Expression of COX-2 is associated with accumulation of p53 in pancreatic cancer: analysis of COX-2 and p53 expression in premalignant and malignant ductal pancreatic lesions.
OBJECTIVE
Cyclooxygenase-2 (COX-2) and tumor suppressor p53 are molecules that are linked to the oncogenesis of pancreatic cancer. COX-2 represents a key modulatory molecule in inflammation and carcinogenesis, and is known to be implicated in the positive regulation of growth and tumorigenesis. Abnormal expression of p53 is common in many human neoplasms including pancreatic cancer. Recent studies demonstrated functional interactions between p53 and COX-2. The p53-dependent upregulation of COX-2 was proposed to be another mechanism by which p53 could abate its own growth-inhibitory and apoptotic effects.


METHODS
In this study, we immunohistochemically analyzed the expression of COX-2 and p53 in 95 pancreatic resection specimens [adenocarcinomas, 95 lesions; pancreatic intraepithelial neoplasias (PanINs), 155; normal ducts, 70].


RESULTS
The expression of COX-2 increased progressively with the grade of ductal lesions (P<0.00001). A statistically significant difference of COX-2 expression between normal ducts and low-grade PanINs was revealed (P=0.0042). COX-2 overexpression was demonstrated in 82 PanINs (52.9%), and in 76 adenocarcinomas (80%). No significant correlation between the grade of adenocarcinoma and COX-2 expression was revealed (P=0.2). The expression of p53 again increased progressively with the grade of lesions (P<0.00001) with a significant increase in high-grade PanINs. A correlation between COX-2 and p53 expression levels in carcinomas was revealed (P=0.0002), and an accumulation of p53 was associated with COX-2 overexpression in premalignant and malignant ductal lesions.


CONCLUSIONS
These findings confirmed the generally accepted pancreatic cancer progression model, and supported the concept of the interactive role of COX-2 and p53 in pancreatic cancer carcinogenesis, which offers opportunities for targeted therapy and chemoprevention of pancreatic cancer using COX-2 inhibitors.
Hermanova
Marketa
M
Department of Pathology, Masaryk University and University Hospital Brno, Brno, Czech Republic. marherman@post.cz
Trna
Jan
J
Nenutil
Rudolf
R
Dite
Petr
P
Kala
Zdenek
Z
D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D021441:Carcinoma, Pancreatic Ductal / Q000378:metabolism / Q000473:pathology; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D018450:Disease Progression; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D010183:Pancreatic Ducts / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D011230:Precancerous Conditions / Q000378:metabolism* / Q000473:pathology; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
D016159:Tumor Suppressor Protein p53; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human