title: Aberrant expression of metastasis-inducing proteins in ectopic and matched eutopic endometrium of women with endometriosis: implications for the pathogenesis of endometriosis.
abstract: BACKGROUND
  Endometriosis is a metastatic disease without obvious tumorigenesis. Expression of S100P, S100A4, osteopontin (OPN) or anterior gradient homologue 2 (AGR2) proteins can induce metastasis but fail to induce tumorigenesis per se. We now explore whether this group of metastasis-inducing proteins (MIPs) are associated with the pathogenesis of endometriosis.
  
  
  METHODS
  Eutopic endometrial biopsies were taken from 73 women (35 fertile women without endometriosis and 38 women with surgically diagnosed endometriosis). Ectopic endometriotic lesions were collected from eight of the women with endometriosis. The expression of MIPs at the cellular level was evaluated by immunohistochemistry and the presence of these proteins in the endometrial tissues was verified by western blotting and their gene expression was confirmed by RT-PCR.
  
  
  RESULTS
  All four MIPs were immunolocated in the endometrium of control women and S100P, AGR2 and OPN showed a cyclical variation. Proliferative phase eutopic endometrium of both groups showed a similar staining pattern for all MIPs, whereas secretory phase endometrium showed a differential expression between controls and cases. The secretory phase endometrial immunostaining of controls showed weak stromal and perivascular AGR2, and decreased stromal and glandular S100P. In contrast, immunostaining for all MIPs was increased in the late secretory endometrial samples of women with endometriosis and intense immunostaining was seen for S100A4 in the stroma (P< 0.05) and for S100P (P< 0.001) and AGR2 (P< 0.0001) in both glands and stroma (P< 0.001). All active peritoneal endometriotic lesions showed strong immunostaining for each of the MIPs studied.
  
  
  CONCLUSIONS
  We propose that these MIPs enhance endometrial cell invasiveness and contribute to the establishment of ectopic endometriotic deposits after retrograde menstruation.
authors.affiliation: Department for Women's and Children's Health, Institute of Translational Medicine, University of Liverpool, Liverpool, UK. dharani.hapangama@liverpool.ac.uk
authors.forename: D K
authors.initials: DK
authors.lastname: Hapangama
authors.forename: R S
authors.initials: RS
authors.lastname: Raju
authors.forename: A J
authors.initials: AJ
authors.lastname: Valentijn
authors.forename: D
authors.initials: D
authors.lastname: Barraclough
authors.forename: A
authors.initials: A
authors.lastname: Hart
authors.forename: M A
authors.initials: MA
authors.lastname: Turner
authors.forename: A
authors.initials: A
authors.lastname: Platt-Higgins
authors.forename: R
authors.initials: R
authors.lastname: Barraclough
authors.forename: P S
authors.initials: PS
authors.lastname: Rudland
mesh_terms: D000293:Adolescent; D000328:Adult; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004715:Endometriosis / Q000209:etiology* / Q000378:metabolism* / Q000473:pathology; D004717:Endometrium / Q000378:metabolism* / Q000473:pathology; D042783:Endothelial Cells / Q000378:metabolism / Q000473:pathology; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D008597:Menstrual Cycle / Q000378:metabolism*; D008599:Menstruation Disturbances / Q000503:physiopathology; D008875:Middle Aged; D009088:Mucoproteins; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D015513:Oncogene Proteins; D053495:Osteopontin / Q000235:genetics / Q000378:metabolism; D010532:Peritoneal Diseases / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D000071999:S100 Calcium-Binding Protein A4; D009418:S100 Proteins / Q000235:genetics / Q000378:metabolism*; D017154:Stromal Cells / Q000378:metabolism / Q000473:pathology; D055815:Young Adult
chemical_list: C502296:AGR2 protein, human; D002135:Calcium-Binding Proteins; D009088:Mucoproteins; D009363:Neoplasm Proteins; D015513:Oncogene Proteins; D011506:Proteins; D012333:RNA, Messenger; D000071999:S100 Calcium-Binding Protein A4; D009418:S100 Proteins; C103003:S100P protein, human; D053495:Osteopontin; C077591:S100A4 protein, human