Decreased expression of 15-hydroxyprostaglandin dehydrogenase in gastric carcinomas.
OBJECTIVE
Gastric carcinoma tissues release high level of prostaglandin E2 (PGE2) when compared to non-neoplastic mucosa, and cyclooxygenase-2 (COX-2), which is the rate-limiting enzyme in prostaglandin (PG) biosynthesis, is often overexpressed in gastric carcinomas and during gastric carcinogenesis. However, little is known about the expression of 15-hydroxyprostaglandin dehydrogenase (15-PGDH), the key enzyme responsible for the biological inactivation of PG, in gastric carcinomas.


METHODS
We investigated the expression of 15-PGDH in 28 cases of advanced gastric carcinomas by Western blot analysis and also the relation between its expression and the gene promoter methylation.


RESULTS
15-PGDH expression was significantly decreased in gastric carcinomas compared to corresponding non-neoplastic tissues and inversely correlated with the expression of proliferating cell nuclear antigen in gastric carcinomas. However, there was no correlation between 15-PGDH expression and pathological findings such as nodal metastasis and vascular invasion. Promoter hypermethylation of 15-PGDH gene was not detected in carcinomas, with only a negligible expression of the enzyme.


CONCLUSIONS
Our results suggested that 15-PGDH has tumor suppressor activity in gastric carcinomas.
Jang
Tae Jung
TJ
Department of Pathology, Dongguk University College of Medicine, 707 Sukjang-dong, Kyongju, Kyongbuk 780-714, Korea. taejung@mail.dongguk.ac.kr
Ji
Ye Seob
YS
Jung
Ki Hoon
KH
D000368:Aged; D001483:Base Sequence; D019175:DNA Methylation; D017931:DNA Primers / Q000235:genetics; D004273:DNA, Neoplasm / Q000235:genetics; D005260:Female; D006801:Humans; D006911:Hydroxyprostaglandin Dehydrogenases / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011401:Promoter Regions, Genetic; D013274:Stomach Neoplasms / Q000201:enzymology* / Q000235:genetics
D017931:DNA Primers; D004273:DNA, Neoplasm; D006911:Hydroxyprostaglandin Dehydrogenases; C035859:15-hydroxyprostaglandin dehydrogenase