Expression of phosphorylated caspase-9 in gastric carcinomas.
Alterations of caspases, the main executioners of apoptosis, have been described in human cancers. Caspase-9 plays a crucial role in the initiation phase of the intrinsic apoptosis pathway. Caspase-9 is phosphorylated at Thr125 through the mitogen-activated protein kinase (MAPK) pathway, and this phosphorylation is associated with inhibition of caspase-9 activation. The aim of this study was to explore whether phosphorylated caspase-9 (p-caspase-9) expression could be a characteristic of gastric carcinomas. We analyzed expression of p-caspase-9 protein in 60 gastric adenocarcinomas by immunohistochemistry using a tissue microarray approach. p-caspase-9 was detected in 33 of the 60 carcinomas (55%). Both early and advanced gastric carcinomas expressed p-caspase-9. There was no significant association of p-caspase-9 expression with clinocopathological characteristics, including invasion, metastasis and stage. In contrast to gastric cancer cells, epithelial cells in normal gastric mucosa showed no or only weak expression of p-caspase-9. Taken together, these results indicate that caspase-9 is frequently phosphorylated in gastric carcinomas, and that the phosphorylation of caspase-9 might be an inhibitory mechanism of caspase-9-mediated apoptosis in gastric carcinomas. Increased expression of p-caspase-9 in malignant gastric epithelial cells compared to normal mucosal epithelial cells suggests that p-caspase-9 expression might play a role in gastric carcinoma development.
Yoo
Nam Jin
NJ
Department of Pathology, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Lee
Sung Hak
SH
Jeong
Eun Goo
EG
Lee
Sug Hyung
SH
D002277:Carcinoma / Q000201:enzymology*; D053453:Caspase 9 / Q000032:analysis* / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D010766:Phosphorylation; D013274:Stomach Neoplasms / Q000201:enzymology*; D046888:Tissue Array Analysis
D053453:Caspase 9