to determine their clinicopathological correlations in esophageal squamous cell carcinoma by statistical analyses.
  
  
  RESULTS
  The RNAi approach of knocking down gene expression showed the effective suppression of GAEC1 expression in esophageal squamous cell carcinoma cell line KYSE150 that resulted in the inhibition of cell proliferation and increase of apoptotic population. cDNA microarray analysis for identifying differentially expressed genes detected the greatest levels of downregulation of calpain 10 (CAPN10) and upregulation of trinucleotide repeat containing 6C (TNRC6C) transcripts when GAEC1 expression was suppressed. At the tissue level, the high level expression of calpain 10 protein was significantly associated with longer patient survival (month) of esophageal squamous cell carcinoma compared to the patients with low level of calpain 10 expression (37.73 ± 16.33 vs 12.62 ± 12.44, P = 0.032). No significant correction was observed among the TNRC6C protein expression level and the clinocopathologcial features of esophageal squamous cell carcinoma.
  
  
  CONCLUSIONS
  GAEC1 regulates the expression of CAPN10 and TNRC6C downstream. Calpain 10 expression is a potential prognostic marker in patients with esophageal squamous cell carcinoma.
authors.affiliation: State Key Laboratory of Chirosciences, Lo Ka Chung Centre for Natural Anti-cancer Drug Development, Department of Applied Biology and Chemical Technology, the Hong Kong Polytechnic University, Hong Kong, China.
authors.forename: Dessy
authors.initials: D
authors.lastname: Chan
authors.forename: Miriam Yuen-Tung
authors.initials: MY
authors.lastname: Tsoi
authors.forename: Christina Di
authors.initials: CD
authors.lastname: Liu
authors.forename: Sau-Hing
authors.initials: SH
authors.lastname: Chan
authors.forename: Simon Ying-Kit
authors.initials: SY
authors.lastname: Law
authors.forename: Kwok-Wah
authors.initials: KW
authors.lastname: Chan
authors.forename: Yuen-Piu
authors.initials: YP
authors.lastname: Chan
authors.forename: Vinod
authors.initials: V
authors.lastname: Gopalan
authors.forename: Alfred King-Yin
authors.initials: AK
authors.lastname: Lam
authors.forename: Johnny Cheuk-On
authors.initials: JC
authors.lastname: Tang
mesh_terms: D000368:Aged; D017209:Apoptosis; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D002154:Calpain / Q000235:genetics / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D004938:Esophageal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D005260:Female; D020869:Gene Expression Profiling / Q000379:methods; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D011379:Prognosis; D016016:Proportional Hazards Models; D034622:RNA Interference; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D013997:Time Factors; D046888:Tissue Array Analysis; D014162:Transfection
chemical_list: D014408:Biomarkers, Tumor; C523388:GAEC1 protein, human; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins; C540399:TNRC6C protein, human; D002154:Calpain; C415197:calpain 10
keywords: Calpain 10; Esophageal squamous cell carcinoma; Oncogene; RNA interference; Tissue microarray