Cyclooxygenase-2 expression is related to prostaglandin biosynthesis and angiogenesis in human gastric cancer.
Although recent studies have demonstrated that cyclooxygenase (COX)-2 is overexpressed in various cancers including gastric cancer, the mechanisms underlying the contribution of COX-2 to tumorigenesis and tumor promotion still remain unclear. To determine the role of COX-2, we investigated the COX-2 expression, the prostaglandin (PG) levels, and the microvessel density in 42 patients with primary gastric adenocarcinoma. COX-2 protein was over-expressed in 31 (74%) of 42 gastric cancers based on an immunoblot analysis. The intensity of COX-2 expression was found to significantly correlate with lymph node involvement. The COX-2 overexpressed cases showed significantly elevated levels of prostaglandin E2 (PGE2) in cancer tissues in comparison with the normal gastric mucosa by an immunoassay (201 +/- 90 versus 161 +/- 57 ng/mg protein; P < 0.05). However, the COX-2 overexpression was not related to the levels of thromboxane B2 and 6-keto-prostaglandin F1alpha. The density of microvessel immunostained with CD34 was significantly higher in patients demonstrating COX-2 overexpression than in those without such expression (63 +/-21 versus 45 +/- 17/200 x; P < 0.01). Our data thus suggested COX-2 overexpression to be associated with increased PGE2 biosynthesis and angiogenesis in gastric cancer, which indicates that COX-2 may play a role in the development of gastric cancer.
Uefuji
K
K
Department of Surgery I, National Defense Medical College, Tokorozawa, Japan. uefuji@dd.mbn.or.jp
Ichikura
T
T
Mochizuki
H
H
D000230:Adenocarcinoma / Q000098:blood supply* / Q000201:enzymology / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis; D051546:Cyclooxygenase 2; D015232:Dinoprostone / Q000096:biosynthesis*; D006801:Humans; D007527:Isoenzymes / Q000032:analysis / Q000378:metabolism*; D008207:Lymphatic Metastasis; D008565:Membrane Proteins; D008833:Microcirculation / Q000473:pathology; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D009389:Neovascularization, Pathologic; D011451:Prostaglandin-Endoperoxide Synthases / Q000032:analysis / Q000378:metabolism*; D013274:Stomach Neoplasms / Q000098:blood supply* / Q000201:enzymology / Q000473:pathology*
D014408:Biomarkers, Tumor; D007527:Isoenzymes; D008565:Membrane Proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D015232:Dinoprostone