title: Decreased annexin I expression in prostatic adenocarcinoma and in high-grade prostatic intraepithelial neoplasia.
abstract: OBJECTIVE
  To analyse annexin I expression in prostatic carcinoma. Annexin I belongs to a family of structurally related calcium and phospholipid-binding proteins implicated in signal transduction, DNA replication, cell proliferation and apoptosis. The decreased expression of annexin I, II and VII proteins has been reported in different types of cancer.
  
  
  RESULTS
  Using immunohistochemistry, we analysed annexin I expression in 77 cases of prostatic adenocarcinoma (Gleason score 6, N = 40; Gleason scores 7-8, N = 27; and Gleason scores 9-10, N = 10) and high-grade prostatic intraepithelial neoplasia (PIN, N = 50). Immunoreactivity of annexin I in tumour cells was evaluated as negative (< 5% of cells), focally positive (5-25% of cells) or positive (> 25% of cells). In contrast to positive staining in adjacent benign prostatic epithelium, annexin I expression was decreased (focally positive) in 76% of cases of high-grade PIN (P < 0.0001) and was decreased or absent in 81% of prostatic adenocarcinomas (P < 0.0001). Annexin I expression in all higher grade tumours (Gleason scores 7-10) was only focally positive or absent.
  
  
  CONCLUSIONS
  Expression of annexin I inversely correlates with the increasing histological grade of prostatic adenocarcinoma. By showing a progressive loss of annexin I expression in high-grade PIN, intermediate-grade and high-grade cancer, our findings suggest that the loss of annexin I expression occurs early in prostatic tumorigenesis and becomes more prominent throughout tumour progression. The loss of expression of annexin I may serve as a useful marker of prostate cancer development and progression.
authors.affiliation: Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA.
authors.forename: K T
authors.initials: KT
authors.lastname: Patton
authors.forename: H M
authors.initials: HM
authors.lastname: Chen
authors.forename: L
authors.initials: L
authors.lastname: Joseph
authors.forename: X J
authors.initials: XJ
authors.lastname: Yang
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics* / Q000473:pathology*; D017305:Annexin A1 / Q000032:analysis* / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000032:analysis*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D019048:Prostatic Intraepithelial Neoplasia / Q000235:genetics* / Q000473:pathology*; D012189:Retrospective Studies
chemical_list: D017305:Annexin A1; D014408:Biomarkers, Tumor