Nuclear factor kappaB (NFkappaB) and cyclooxygenase-2 (Cox-2) expression in the irradiated colorectum is associated with subsequent histopathological changes.
OBJECTIVE
Recent studies have proposed that mucositis development is the same throughout the gastrointestinal tract (GIT), as it is formed from one structure embryologically. Radiation-induced oral mucositis studies have outlined the key involvement of nuclear factor kappaB (NFkappaB) and cyclooxygenase-2 (Cox-2) in its pathobiology. The purpose of this study was therefore to investigate the expression of NFkappaB and Cox-2 in the irradiated colorectum and to correlate these with the associated histopathologic changes.


METHODS
Colorectal tissues from 28 colorectal cancer patients treated with preoperative radiotherapy were analyzed for histopathologic changes using a variety of tissue staining methods. The expression of NFkappaB and Cox-2 in these tissues was investigated using immunohistochemistry. Changes in expression of these proteins were then correlated with the histopathologic changes.


RESULTS
Radiation therapy caused injury to the normal colorectal tissue surrounding tumor site, particularly around the blood vessels. These changes were reflected in changes in NFkappaB and Cox-2 expression.


CONCLUSIONS
We conclude that different regions of the GIT, the colorectum, and oral cavity have similar underlying mechanisms of radiation-induced mucositis. Understanding these mechanisms will allow new approaches to be developed to specifically target steps in the evolution of alimentary mucositis.
Yeoh
Ann S J
AS
Department of Medical Oncology, Royal Adelaide Hospital, Adelaide, South Australia, Australia. ann.yeoh@imvs.sa.gov.au
Bowen
Joanne M
JM
Gibson
Rachel J
RJ
Keefe
Dorothy M K
DM
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003106:Colon / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects*; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D005260:Female; D020397:Goblet Cells / Q000473:pathology / Q000528:radiation effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D052016:Mucositis / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D016328:NF-kappa B / Q000378:metabolism*; D011832:Radiation Injuries / Q000378:metabolism* / Q000473:pathology; D012004:Rectal Neoplasms / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy; D012007:Rectum / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects*
D016328:NF-kappa B; D051546:Cyclooxygenase 2