%0 Journal Article %A J Dimberg %A A Samuelsson %A A Hugander %A P Söderkvist %T Differential expression of cyclooxygenase 2 in human colorectal cancer %D 1999 %R 10.1136/gut.45.5.730 %J Gut %P 730-732 %V 45 %N 5 %X BACKGROUND Experimental, clinical, and epidemiological studies have implicated mitogenic metabolites of arachidonic acid such as prostaglandin E2(PGE2) in colorectal carcinogenesis. Recently, cyclooxygenase 2 (COX-2) which catalyses the conversion of arachidonic acid to PGE2, has displayed increased levels in human colorectal cancer.AIMS To evaluate whether there is differential COX-2 expression from different locations (caecum, ascending, transverse, descending, or sigmoid colon, and rectum) in human colorectal cancer.METHODS Protein levels of COX-2 were determined by western blot analysis in tumours and adjacent normal mucosa of 39 patients with colorectal cancer.RESULTS There was a notable overexpression of COX-2 protein in tumours located in the rectum (p<0.001) compared with other locations in the colon. Rectal tumours revealed elevated COX-2 protein levels in 18/20 cases compared with 4/19 colonic cases. No association between enhanced COX-2 protein expression in tumour tissue and Dukes’s stages was found.CONCLUSIONS Results suggest that the differential COX-2 expression may be due to differences in gene regulatory factors affecting COX-2 expression and/or reflect secondary changes in tumour progression which may have clinical implications.APCadenomatous polyposis coliCOXcyclooxygenasecPLA2cytosolic phospholipase A2NSAIDnon-steroidal anti-inflammatory drugPGE2prostaglandin E2PLA2-IIgroup II phospholipase A2PPARγperoxisome proliferator activated receptorTCF/LEFT cell factor/leucocyte enhancing factor %U https://gut.bmj.com/content/gutjnl/45/5/730.full.pdf