BACKGROUND _ AIMS: Cyclooxygenase (COX) enzymes catalyze the conversion of @entity1426 to @entity2918 . Evidence suggests that nonsteroidal anti-inflammatory drugs reduce the risk of @entity14 ( @entity14 ) and that this effect is mediated through COX inhibition. We analyzed and compared expression of the inducible @entity2247 isoform in @entity14 from @entity1 with @entity14 ( @entity14 ), @entity1412 ( @entity1412 ), and sporadic @entity14 . Given that @entity2247 is induced by transforming growth factor (TGF)-beta and that @entity2534 (RII) mutations are found in HNPCCs, we determined the relationship between RII status and @entity2247 expression. METHODS: @entity2247 protein expression was determined in colorectal epithelia using immunohistochemistry and Western blotting. @entity1 with @entity14 had known mutations in @entity6756 or @entity4311 genes and/or met the Amsterdam criteria. In CRCs from @entity14 cases, mutations were sought in the coding region of the RII gene using the polymerase chain reaction. RESULTS: @entity2247 was detected in @entity652 from 2 of 3 @entity14 , 6 of 7 @entity1412 , and 5 of 8 sporadic cases. In CRCs, @entity2247 staining was found in 16 of 24 (67%) @entity14 vs. 24 of 26 (92%) sporadic cases (P = 0.035) and in 2 of 2 @entity1412 cases. Staining intensity was reduced in HNPCCs compared with sporadic CRCs (P = 0.035). Staining localized to the cytoplasm of neoplastic cells; normal epithelial cells were negative for @entity2247 . Overexpression of @entity2247 in CRCs relative to normal mucosa was confirmed by Western blotting. TGF-beta RII mutations were detected in 12 of 14 HNPCCs examined, including 3 of 4 @entity2247 -negative and 9 of 10 @entity2247 -positive @entity5 . CONCLUSIONS: The frequency and intensity of @entity2247 expression was significantly reduced in HNPCCs relative to sporadic CRCs, and was not a consequence of RII mutations. Given that many HNPCCs express @entity2247 , inhibition of this enzyme may be an important strategy to prevent @entity14 in these @entity1 .

Reduced expression of cyclooxygenase 2 proteins in XXXX .

@entity1 :: ('9606', 'Species') :: ['Patients', 'patients'] @entity6756 :: ('4292', 'Gene') :: ['hMLH1'] @entity652 :: ('MESH:D000236', 'Disease') :: ['adenomas'] @entity2534 :: ('7048', 'Gene') :: ['TGF-beta type II receptor'] @entity5 :: ('MESH:D009369', 'Disease') :: ['cancers'] @entity2918 :: ('MESH:D011453', 'Chemical') :: ['prostaglandins'] @entity1426 :: ('MESH:D016718', 'Chemical') :: ['arachidonic acid'] @entity4311 :: ('4436', 'Gene') :: ['hMSH2'] @entity14 :: ('MESH:D015179', 'Disease') :: ['hereditary nonpolyposis colorectal cancer', 'HNPCC', 'CRC', 'colorectal neoplasms', 'colorectal cancer'] @entity2247 :: ('4513', 'Gene') :: ['COX-2'] @entity1412 :: ('MESH:D011125', 'Disease') :: ['familial adenomatous polyposis', 'FAP']
@entity5 :: (MESH:D009369,Disease) :: ['hereditary nonpolyposis colorectal cancers relative to sporadic cancers']
