
-   PTGS1 gene expression were significant positive predictor of colon prostaglandin E2 (PGE2) concentrations after controlling for nonsteroidal anti-inflammatory drug use, gender, age, and smoking status. PGE2 in the colon is a pro-inflammatory mediator that is associated with increased risk of colon cancer [PMID: 27548026].
-   In the rat, the COX-1 gene expresses an alternatively spliced mRNA COX-1 splice variant (SV). COX-1SV mRNA levels were elevated in colorectal tumours and reduced after NSAID treatment to the levels observed in normal colonic mucosa [PMID: 11375891].
-   Azoxymethane (AOM) is a potent DNA-damaging agent and carcinogen that induces intestinal and colonic tumors in rodents. COX-1 mRNA and protein expression as well as COX-1-derived PGE(2) synthesis were increased 8 h after AOM treatment in mice [PMID: 17038629].
-   Colocalization of COX-1, COX-2 and mPGES was found in the intestinal polyp stromal fibroblasts of Apc(Delta 716) mice, a model for familial adenomatous polyposis. Contrary to COX-2 that was induced only in polyps >1 mm in diameter, COX-1 was found in polyps of any size. Although polyp number and size were markedly reduced in COX-1 (-/-) or COX-2 (-/-) compound mutant Apc mice, both COX-2 and mPGES were induced in the COX-1 (-/-) polyps, whereas COX-1 was expressed in the COX-2 (-/-) polyps, indicating a cooperation of COX-1 and COX-2 in intestinal polyposis [PMID: 12941808].
