title: SFRP1 and SFRP2 suppress the transformation and invasion abilities of cervical cancer cells through Wnt signal pathway.
abstract: OBJECTIVE
  Aberrant activation of the Wnt/beta-catenin signaling pathway is common in human cancers, including cervical cancer. The secreted frizzled-related proteins (SFRPs) function as Wnt antagonists and play important implications in carcinogenesis. Recently, we have shown that SFRP1 and SFRP2 are frequently downregulated through promoter hypermethylation. However, the function of SFRP1 and SFRP2 in cervical cancer remains unclear.
  
  
  METHODS
  To improve our understanding of the role of SFRP1 and SFRP2 in cervical cancer cells, we use overexpression or shRNA approach in cervical cancer cell lines.
  
  
  RESULTS
  Restoration of the expression of SFRP1 and SFRP2 attenuated Wnt signaling in CaSki cells, decreased abnormal accumulation of free beta-catenin in the nucleus, and suppressed cancer cell growth. In addition, different statuses of beta-catenin accumulation in the cytoplasm of CaSki or HeLa3rd cells were observed, suggesting that different Wnt pathways are executed. Furthermore, we demonstrated that SFRP1 and SFRP2 enhance the expression of the epithelial marker E-cadherin, through inhibition of the expression of SLUG, TWIST and SNAIL, three transcription factors involved in the epithelial mesenchymal transition (EMT) program. Finally, in a xenograft animal model, we showed that SFRP1 suppresses tumorigenicity of cancer cells in vivo.
  
  
  CONCLUSIONS
  Taken together, these data strongly suggest that epigenetic silencing of SFRP genes leads to oncogenic activation of the Wnt pathway and contributes to cervical cancer progression through the EMT program.
authors.affiliation: Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Ming-Tzeung
authors.initials: MT
authors.lastname: Chung
authors.forename: Hung-Cheng
authors.initials: HC
authors.lastname: Lai
authors.forename: Huey-Kang
authors.initials: HK
authors.lastname: Sytwu
authors.forename: Ming-De
authors.initials: MD
authors.lastname: Yan
authors.forename: Yu-Lueng
authors.initials: YL
authors.lastname: Shih
authors.forename: Cheng-Chang
authors.initials: CC
authors.lastname: Chang
authors.forename: Mu-Hsien
authors.initials: MH
authors.lastname: Yu
authors.forename: Hang-Seng
authors.initials: HS
authors.lastname: Liu
authors.forename: Da-Wei
authors.initials: DW
authors.lastname: Chu
authors.forename: Ya-Wen
authors.initials: YW
authors.lastname: Lin
mesh_terms: D000818:Animals; D048708:Cell Growth Processes / Q000235:genetics; D045744:Cell Line, Tumor; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D016147:Genes, Tumor Suppressor; D006367:HeLa Cells; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000096:biosynthesis / Q000235:genetics*; D008565:Membrane Proteins / Q000096:biosynthesis / Q000235:genetics*; D051379:Mice; D016513:Mice, SCID; D009361:Neoplasm Invasiveness; D034741:RNA, Small Interfering / Q000235:genetics; D015398:Signal Transduction; D014162:Transfection; D002583:Uterine Cervical Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D051153:Wnt Proteins / Q000378:metabolism*; D051176:beta Catenin / Q000378:metabolism; D000094742:Secreted Frizzled-Related Proteins
chemical_list: D036341:Intercellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D034741:RNA, Small Interfering; D051153:Wnt Proteins; D051176:beta Catenin; C117636:SFRP1 protein, human; D000094742:Secreted Frizzled-Related Proteins; C109618:SFRP2 protein, human