Overexpression of a novel superoxide-producing enzyme, NADPH oxidase 1, in adenoma and well differentiated adenocarcinoma of the human colon.
A superoxide-producing enzyme, NADPH oxidase 1 (Nox1), dominantly expressed in the colon, is implicated in the pathogenesis of colon cancer. Immunohistochemistry showed that Nox1 was constitutively expressed in surface mucous cells. Adenomas and well differentiated adenocarcinomas up-regulated Nox1 expression. Ki-67-negative, well differentiated tumor cells contained abundant Nox1, whereas Ki-67-positive, proliferating cells did not express it. This differentiation-dependent expression in normal as well as tumor tissues suggests distinct roles of Nox1 besides mitogenic function. Nuclear factor (NF)-kappaB was predominantly activated in adenoma and adenocarcinoma cells expressing abundant Nox1, suggesting that Nox1 may stimulate NF-kappaB-dependent antiapoptotic pathways in colon tumors.
Fukuyama
Mitsutoshi
M
Department of Digestive and Pediatric Surgery, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima City, Tokushima 770-8503, Japan.
Rokutan
Kazuhito
K
Sano
Toshiaki
T
Miyake
Hidenori
H
Shimada
Mitsuo
M
Tashiro
Seiki
S
D000230:Adenocarcinoma / Q000201:enzymology*; D000236:Adenoma / Q000201:enzymology*; D000328:Adult; D000368:Aged; D002454:Cell Differentiation; D003110:Colonic Neoplasms / Q000201:enzymology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000074624:NADPH Oxidase 1; D019255:NADPH Oxidases / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism; D015854:Up-Regulation
D016328:NF-kappa B; D000074624:NADPH Oxidase 1; D019255:NADPH Oxidases; C402799:NOX1 protein, human