Association between Cyclooxygenase expression and colorectal adenoma characteristics.
The cyclooxygenase (COX) pathway is important in colorectal carcinogenesis with the majority of cancers overexpressing COX-2; however, the role of COX-2 in the development of colorectal adenomas is less well defined. Accordingly, we analyzed 108 colorectal adenomas for COX-1 and COX-2 transcription in archival formalin-fixed, paraffin-embedded tissue using by real-time PCR and normalized to beta-actin. Neither COX-1 nor COX-2 mRNA expression differed with regard to age or gender of the subject. COX-2 mRNA expression was significantly higher in distal adenomas (2.2 +/- 1.9) compared with proximal (0.7 +/- 0.5) adenomas (P < 0.0001) and in larger (>/=7 mm) compared with smaller (<7 mm) adenomas (2.3 +/- 2.2 and 1.7 +/- 1.3, respectively, P = 0.04). COX-2 expression did not differ significantly in tubular compared with tubulovillous adenomas, although there appeared to be a trend toward higher COX-2 expression in tubulovillous adenomas with increasing villous content. Additionally, there was not a significant difference in either COX-1 or COX-2 based on the degree of dysplasia Therefore, if COX-2 inhibitors work through a COX-2 mechanism, these agents may have differential effects on colorectal adenomas that are distal and larger.
Einspahr
Janine G
JG
Arizona Cancer Center, University of Arizona, Tucson, Arizona 85724, USA. jeinspahr@azcc.arizona.edu
Krouse
Robert S
RS
Yochim
Ji Min
JM
Danenberg
Peter V
PV
Danenberg
Kathleen D
KD
Bhattacharyya
Achyut K
AK
Martínez
María E
ME
Alberts
David S
DS
D000236:Adenoma / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D005260:Female; D015870:Gene Expression; D006801:Humans; D007527:Isoenzymes / Q000096:biosynthesis* / Q000235:genetics; D008297:Male; D008565:Membrane Proteins; D008875:Middle Aged; D016612:Paraffin Embedding; D016133:Polymerase Chain Reaction; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics
D007527:Isoenzymes; D008565:Membrane Proteins; D012333:RNA, Messenger; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496511:PTGS1 protein, human; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases