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Updated: Aug 8, 2026
Heterogeneity Mapping of Protein Expression in Tumors using Quantitative Immunofluorescence
Published on: October 25, 2011
Immunohistochemical analysis of Omi/HtrA2 expression in stomach cancer
Sug Hyung Lee1, Jong Woo Lee, Hong Sug Kim
1Department of Pathology, College of Medicine, The Catholic University of Korea, Seoul, Korea.
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.
Insights
The serine protease Omi/HtrA2, a key apoptosis regulator, is highly expressed in most stomach cancers but not normal cells. This suggests Omi/HtrA2 plays a role in stomach cancer development and apoptosis.
Area of Science:
- Cell Biology
- Molecular Oncology
- Cancer Research
Background:
- The serine protease Omi/HtrA2 regulates apoptosis through caspase-dependent and -independent pathways.
- Apoptosis alterations are critical in cancer development, and cancer cell death relies on apoptosis.
- Understanding Omi/HtrA2 expression in cancer is vital for comprehending cancer development.
Purpose of the Study:
- To investigate the expression status of Omi/HtrA2 in advanced gastric adenocarcinomas.
- To correlate Omi/HtrA2 expression with stomach cancer development.
Main Methods:
- Immunohistochemistry was used to analyze Omi/HtrA2 expression.
- A tissue microarray approach was employed on 60 advanced gastric adenocarcinoma samples.
- Omi/HtrA2 immunopositivity was defined as >=30% staining.
Main Results:
- Omi/HtrA2 immunopositivity was observed in 72% (43/60) of advanced gastric adenocarcinomas.
- Normal gastric mucosa exhibited no or weak Omi/HtrA2 expression in surface mucous and mucous neck cells.
- A significant difference in Omi/HtrA2 expression was noted between cancer tissues and normal gastric mucosa.
Conclusions:
- Stomach cancer cells may require Omi/HtrA2 expression for apoptosis.
- Omi/HtrA2 expression is potentially involved in the development of stomach cancer.
- Omi/HtrA2 could serve as a biomarker or therapeutic target in gastric adenocarcinoma.
