title: Cyclooxygenase-2 plays a suppressive role for induction of apoptosis in isoliquiritigenin-treated mouse colon cancer cells.
abstract: Cellular damage induced by chronic inflammation is a well known cause of colon carcinogenesis. Cyclooxygenase-2 (COX-2), the enzyme that converts arachidonic acid to prostanoids, is known to play an important role in inflammation. Herbal flavonoid isoliquiritigenin (ILTG) has previously been reported to be a strong suppresser of the COX-2 pathway as well as an inducer of apoptosis. Here we report that the susceptibility to apoptosis by ILTG is dependent on the level of COX-2 in mouse colon adenocarcinoma Colon 26, which spontaneously expresses COX-2. This dependency was observed to be enhanced by blockage of the lipoxigenases (LOXs)-mediated metabolic pathway and attenuated by addition of a number of prostaglandins and thromboxanes. Taken together, these findings indicate that ILTG-induced apoptosis is negatively regulated by the COX-2 expression level.
authors.affiliation: Department of Natural Medicine and Phytochemistry, Meiji Pharmaceutical University, 2-522-1, Noshio, Kiyose-shi, Tokyo 204-8588, Japan.
authors.forename: Tetsuyuki
authors.initials: T
authors.lastname: Takahashi
authors.forename: Masaki
authors.initials: M
authors.lastname: Baba
authors.forename: Hoyoku
authors.initials: H
authors.lastname: Nishino
authors.forename: Toru
authors.initials: T
authors.lastname: Okuyama
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002599:Chalcone / Q000031:analogs & derivatives* / Q000627:therapeutic use; D047188:Chalcones; D003110:Colonic Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D051546:Cyclooxygenase 2 / Q000502:physiology*; D052246:Cyclooxygenase 2 Inhibitors / Q000627:therapeutic use*; D051379:Mice; D010944:Plants / Q000737:chemistry; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D011453:Prostaglandins / Q000378:metabolism; D013931:Thromboxanes / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D047188:Chalcones; D052246:Cyclooxygenase 2 Inhibitors; D011453:Prostaglandins; D013931:Thromboxanes; D002599:Chalcone; C040920:isoliquiritigenin; D051546:Cyclooxygenase 2; D011065:Poly(ADP-ribose) Polymerases; C505409:Casp3 protein, mouse; D053148:Caspase 3; D020169:Caspases