Expression of cyclooxygenase-2 and its relationship to p53 accumulation in ovarian adenocarcinomas.
To investigate cyclooxygenase-2 (COX-2) expression and its relationship to p53 accumulation in ovarian adenocarcinomas, COX-2 and p53 protein expressions were examined by immunohistochemistry in 86 ovarian adenocarcinomas and six normal ovaries. In addition, COX-2 mRNA expression level was examined by semi-quantitative PCR in 36 ovarian adenocarcinomas. Neither COX-2 expression nor p53 accumulation were detected in normal ovarian surface epithelium or germinal inclusion cyst epithelial cells. In contrast, COX-2 protein expression was detected in 31.4% of adenocarcinomas, and p53 protein accumulation was found in 30.2% of adenocarcinomas. A significantly higher COX-2 expression rate was observed in endometrioid adenocarcinomas than in either mucinous (p=0.019) or clear cell (p=0.021) adenocarcinomas, and a significantly higher p53 accumulation rate was observed in serous adenocarcinomas compared to clear cell adenocarcinomas (p=0.015). p53 accumulation correlated with advanced clinical stage (stage I vs. stage II/III/IV: p=0.007), whereas no correlation was found between COX-2 expression and clinical stage. There was a significant positive correlation between COX-2 expression and p53 accumulation status (p=0.003). Log-rank testing showed that p53 accumulation was significantly correlated with poor patient survival (p=0.004), whereas no correlation was found between COX-2 expression and survival. COX-2 mRNA expression was detected in 72.2% of ovarian adenocarcinomas, and a significant correlation between COX-2 mRNA expression status and immunoreactivity (p=0.023) was observed. These results suggest that COX-2 expression might play an important role in ovarian cancer development and that COX-2 expression in ovarian adenocarcinomas is frequently associated with p53 protein accumulation. COX-2 overexpression in ovarian cancer cells might partly be caused by dysfunctional p53.
Shigemasa
Kazushi
K
Department of Obstetrics and Gynecology, Hiroshima University School of Medicine, Hiroshima 734-8551, Japan. kazu@hiroshima-u.ac.jp
Tian
Xiurong
X
Gu
Lijun
L
Shiroyama
Yuko
Y
Nagai
Nobutaka
N
Ohama
Koso
K
D000230:Adenocarcinoma / Q000201:enzymology* / Q000235:genetics / Q000517:prevention & control; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000627:therapeutic use; D005260:Female; D016158:Genes, p53; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000032:analysis* / Q000235:genetics; D008565:Membrane Proteins; D009154:Mutation; D010051:Ovarian Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000517:prevention & control; D016133:Polymerase Chain Reaction; D011451:Prostaglandin-Endoperoxide Synthases / Q000032:analysis* / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D007527:Isoenzymes; D008565:Membrane Proteins; D012333:RNA, Messenger; D016159:Tumor Suppressor Protein p53; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases