title: Expression of the epidermal growth factor system in eutopic endometrium from women with endometriosis differs from that in endometrium from healthy women.
abstract: BACKGROUND
  The epidermal growth factor (EGF) system comprises four receptors, HER1-4, and several ligands, and is cyclically expressed in endometrium from healthy fertile women. Our aim is to identify differences in expression of the EGF system between endometriotic and normal endometrium.
  
  
  METHODS
  We previously examined the EGF system in endometrial samples from healthy women (n = 14). Here we examine samples from endometrium (n = 23), endometriomas (n = 10) and peritoneal endometriosis (n = 9) from women with endometriosis (n = 23). mRNA expression of receptors and ligands from the EGF system was analyzed by real-time PCR, and proteins were localized by immunohistochemistry.
  
  
  RESULTS
  Endometrial mRNA for HER1-3 was high compared with our previous findings in healthy endometrium, whereas HER4 and the ligands were unchanged. Endometriomas show lower expression of HER1-3 and no HER4 expression. Significant differences were demonstrated in late secretory phase for HER1 and HER2 and in the proliferative phase for HER3 compared to healthy women. Immunohistochemically, HER2 was identified in all samples, predominately in glands and surface epithelium. In a few glands, HER2 was in both cytoplasm and cell membrane.
  
  
  CONCLUSIONS
  We report quantitative and qualitative differences in the EGF system in endometriotic eutopic endometrium compared to endometrium from healthy individuals.
authors.affiliation: Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Ejskjaer
authors.forename: Boe Sandahl
authors.initials: BS
authors.lastname: Sorensen
authors.forename: Steen Seier
authors.initials: SS
authors.lastname: Poulsen
authors.forename: Ole
authors.initials: O
authors.lastname: Mogensen
authors.forename: Axel
authors.initials: A
authors.lastname: Forman
authors.forename: Ebba
authors.initials: E
authors.lastname: Nexo
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D001707:Biopsy, Needle; D016022:Case-Control Studies; D004715:Endometriosis / Q000235:genetics / Q000473:pathology* / Q000601:surgery; D004815:Epidermal Growth Factor / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005500:Follow-Up Studies; D005786:Gene Expression Regulation; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D017697:Premenopause; D011336:Probability; D012333:RNA, Messenger / Q000032:analysis*; D012016:Reference Values; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D014591:Uterine Diseases / Q000235:genetics / Q000473:pathology* / Q000601:surgery; D055815:Young Adult
chemical_list: D015415:Biomarkers; D012333:RNA, Messenger; D004815:Epidermal Growth Factor