Collagen biosynthesis in gastric cancer: immunohistochemical analysis of prolyl 4-hydroxylase.
OBJECTIVE
The mechanism of the desmoplastic response in gastric carcinoma tissues is largely unknown. The objective of this study is to determine the localization of prolyl 4-hydroxylase (PH), an enzyme that plays a crucial role in collagen biosynthesis.


METHODS
Freshly prepared gastric carcinoma tissues from 51 cases, including 13 of the scirrhous type (diffusely infiltrative type), were immunostained by using monoclonal antibodies to human placental PH.


RESULTS
Although cytoplasmic staining for PH was observed in both fibroblasts and carcinoma cells, there was increased expression of the alpha-subunit in fibroblasts and no difference in expression between the scirrhous and non-scirrhous type gastric carcinomas. In scirrhous type samples, there was increased PH expression in fibroblasts located in the tumor periphery when compared with fibroblasts in the tumor center. These findings suggested that maintenance of a balance between production and degradation of collagen in gastric carcinoma tissues might be important for stroma formation.


CONCLUSIONS
It is speculated that activated fibroblasts participate in collagen biosynthesis at the tumor periphery rather than in the tumor center and that increased collagen biosynthesis at the tumor periphery in scirrhous gastric carcinoma may assist further invasion of tumor cells.
Matsui
H
H
Department of Surgery, School of Medicine, Keio University, Tokyo, Japan. hmatsui@fujita-hu.ac.jp
Kubochi
K
K
Okazaki
I
I
Yoshino
K
K
Ishibiki
K
K
Kitajima
M
M
D002293:Adenocarcinoma, Scirrhous / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D002450:Cell Communication; D003094:Collagen / Q000096:biosynthesis*; D006801:Humans; D007150:Immunohistochemistry; D011393:Procollagen-Proline Dioxygenase / Q000378:metabolism*; D013274:Stomach Neoplasms / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D014407:Tumor Cells, Cultured
D003094:Collagen; D011393:Procollagen-Proline Dioxygenase