Expression of TGF-beta and procollagen type I and type III in human gastric carcinomas.
To elucidate the difference between scirrhous and non-scirrhous gastric carcinomas, we examined the expressions of TGF-beta, procollagen type I and type III in 7 gastric carcinoma cell lines and 37 gastric carcinoma tissues, and also examined the effect of TGF-beta on the expression of procollagen mRNA by TMK-I cells. TGF-beta mRNA was detected in all the tumors examined in vivo and in vitro. Interestingly, 9 (90%) of 10 scirrhous gastric carcinomas revealed higher levels of TGF-beta mRNA than normal tissues, while 8 (38%) of 21 well-differentiated adenocarcinomas had higher TGF-beta mRNA levels than normal tissues. As for procollagen mRNA, most of the human gastric carcinoma cell lines expressed type-I procollagen mRNA and MKN-I expressed type-III procollagen mRNA. Furthermore, procollagen type-I mRNA accumulation in TMK-I cells was increased by exogenous TGF-beta. Most of the tumor tissues from surgical specimens expressed higher procollagen mRNA than normal tissues. These results indicate that TGF-beta produced by carcinoma cells might stimulate collagen synthesis not only by fibroblasts but also by carcinoma cells themselves, leading to diffuse fibrosis of scirrhous gastric carcinomas.
Yoshida
K
K
First Department of Pathology, Hiroshima University School of Medicine, Japan.
Yokozaki
H
H
Niimoto
M
M
Ito
H
H
Ito
M
M
Tahara
E
E
D002277:Carcinoma / Q000378:metabolism*; D006801:Humans; D011347:Procollagen / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis*; D013274:Stomach Neoplasms / Q000378:metabolism*; D015291:Transforming Growth Factors / Q000235:genetics* / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D011347:Procollagen; D012333:RNA, Messenger; D015291:Transforming Growth Factors