Activation of beta-adrenoceptors and the subsequent stimulation of COX-2, PGE(2), and VEGF expression is perhaps an important mechanism in the tumorigenic action of nicotine on colon tumor growth.
Although the cyclooxygenase-2 (COX-2) pathway of the arachidonic acid cascade has been suggested to play an important role in colon carcinogenesis, there is little information concerning the identity of phospholipase A(2) (PLA(2)) involved in the arachidonic acid release in colon tumors.
Collectively, our data indicate that COX-2 promotes colon tumor progression, but not initiation, and it does so, in part, by activating EGFR and Akt signaling pathways.
Combination of 5-fluorouracil and genistein induces apoptosis synergistically in chemo-resistant cancer cells through the modulation of AMPK and COX-2 signaling pathways.
Cyclooxygenase catalyses a key step in prostaglandin biosynthesis, and recent work suggests that one isoenzyme, COX-2, has important roles in early stages of pregnancy; it also appears to be involved in the somewhat analogous process of colon tumor formation and spread.
Herein, we demonstrate that 15-PGDH is active in vivo as a highly potent suppressor of colon neoplasia development and acts in the colon as a required physiologic antagonist of the prostaglandin-synthesizing activity of the cyclooxygenase 2 (COX-2) oncogene.
In Apc(Min) (/+) mice, constitutive CpG methylation of the Fxrα3/4 promoter was linked to reduced (60-90%) baseline Fxr, Ibabp, and Shp and increased Cox-2 expression in apparently normal adjacent mucosa and colon tumors.
Marked increased expression of cyclooxygenase 2 (COX-2), a prostaglandin-synthesizing enzyme that is pharmacologically inhibited by nonsteroid anti-inflammatory-type drugs, is a major early oncogenic event in the genesis of human colon neoplasia.
Marked increased expression of cyclooxygenase 2 (COX-2), a prostaglandin-synthesizing enzyme that is pharmacologically inhibited by nonsteroid anti-inflammatory-type drugs, is a major early oncogenic event in the genesis of human colon neoplasia.
Moreover, CCL2 antagonists decreased intracolonic macrophage infiltration and COX-2 expression, attenuated neovascularization, and eventually reduced the numbers and size of colon tumors, even when given after multiple colon tumors have developed.
No linkage between COX2 and colon neoplasia was found by use of a multipoint model-free linkage analysis (estimate of allele sharing was 0.44; standard error = +/-0.04; 95% confidence interval = 0.36 to 0.52).