Immunohistochemical analysis of Omi/HtrA2 expression in stomach cancer.
The serine protease Omi/HtrA2 is released from mitochondria into the cytosol after apoptosis stimuli, inducing apoptosis in a caspase-independent manner through its protease activity and in a caspase-dependent manner by neutralizing the inhibition of inhibitor of apoptosis proteins (IAPs) on caspases. Alteration of apoptosis is essential for cancer development, and cancer cell death by radiation and chemotherapy is largely dependent upon apoptosis. Thus, analysis of the expression status of Omi/HtrA2, a regulator of apoptosis, in cancer tissues is needed for an understanding of cancer development. In the current study, we analyzed the expression of Omi/HtrA2 in 60 advanced gastric adenocarcinomas by immunohistochemistry using a tissue microarray approach. Immunopositivity (defined as >/=30%) was observed for Omi/HtrA2 in 43 (72%) of the 60 cancers. By contrast, the surface mucous cells and mucous neck cells in the normal gastric mucosa showed no or weak expression of Omi/HtrA2. Taken together, these results suggest that stomach cancer cells in vivo may need Omi/HtrA2 expression for apoptosis, and that Omi/HtrA2 expression might be involved in stomach cancer development.
Lee
Sug Hyung
SH
Department of Pathology, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Lee
Jong Woo
JW
Kim
Hong Sug
HS
Kim
Su Young
SY
Park
Won Sang
WS
Kim
Sang Ho
SH
Lee
Jung Young
JY
Yoo
Nam Jin
NJ
D000230:Adenocarcinoma / Q000201:enzymology* / Q000473:pathology; D017209:Apoptosis; D005753:Gastric Mucosa / Q000201:enzymology / Q000473:pathology; D000074923:High-Temperature Requirement A Serine Peptidase 2; D006801:Humans; D007150:Immunohistochemistry; D024101:Mitochondrial Proteins; D012697:Serine Endopeptidases / Q000378:metabolism*; D013274:Stomach Neoplasms / Q000201:enzymology* / Q000473:pathology
D024101:Mitochondrial Proteins; D012697:Serine Endopeptidases; C000615914:HTRA2 protein, human; D000074923:High-Temperature Requirement A Serine Peptidase 2