title: The E-cadherin repressor slug and progression of human extrahepatic hilar cholangiocarcinoma.
abstract: OBJECTIVE
  This study explored the expression and function of Slug in human extrahepatic hilar cholangiocarcinoma (EHC) to identify its role in tumor progression.
  
  
  METHODS
  The expression of Snail and Slug mRNA in 52 human tissue samples of EHC was investigated. The mRNA of Snail and Slug were quantified using reverse transcriptase-PCR, and correlations with E-cadherin expression and clinicopathological factors were investigated. We then investigated transfection of Slug cDNA in endogenous E-cadherin-positive human EHC FRH0201 cells, selectively induced the loss of E-cadherin protein expression, and then small interfering RNA (siRNA) for inhibition of Slug expression in endogenous Slug-positive human EHC QBC939 cells, selectively induced the loss of Slug protein expression. A Boyden chamber transwell assay was used for invasion.
  
  
  RESULTS
  Slug mRNA was overexpressed in 18 cases (34.6%) of EHC compared with adjacent noncancerous tissue. E-Cadherin protein expression determined in the same 52 cases by immunohistochemistry was significantly down-regulated in those cases with Slug mRNA overexpression (P = 0.0001). The tumor and nontumor ratio of Slug mRNA was correlated with nodal metastasis(p = 0.0102), distant metastasis (p = 0.0001)and Survival time(p = 0.0443). However, Snail mRNA correlated with neither E-cadherin expression nor tumor invasiveness. By inhibiting Slug expression by RNA interference, we found that reduced Slug levels upregulated E-cadherin and decreased invasion in QBC939 cell. When the QBC939 cells was infected with Slug cDNA,, significant E-cadherin was downregulated and increased invasion in QBC939 cell.
  
  
  CONCLUSIONS
  The results suggested that Slug expression plays an important role in both the regulation of E-cadherin expression and in the acquisition of invasive potential in human EHC. Slug is possibly a potential target for an antitumor therapy blocking the functions of invasion and metastasis in human EHCs.
authors.affiliation: General Surgery, the Affiliated Hospital of medical College, Qingdao University, Qing dao, Shandong Province, 266003, China. wlsdermyy@163.com
authors.forename: Ke-jun
authors.initials: KJ
authors.lastname: Zhang
authors.forename: Dong-sheng
authors.initials: DS
authors.lastname: Wang
authors.forename: Shao-yan
authors.initials: SY
authors.lastname: Zhang
authors.forename: Xue-long
authors.initials: XL
authors.lastname: Jiao
authors.forename: Chun-wei
authors.initials: CW
authors.lastname: Li
authors.forename: Xin-sheng
authors.initials: XS
authors.lastname: Wang
authors.forename: Qin-chao
authors.initials: QC
authors.lastname: Yu
authors.forename: Hai-ning
authors.initials: HN
authors.lastname: Cui
mesh_terms: D000368:Aged; D001650:Bile Duct Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D017734:Bile Ducts, Extrahepatic / Q000378:metabolism / Q000473:pathology*; D015153:Blotting, Western; D015820:Cadherins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D002448:Cell Adhesion; D002465:Cell Movement; D018281:Cholangiocarcinoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008207:Lymphatic Metastasis; D008297:Male; D011379:Prognosis; D012333:RNA, Messenger / Q000235:genetics; D012189:Retrospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000071250:Snail Family Transcription Factors; D015996:Survival Rate; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014407:Tumor Cells, Cultured
chemical_list: D015820:Cadherins; D012333:RNA, Messenger; C000604407:SNAI1 protein, human; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors