title: Mismatch repair system in endometriotic tissue and eutopic endometrium of unaffected women.
abstract: OBJECTIVE
  To test the immunohistochemical staining pattern of some mismatch repair (MMR) system proteins in endometriotic tissue (ET) and eutopic endometrium.
  
  
  METHODS
  This was a retrospective study conducted at the Pathology and Obstetrics and Gynecology Departments of the Udine University Hospital. We analyzed 528 samples obtained from 246 patients affected by endometriosis and 71 samples from 71 patients with normal endometrium. A tissue microarray model was used to analyze the immunohistochemical expression of MMR system proteins.
  
  
  RESULTS
  Significant loss of MMR proteins was found in the stromal component of ETs. We found MSH2 to be expressed at a higher level than any other MMR system proteins in eutopic endometrium and ETs, to be significantly correlated to Ki-67 expression in both stromal and glandular components of ETs, and to be expressed at a significantly higher level in ETs than in eutopic endometrium. When considering the subgroup of endometriosis with high recurrence rate and glandular cytoplasmic staining for aurora A kinase, we found MMR proteins expressed at a significantly higher level in these ETs than in other ETs and eutopic endometrium of unaffected women.
  
  
  CONCLUSIONS
  We found significant loss of MMR proteins (known to be associated with microsatellite instability) in the stromal component of ETs. The group of ETs with glandular cytoplasmic staining for aurora A kinase had higher MMR protein expression, suggesting an increased activity of this system. Our result suggests a novel role of increased MSH2 expression in cellular proliferation of endometriosis.
authors.affiliation: Clinic of Obstetrics and Gynecology, University of Udine 33100 Udine, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Grassi
authors.affiliation: Clinic of Obstetrics and Gynecology, University of Udine 33100 Udine, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Calcagno
authors.affiliation: Institute of Pathology, University of Udine 33100 Udine, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Marzinotto
authors.affiliation: Clinic of Obstetrics and Gynecology, University of Udine 33100 Udine, Italy ; Unit of Obstetrics and Gynecology, S. Polo's Hopital 34074 Monfalcone (GO), Italy.
authors.forename: Ambrogio P
authors.initials: AP
authors.lastname: Londero
authors.affiliation: Institute of Pathology, University of Udine 33100 Udine, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Orsaria
authors.affiliation: Norwich Medical School, University of East Anglia Norwich, NR4 7TJ, United Kingdom.
authors.forename: Gioia N
authors.initials: GN
authors.lastname: Canciani
authors.affiliation: Institute of Pathology, University of Udine 33100 Udine, Italy.
authors.forename: Carlo Alberto
authors.initials: CA
authors.lastname: Beltrami
authors.affiliation: Clinic of Obstetrics and Gynecology, University of Udine 33100 Udine, Italy.
authors.forename: Diego
authors.initials: D
authors.lastname: Marchesoni
authors.affiliation: Institute of Pathology, University of Udine 33100 Udine, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Mariuzzi
mesh_terms: D064096:Aurora Kinase A / Q000032:analysis; D015415:Biomarkers / Q000032:analysis; D049109:Cell Proliferation; D053843:DNA Mismatch Repair; D004715:Endometriosis / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D004717:Endometrium / Q000737:chemistry* / Q000473:pathology; D005260:Female; D006785:Hospitals, University; D006801:Humans; D007150:Immunohistochemistry; D007558:Italy; D019394:Ki-67 Antigen / Q000032:analysis; D051718:MutS Homolog 2 Protein / Q000032:analysis*; D012042:Registries; D012189:Retrospective Studies; D015398:Signal Transduction; D017154:Stromal Cells / Q000737:chemistry / Q000473:pathology; D015854:Up-Regulation
chemical_list: D015415:Biomarkers; D019394:Ki-67 Antigen; C576917:AURKA protein, human; D064096:Aurora Kinase A; C497172:MSH2 protein, human; D051718:MutS Homolog 2 Protein
keywords: Endometriosis; MLH1; MSH2; MSH6; PMS2; aurora A kinase; microsatellite instability; mismatch repair system proteins