title: p21WAF1/CIP1 expression in gestational trophoblastic disease: correlation with clinicopathological parameters, and Ki67 and p53 gene expression.
abstract: BACKGROUND
  The p21WAF1/CIP1 gene mediates growth arrest by inhibiting G1 cyclin dependent kinases and has been considered as a downstream effector of the tumour suppressor gene p53.
  
  
  OBJECTIVE
  To analyse the role of p21WAF1/CIP1 in gestational trophoblastic disease.
  
  
  METHODS
  The immunohistochemical expression of p21WAF1/CIP1 gene was measured in 33 placentas, 28 partial hydatidiform moles, 54 complete hydatidiform moles, and 13 choriocarcinomas in paraffin wax embedded tissue. The results were correlated with p53 (DO7) and Ki67 (MIB1) immunoreactivity as well as clinical progress.
  
  
  RESULTS
  p21WAF1/CIP1 immunoreactivity was found predominantly in the nuclei of the syncytiotrophoblasts. p21WAF1/CIP1 protein expression correlated with gestational age in normal placentas (p = 0.0001) but not in hydatidiform moles (p = 0.89). Complete hydatidiform moles and choriocarcinomas had a significantly higher p21WAF1/CIP1 expression compared with normal placentas and partial hydatidiform moles (p < 0.001); there was no difference between placentas and partial hydatidiform moles. No correlation between p21WAF1/CIP1 expression and either the proliferation (Ki67) index (p = 0.34) or p53 protein accumulation (p = 0.68) was demonstrated. There was no significant difference (p > 0.05) in p21WAF1/CIP1 expression between the 17 patients who developed persistent gestational trophoblastic disease and those who did not.
  
  
  CONCLUSIONS
  This study suggests that p21WAF1/CIP1 expression in trophoblastic disease may be induced by a p53 independent pathway. The proliferative activity of gestational trophoblastic diseases might not be determined solely by the control of the cell cycle operated by p21WAF1/CIP1. p21WAF1/CIP1 expression is not an accurate prognostic indicator of gestational trophoblastic disease.
authors.affiliation: Department of Pathology, Queen Mary Hospital, University of Hong Kong. anycheun@hkucc.hku.hk
authors.forename: A N
authors.initials: AN
authors.lastname: Cheung
authors.forename: D H
authors.initials: DH
authors.lastname: Shen
authors.forename: U S
authors.initials: US
authors.lastname: Khoo
authors.forename: L C
authors.initials: LC
authors.lastname: Wong
authors.forename: H Y
authors.initials: HY
authors.lastname: Ngan
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism*; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000378:metabolism*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007124:Immunoenzyme Techniques; D019394:Ki-67 Antigen / Q000378:metabolism; D009363:Neoplasm Proteins / Q000378:metabolism*; D010920:Placenta / Q000378:metabolism; D011247:Pregnancy; D014328:Trophoblastic Neoplasms / Q000378:metabolism* / Q000473:pathology; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D014594:Uterine Neoplasms / Q000378:metabolism* / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D019394:Ki-67 Antigen; D009363:Neoplasm Proteins; D016159:Tumor Suppressor Protein p53