Potential role of group X secretory phospholipase A(2) in cyclooxygenase-2-dependent PGE(2) formation during colon tumorigenesis.
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. Here, we compared the potencies of three types of secretory PLA(2)s (group IB, IIA and X sPLA(2)s) for the arachidonic acid release from cultured human colon adenocarcinoma cells, and found that group X sPLA(2) has the most powerful potency in the release of arachidonic acid leading to COX-2-dependent prostaglandin E(2) (PGE(2)) formation. Furthermore, immunohistological analysis revealed the elevated expression of group X sPLA(2) in human colon adenocarcinoma neoplastic cells in concert with augmented expression of COX-2. These findings suggest a critical role of group X sPLA(2) in the PGE(2) biosynthesis during colon tumorigenesis.
Morioka
Y
Y
Shionogi Research Laboratories, Shionogi and Co., Ltd., Sagisu 5-12-4, Fukushima-ku, 553-0002, Osaka, Japan.
Ikeda
M
M
Saiga
A
A
Fujii
N
N
Ishimoto
Y
Y
Arita
H
H
Hanasaki
K
K
D000230:Adenocarcinoma / Q000201:enzymology* / Q000473:pathology / Q000503:physiopathology; D003106:Colon / Q000201:enzymology / Q000473:pathology; D003110:Colonic Neoplasms / Q000201:enzymology* / Q000473:pathology / Q000503:physiopathology; D015179:Colorectal Neoplasms / Q000201:enzymology / Q000473:pathology; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D015232:Dinoprostone / Q000378:metabolism*; D054501:Group II Phospholipases A2; D006801:Humans; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins; D010741:Phospholipases A / Q000378:metabolism*; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D014407:Tumor Cells, Cultured
D007527:Isoenzymes; D008565:Membrane Proteins; D011994:Recombinant Proteins; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496511:PTGS1 protein, human; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D010741:Phospholipases A; D054501:Group II Phospholipases A2; D015232:Dinoprostone