Immunohistochemical expression of cyclooxygenase-2 in skin cancers.
BACKGROUND
Cyclooxygenase (COX), also known as prostaglandin endoperoxide synthase, catalyses the conversion of arachidonic acid to prostanoids. There are two different isoforms of COX, referred to as COX-1 and COX-2. Overexpression of COX-2 has been demonstrated in various neoplasms, such as experimentally promoted tumors, gastrointestinal cancers and breast tumors.


METHODS
In this study, we used immunohistochemistry to investigate COX-2 expression in a series of basal cell epitheliomas (BCE), Bowen's disease, squamous cell carcinomas (SCC) and metastatic tumors of the skin.


RESULTS
Four of 16 BCE showed a positive reaction for COX-2 and the adenoid type of BCE was the most strongly positive. In Bowen's disease, the extent of positive staining for COX-2 was even higher than that in BCE. Eleven of 15 SCC showed a positive reaction for COX-2 and the pattern of staining was heterogeneous with more intense staining in the center of the tumor nests. In metastatic tumors, the percentage of COX-2-positive tumor cells and the intensity of their staining was low compared with Bowen's disease and SCC.


CONCLUSIONS
These results indicate that the intensity of COX-2 staining and its heterogeneous distribution are related to the degree of cellular differentiation and the various phenotypes of tumor cells, but the extent of COX-2 staining did not correlate with the degree of malignancy.
Kagoura
M
M
Department of Dermatology, Faculty of Medicine, Toyama Medical and Pharmaceutical University, Toyama, Japan. kago@ms.toyama-mpu.ac.jp
Toyoda
M
M
Matsui
C
C
Morohashi
M
M
D000230:Adenocarcinoma / Q000737:chemistry / Q000201:enzymology* / Q000556:secondary; D001913:Bowen's Disease / Q000737:chemistry / Q000201:enzymology* / Q000473:pathology; D002280:Basal Cell Carcinoma / Q000737:chemistry / Q000201:enzymology* / Q000473:pathology; D002452:Cell Count; D051546:Cyclooxygenase 2; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000032:analysis / Q000378:metabolism*; D008565:Membrane Proteins; D010641:Phenotype; D011451:Prostaglandin-Endoperoxide Synthases / Q000032:analysis / Q000378:metabolism*; D012878:Skin Neoplasms / Q000737:chemistry / Q000201:enzymology* / Q000473:pathology
D007527:Isoenzymes; D008565:Membrane Proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases