title: Immunohistochemical analysis of Omi/HtrA2 expression in stomach cancer.
abstract: 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.
authors.affiliation: Department of Pathology, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Sug Hyung
authors.initials: SH
authors.lastname: Lee
authors.forename: Jong Woo
authors.initials: JW
authors.lastname: Lee
authors.forename: Hong Sug
authors.initials: HS
authors.lastname: Kim
authors.forename: Su Young
authors.initials: SY
authors.lastname: Kim
authors.forename: Won Sang
authors.initials: WS
authors.lastname: Park
authors.forename: Sang Ho
authors.initials: SH
authors.lastname: Kim
authors.forename: Jung Young
authors.initials: JY
authors.lastname: Lee
authors.forename: Nam Jin
authors.initials: NJ
authors.lastname: Yoo
mesh_terms: 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
chemical_list: D024101:Mitochondrial Proteins; D012697:Serine Endopeptidases; C000615914:HTRA2 protein, human; D000074923:High-Temperature Requirement A Serine Peptidase 2