Cyclooxygenase-2 expression is related to prostaglandin biosynthesis and angiogenesis in human gastric cancer

K Uefuji, T Ichikura, H Mochizuki - Clinical cancer research, 2000 - AACR
K Uefuji, T Ichikura, H Mochizuki
Clinical cancer research, 2000AACR
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
overexpressed in 31 (74%) of 42 gastric cancers based on an immunoblot analysis. The …
Abstract
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 overexpressed 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 F. 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 ×; P < 0.01). Our data thus suggested COX-2 overexpression to be associated with increased PGE2biosynthesis and angiogenesis in gastric cancer, which indicates that COX-2 may play a role in the development of gastric cancer.
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