title: Downregulation of reversion-inducing-cysteine-rich protein with Kazal motifs (RECK) is associated with enhanced expression of matrix metalloproteinases and cholangiocarcinoma metastases.
abstract: BACKGROUND
  Reversion-inducing-cysteine-rich protein with Kazal motifs (RECK) has been implicated in the attenuation of tumor metastasis by negatively regulating metalloproteinase (MMP) levels. RECK gene expression is downregulated in many solid tumors, with this downregulation being associated with poor prognosis. This study evaluated the role of RECK in cholangiocarcinoma (CCA).
  
  
  METHODS
  The expression of RECK, MMP-2, and MMP-9 in paraffin sections of hamster and human CCA specimens was analyzed by immunohistochemistry. Functional analysis of RECK was performed in RECK small interfering (si) RNA knockdown CCA cell lines. The effect of aspirin on RECK status and function was evaluated using Western blotting, gelatin zymography, invasion and proliferation assays, and PhosphoELISArray analysis of Ras downstream mediators.
  
  
  RESULTS
  Hamster tissues showed high RECK expression in hyperplastic biliary duct epithelia, low RECK expression in precancerous lesions, and no RECK expression in CCA. In human specimens, RECK was highly expressed in normal biliary cells, whereas intrahepatic CCA showed low levels of expression. Downregulation of RECK was correlated with tumor metastasis (P < 0.01) and shorter patient survival (P < 0.02). RECK expression levels were inversely correlated with MMP-2 and MMP-9 expression (P < 0.05). SiRNA RECK-depleted M139 CCA cells exhibited increased MMP-2/-9 gelatinase activities and invasiveness. Aspirin (500 μM) demonstrated myriad effects in human CCA cell lines, including growth suppression, reduced phosphorylation of Akt/Erk/c-Jun, elevation of RECK expression, inhibition of MMP-2/MMP-9 activity, and enhanced invasiveness.
  
  
  CONCLUSIONS
  RECK functions as a metastasis suppressor in CCA; upregulation of RECK expression could provide a potential therapy to improve the prognosis of this type of cancer.
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. nisana@kku.ac.th
authors.forename: N
authors.initials: N
authors.lastname: Namwat
authors.forename: J
authors.initials: J
authors.lastname: Puetkasichonpasutha
authors.forename: W
authors.initials: W
authors.lastname: Loilome
authors.forename: P
authors.initials: P
authors.lastname: Yongvanit
authors.forename: A
authors.initials: A
authors.lastname: Techasen
authors.forename: A
authors.initials: A
authors.lastname: Puapairoj
authors.forename: B
authors.initials: B
authors.lastname: Sripa
authors.forename: W
authors.initials: W
authors.lastname: Tassaneeyakul
authors.forename: N
authors.initials: N
authors.lastname: Khuntikeo
authors.forename: S
authors.initials: S
authors.lastname: Wongkham
mesh_terms: D000818:Animals; D001241:Aspirin / Q000494:pharmacology; D001650:Bile Duct Neoplasms / Q000235:genetics* / Q000473:pathology; D001653:Bile Ducts, Intrahepatic / Q000473:pathology; D045744:Cell Line, Tumor; D018281:Cholangiocarcinoma / Q000235:genetics* / Q000473:pathology; D006224:Cricetinae; D015536:Down-Regulation; D005260:Female; D058851:GPI-Linked Proteins / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D055785:Gene Knockdown Techniques; D006801:Humans; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism; D008875:Middle Aged; D009362:Neoplasm Metastasis; D034741:RNA, Small Interfering / Q000008:administration & dosage; D013045:Species Specificity; D015996:Survival Rate
chemical_list: D058851:GPI-Linked Proteins; C115460:RECK protein, human; D034741:RNA, Small Interfering; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D001241:Aspirin