PCMP-E29 Antibody
Description
Definition and Overview
The E29 antibody is a mouse monoclonal IgG2a isotype directed against MUC1, a transmembrane glycoprotein expressed on epithelial cells and overexpressed in numerous cancers (e.g., breast, ovarian, lung). It serves as a pan-epithelial marker for identifying neoplastic cells and distinguishing tumor types in histopathology .
Antibody Characteristics
Diagnostic Utility
E29 is used to:
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Identify epithelial origin: Detect metastatic carcinomas in bone marrow or liver .
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Exclude non-epithelial tumors: Hepatocellular carcinoma, adrenal carcinoma, and embryonal carcinomas are typically EMA-negative .
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Distinguish meningiomas: EMA positivity aids in differentiating meningiomas from other intracranial tumors .
Research Applications
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Tumor biology: Studies MUC1’s role in adhesion, anti-adhesion, and signaling (ERK, SRC, NF-κB pathways) .
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Therapeutic targeting: Investigates MUC1’s overexpression in cancers (e.g., breast, ovarian) and its potential as a therapeutic target .
E29 vs. HMFG-2 (Another Anti-MUC1 Antibody)
Source: Comparative IHC studies on 25 tissues (17 malignant, 8 benign) .
Mechanism and Functional Insights
MUC1 Structure and Function
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Alpha subunit: Mediates adhesion/anti-adhesion and forms a protective barrier against pathogens .
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Beta subunit: Involved in signaling via phosphorylation (e.g., ERK, SRC) and interacts with β-catenin .
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Post-translational modifications: Extensively O-glycosylated, with sialylation patterns varying by tissue type .
Clinical Implications
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Tumor progression: MUC1 overexpression correlates with metastasis and poor prognosis .
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Diagnostic markers: E29’s specificity helps exclude non-epithelial tumors (e.g., seminomas, hepatomas) .
Limitations and Considerations
Product Specs
Q&A
Basic Research Questions
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What is the E29 anti-EMA antibody and what epitopes does it recognize?
The E29 antibody is a mouse monoclonal antibody that recognizes Epithelial Membrane Antigen (EMA), also known as MUC1 (Mucin 1). It was developed using human milk fat globule membrane preparation as the immunogen . This antibody detects both normal and neoplastic epithelial cells from various tissues and serves as a useful marker for staining many carcinomas . The antibody recognizes specific epitopes on the protein backbone of MUC1, a large transmembrane glycoprotein expressed by most glandular and ductal epithelial cells .
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What are the primary applications of E29 antibody in experimental pathology?
The E29 antibody is primarily used in immunohistochemistry on formalin-fixed, paraffin-embedded tissue sections (IHC-P) . It serves as a pan-epithelial marker for categorizing cancers of epithelial origin and detecting metastatic loci . This antibody is particularly valuable in diagnostic histopathology for establishing the epithelial nature of neoplastic cells and produces membranous and cytoplasmic visualization patterns in positive cells . Some research protocols may also incorporate this antibody in western blot (WB) applications, though IHC remains its predominant use .
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Which tissue types typically show positive staining with the E29 antibody?
The E29 antibody stains both normal and neoplastic cells from various tissues, including:
Notably, hepatocellular carcinoma, adrenal carcinoma, and embryonal carcinomas are consistently EMA negative, making this antibody valuable in differential diagnoses .
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How does the E29 clone compare to other anti-EMA antibodies in research applications?
Studies comparing E29 with other anti-EMA antibodies, such as HMFG-2 (another monoclonal) and polyclonal antibodies, found similar staining distributions but important differences in quality and intensity . E29 gives a "cleaner" result than HMFG-2, with better discrimination between cells and stroma, making it highly suitable for routine diagnostic histopathology . Polyclonal antibodies produced stronger staining in colorectal carcinomas and lactating breast, whereas E29 showed stronger staining in non-neoplastic pleural mesothelium and pulmonary alveolar cells . When two monoclonals (E29 and HMFG-2) were mixed, there was no increase in staining intensity, suggesting that combining these antibodies offers no additional benefit .
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What is the recommended immunohistochemistry protocol for optimal E29 antibody staining?
For optimal IHC-P results with the E29 antibody:
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Dilution range: 1:100 to 1:500, though this may vary by supplier and specific application
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Pretreatment: Heat-induced epitope retrieval or enzymatic retrieval is recommended for deparaffinized tissue
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Control tissue: Breast carcinoma is commonly used as a positive control
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Visualization: Membranous and cytoplasmic staining patterns should be expected
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Storage: Store at 2-8°C; avoid repeated freeze-thaw cycles to maintain antibody integrity
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Incubation: Follow supplier-specific recommendations, typically 30 minutes at room temperature for prediluted formulations
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