title: Endometrium from women with and without endometriosis, and peritoneal, ovarian and bowel endometriosis, show different c-kit protein expression.
abstract: BACKGROUND
  Endometriosis is defined by the presence of endometrium outside the uterus. Changes in the expression of the proto-oncogene c-kit are associated with aggressive behaviour of both benign and malignant tumours, but there are few data on its c-kit expression in endometriosis. Here we examined c-kit expression in endometrium and endometriotic tissue.
  
  
  METHODS
  Immunohistochemistry was used for qualitative and semi-quantitative (mean+/-S.D. positive cells) analysis of c-kit expression in endometrium from women with (n=9) and without endometriosis (n=18), and in peritoneal (n=20), ovarian (n=20) and colorectal endometriosis (n=20).
  
  
  RESULTS
  Semi-quantitative c-kit expression was higher in endometrial glandular cells from women with endometriosis than from women without endometriosis (15.0+/-14.6% versus 3.9+/-7.4%, p=0.01). No difference in c-kit expression was found in qualitative analysis and according to the phase of the menstrual cycle. C-kit expression values in peritoneal, ovarian and colorectal endometriosis were 2.0+/-3.8%, 2.0+/-4.1% and 21.7+/-18.4%, respectively. Qualitative and semi-quantitative c-kit expression was higher in colorectal endometriosis than in peritoneal and ovarian endometriosis (p<0.001); no difference was found between ovarian and peritoneal endometriosis. No c-kit expression was detected in stromal cells of either endometrium or endometriotic tissue.
  
  
  CONCLUSIONS
  These results suggest that the c-kit/stem cell factor axis is involved in the pathogenesis of endometriosis. Strong c-kit protein expression was associated with invasive endometriotic lesions.
authors.affiliation: Service d'Anatomie Pathologie, Hôpital Tenon, AP-HP, 4 rue de la Chine, 75020 Paris, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Uzan
authors.forename: Annie
authors.initials: A
authors.lastname: Cortez
authors.forename: Charlotte
authors.initials: C
authors.lastname: Dufournet
authors.forename: Raffaèle
authors.initials: R
authors.lastname: Fauvet
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Siffroi
authors.forename: Emile
authors.initials: E
authors.lastname: Daraï
mesh_terms: D000328:Adult; D003106:Colon / Q000378:metabolism / Q000473:pathology; D004715:Endometriosis / Q000378:metabolism* / Q000473:pathology; D004717:Endometrium / Q000378:metabolism* / Q000473:pathology; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D010053:Ovary / Q000378:metabolism / Q000473:pathology; D010537:Peritoneum / Q000378:metabolism / Q000473:pathology; D000090063:Proto-Oncogene Mas; D019009:Proto-Oncogene Proteins c-kit / Q000096:biosynthesis*
chemical_list: C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D019009:Proto-Oncogene Proteins c-kit