title: Methylation of TFPI-2 is an early event of esophageal carcinogenesis.
abstract: OBJECTIVE
  To explore the epigenetic changes and the function of TFPI-2 in esophageal cancer.
  
  
  METHODS
  Nine esophageal cancer cell lines, nine normal esophageal mucosa, 60 esophageal dysplasia and 106 advanced esophageal cancer samples were included in this study. TFPI-2 methylation was examined by methylation-specific PCR. TFPI-2 expression was evaluated by immunohistochemistry in tissue samples. The effect of TFPI-2 on proliferation, apoptosis, invasion and migration was analyzed by colony formation assay, western blot assay, transwell assay and flow cytometric analysis.
  
  
  RESULTS
  TFPI-2 expression was regulated by promoter region hypermethylation in human esophageal cancer cell lines, and TFPI-2 expression is inversely correlated with methylation in primary cancer. Methylation was found in 28.2, 33.3 and 33.3% of grade 1, 2 and 3 esophageal dysplasia, and 67% of primary esophageal cancer, but no methylation was found in normal mucosa. Methylation is significantly related to tumor differentiation. Inhibition of invasion, migration, colony formation and proliferation, and induction of apoptosis occurred with the restoration of TFPI-2 expression in the KYSE70 cell line.
  
  
  CONCLUSIONS
  TFPI-2 is frequently methylated in esophageal cancer with a progression tendency. TFPI-2 is a potential tumor suppressor in esophageal cancer.
authors.affiliation: Department of Gastroenterology & Hepatology, Chinese People's Liberation Army General Hospital, 28 Fuxing Road, Beijing 100853, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Jia
authors.forename: Yunsheng
authors.initials: Y
authors.lastname: Yang
authors.forename: Malcolm V
authors.initials: MV
authors.lastname: Brock
authors.forename: Baoping
authors.initials: B
authors.lastname: Cao
authors.forename: Qimin
authors.initials: Q
authors.lastname: Zhan
authors.forename: Yazhuo
authors.initials: Y
authors.lastname: Li
authors.forename: Yuanzi
authors.initials: Y
authors.lastname: Yu
authors.forename: James G
authors.initials: JG
authors.lastname: Herman
authors.forename: Mingzhou
authors.initials: M
authors.lastname: Guo
mesh_terms: D000328:Adult; D000368:Aged; D017209:Apoptosis; D059447:Cell Cycle Checkpoints; D045744:Cell Line, Tumor; D002465:Cell Movement; D002471:Cell Transformation, Neoplastic / Q000235:genetics; D019175:DNA Methylation; D004938:Esophageal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009092:Mucous Membrane / Q000378:metabolism; D009367:Neoplasm Staging; D011401:Promoter Regions, Genetic
chemical_list: D006023:Glycoproteins; C021240:tissue-factor-pathway inhibitor 2