title: Nuclear expression of Snail1 in borderline and malignant epithelial ovarian tumours is associated with tumour progression.
abstract: BACKGROUND
  Transcription factor Snail1 has a central role in induction of epithelial-mesenchymal transition (EMT). The aim of the present study was to elucidate the expression of Snail1 protein during epithelial ovarian tumourigenesis and to study the association of Snail1 expression with clinicopathological factors and prognosis.
  
  
  METHODS
  Epithelial and stromal fibroblast-like fusiform cells of 14 normal ovarian samples, 21 benign, 24 borderline and 74 malignant epithelial ovarian tumours were studied for Snail1 protein using immunohistochemistry.
  
  
  RESULTS
  Nuclei of surface peritoneal cells of normal ovaries (n = 14) were regarded as negative for Snail1. Nuclear expression of Snail1 protein in epithelial ovarian tumours was increased during tumour progression from precursor lesions into carcinomas both in epithelial (p = 0.006) and stromal cells (p = 0.007). Nuclei of benign tumours (n = 21) were negative for Snail1. In borderline tumours (n = 24) occasional positive epithelial cells were found in 2 (8%) samples and in 3 (13%) samples stromal cells were focally positive for Snail1. In carcinomas (n = 74) focal Snail1 staining in epithelial cells was present in 17 (23%) tumours, and in stromal cells in 18 (24%) tumours. Nuclear expression of Snail1 in epithelial or stromal cells was not associated with clinicopathological factors or prognosis.
  
  
  CONCLUSIONS
  Nuclear Snail1 expression seems to be related to tumour progression, and expression in borderline tumours indicates a role for Snail1 in early epithelial ovarian tumour development. Snail1 also appears to function more generally in tissue remodelling as positive staining was demonstrated in stromal cells.
authors.affiliation: Pathology and Forensic Medicine, Institute of Clinical Medicine, University of Kuopio, Kuopio, Finland. hanna.tuhkanen@uku.fi
authors.forename: Hanna
authors.initials: H
authors.lastname: Tuhkanen
authors.forename: Ylermi
authors.initials: Y
authors.lastname: Soini
authors.forename: Veli-Matti
authors.initials: VM
authors.lastname: Kosma
authors.forename: Maarit
authors.initials: M
authors.lastname: Anttila
authors.forename: Reijo
authors.initials: R
authors.lastname: Sironen
authors.forename: Kirsi
authors.initials: K
authors.lastname: Hämäläinen
authors.forename: Laura
authors.initials: L
authors.lastname: Kukkonen
authors.forename: Ismo
authors.initials: I
authors.lastname: Virtanen
authors.forename: Arto
authors.initials: A
authors.lastname: Mannermaa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000378:metabolism*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008875:Middle Aged; D009385:Neoplastic Processes; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D010051:Ovarian Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D009687:Nuclear Proteins; C000604407:SNAI1 protein, human; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors
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