title: Identification of downstream metastasis-associated target genes regulated by LSD1 in colon cancer cells.
abstract: OBJECTIVE
  This study aims to identify downstream target genes regulated by lysine-specific demethylase 1 (LSD1) in colon cancer cells and investigate the molecular mechanisms of LSD1 influencing invasion and metastasis of colon cancer.
  
  
  METHODS
  We obtained the expression changes of downstream target genes regulated by small-interfering RNA-LSD1 and LSD1-overexpression via gene expression profiling in two human colon cancer cell lines. An Affymetrix Human Transcriptome Array 2.0 was used to identify differentially expressed genes (DEGs). We screened out LSD1-target gene associated with proliferation, metastasis, and invasion from DEGs via Gene Ontology and Pathway Studio. Subsequently, four key genes (CABYR, FOXF2, TLE4, and CDH1) were computationally predicted as metastasis-related LSD1-target genes. ChIp-PCR was applied after RT-PCR and Western blot validations to detect the occupancy of LSD1-target gene promoter-bound LSD1.
  
  
  RESULTS
  A total of 3633 DEGs were significantly upregulated, and 4642 DEGs were downregulated in LSD1-silenced SW620 cells. A total of 4047 DEGs and 4240 DEGs were upregulated and downregulated in LSD1-overexpressed HT-29 cells, respectively. RT-PCR and Western blot validated the microarray analysis results. ChIP assay results demonstrated that LSD1 might be negative regulators for target genes CABYR and CDH1. The expression level of LSD1 is negatively correlated with mono- and dimethylation of histone H3 lysine4(H3K4) at LSD1- target gene promoter region. No significant mono-methylation and dimethylation of H3 lysine9 methylation was detected at the promoter region of CABYR and CDH1.
  
  
  CONCLUSIONS
  LSD1- depletion contributed to the upregulation of CABYR and CDH1 through enhancing the dimethylation of H3K4 at the LSD1-target genes promoter. LSD1- overexpression mediated the downregulation of CABYR and CDH1expression through decreasing the mono- and dimethylation of H3K4 at LSD1-target gene promoter in colon cancer cells. CABYR and CDH1 might be potential LSD1-target genes in colon carcinogenesis.
authors.affiliation: Department of Gastrointestinal Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Gastrointestinal Surgery, Guizhou Provincial People's Hospital, Guiyang, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Ding
authors.affiliation: Department of Gastrointestinal Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
authors.forename: Ziwei
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Mini-invasive Surgery, Guiyang Hospital of Guizhou Aviation Industry Group, Guiyang, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Department of Mini-invasive Surgery, Guiyang Hospital of Guizhou Aviation Industry Group, Guiyang, China.
authors.forename: Xuejian
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Gastrointestinal Surgery The First People's Hospital of Guiyang, Guiyang, China.
authors.forename: Jiyi
authors.initials: J
authors.lastname: Du
mesh_terms: D015703:Antigens, CD; D017209:Apoptosis; D014408:Biomarkers, Tumor / Q000235:genetics*; D015820:Cadherins / Q000235:genetics; D002135:Calcium-Binding Proteins / Q000235:genetics; D049109:Cell Proliferation; D003110:Colonic Neoplasms / Q000235:genetics* / Q000473:pathology*; D019175:DNA Methylation; D051858:Forkhead Transcription Factors / Q000235:genetics; D020869:Gene Expression Profiling; D056466:Histone Demethylases / Q000235:genetics*; D006657:Histones / Q000235:genetics; D006801:Humans; D009362:Neoplasm Metastasis; D009687:Nuclear Proteins / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D010750:Phosphoproteins / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics; D014407:Tumor Cells, Cultured
chemical_list: D015703:Antigens, CD; D014408:Biomarkers, Tumor; C448922:CABYR protein, human; C513384:CDH1 protein, human; D015820:Cadherins; D002135:Calcium-Binding Proteins; C486413:FOXF2 protein, human; D051858:Forkhead Transcription Factors; D006657:Histones; D009687:Nuclear Proteins; D010750:Phosphoproteins; D012097:Repressor Proteins; C465817:TLE4 protein, human; D056466:Histone Demethylases; C495195:KDM1A protein, human
keywords: LSD1; colon cancer; epigenomics; gene expression profiling; target gene