BACKGROUND & AIMS: Multiple studies show that continuous use of nonsteroidal anti-inflammatory drugs (NSAIDs) lowers the risk of colon cancer in humans and carcinogen-treated rodents. One target for NSAIDs is cyclooxygenase (COX), and two isoforms of this enzyme have been identified: COX-1 and COX-2. The present study was undertaken to determine if there is differential expression of COX in colonic tumors in azoxymethane-treated rats. METHODS: COX-1 and COX-2 messenger RNA levels were determined by Northern blot analysis of total RNA isolated from colonic tumors and normal adjacent mucosa. COX-2 protein levels were determined by Western blotting analysis. Quantitation of relative band densities was performed using standard densitometry scanning techniques. RESULTS: There was a marked increase in COX-2 RNA levels in six of six colonic tumors compared with paired normal mucosa. In contrast, there was equivalent intensity of the COX-1 RNA transcript between the normal mucosa and tumor in all of the specimens examined. Western blotting analysis showed an increase in the level of the COX-2 protein in four of five of the colonic tumor samples. CONCLUSIONS: COX-2 but not COX-1 gene expression is markedly elevated in most colonic tumors examined in azoxymethane-treated rodents. COX-2 may provide a target for chemopreventive strategies for colorectal cancer.
BACKGROUND & AIMS: Multiple studies show that continuous use of nonsteroidal anti-inflammatory drugs (NSAIDs) lowers the risk of colon cancer in humans and carcinogen-treated rodents. One target for NSAIDs is cyclooxygenase (COX), and two isoforms of this enzyme have been identified: COX-1 and COX-2. The present study was undertaken to determine if there is differential expression of COX in colonic tumors in azoxymethane-treated rats. METHODS:COX-1 and COX-2 messenger RNA levels were determined by Northern blot analysis of total RNA isolated from colonic tumors and normal adjacent mucosa. COX-2 protein levels were determined by Western blotting analysis. Quantitation of relative band densities was performed using standard densitometry scanning techniques. RESULTS: There was a marked increase in COX-2 RNA levels in six of six colonic tumors compared with paired normal mucosa. In contrast, there was equivalent intensity of the COX-1 RNA transcript between the normal mucosa and tumor in all of the specimens examined. Western blotting analysis showed an increase in the level of the COX-2 protein in four of five of the colonic tumor samples. CONCLUSIONS:COX-2 but not COX-1 gene expression is markedly elevated in most colonic tumors examined in azoxymethane-treated rodents. COX-2 may provide a target for chemopreventive strategies for colorectal cancer.
Authors: R J Coffey; C J Hawkey; L Damstrup; R Graves-Deal; V C Daniel; P J Dempsey; R Chinery; S C Kirkland; R N DuBois; T L Jetton; J D Morrow Journal: Proc Natl Acad Sci U S A Date: 1997-01-21 Impact factor: 11.205
Authors: Takumu Hasebe; Jun Matsukawa; Daina Ringus; Jun Miyoshi; John Hart; Atsushi Kaneko; Masahiro Yamamoto; Toru Kono; Mikihiro Fujiya; Yutaka Kohgo; Chong-Zi Wang; Chun-Su Yuan; Marc Bissonnette; Mark W Musch; Eugene B Chang Journal: Phytother Res Date: 2016-10-12 Impact factor: 5.878
Authors: Scott C Borinstein; Melissa Conerly; Slavomir Dzieciatkowski; Swati Biswas; M Kay Washington; Patty Trobridge; Steve Henikoff; William M Grady Journal: Mol Carcinog Date: 2010-01 Impact factor: 4.784
Authors: A Strillacci; C Griffoni; G Lazzarini; M C Valerii; S Di Molfetta; F Rizzello; M Campieri; M P Moyer; V Tomasi; E Spisni Journal: Br J Cancer Date: 2010-08-17 Impact factor: 7.640