CHGA Antibody
Description
Structure and Function of CHGA Antibodies
CHGA antibodies are designed to bind specifically to chromogranin A, a 80 kDa protein stored in dense-core secretory vesicles of neurons and endocrine cells . These antibodies facilitate the study of CHGA’s roles, including:
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Osmotic regulation within secretory vesicles, enabling monoamine storage .
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Precursor to bioactive peptides such as vasostatin, pancreastatin, and catestatin .
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Biomarker for neuroendocrine tumors (e.g., carcinoid tumors, pheochromocytomas) .
Key Antibody Characteristics
| Antibody Clone/Source | Isotype | Species Reactivity | Applications |
|---|---|---|---|
| CHGA Antibody #60893 (CST) | Rabbit | Human | WB, IP |
| CHGA/798 (ThermoFisher) | Mouse Monoclonal | Human, Mouse, Rat | IHC-P, WB |
| CPTC-CHGA-1 (DSHB) | Mouse IgG2b | Human | ELISA, WB |
| CHGA/798 (Abcam) | Mouse Monoclonal | Human, Mouse, Rat | IHC-P |
WB = Western Blotting; IP = Immunoprecipitation; IHC-P = Immunohistochemistry (Paraffin-embedded) .
Neuroendocrine Tumor Detection
CHGA antibodies are pivotal in identifying neuroendocrine tumors (NETs), which often express CHGA. For example:
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Immunohistochemistry (IHC): CHGA/798 (ThermoFisher) and ab220191 (Abcam) are validated for staining NETs in formalin-fixed tissues, requiring antigen retrieval (e.g., Tris-EDTA buffer, pH 9.0, 95°C for 45 minutes) .
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Serological Markers: Elevated CHGA levels in blood or urine correlate with NET progression and therapeutic response .
Biomarker for Colon Cancer
Recent studies highlight CHGA’s potential as an early diagnostic marker for colon cancer:
| Biomarker | Sensitivity | Specificity | DOR |
|---|---|---|---|
| CHGA | 0.89 | 0.89 | 57.27 |
| MKI67 | 0.86 | 0.81 | 27.65 |
| TP53 | 0.78 | 0.54 | 2.36 |
| KRAS | 0.82 | 0.77 | 9.78 |
| DOR = Diagnostic Odds Ratio; higher values indicate superior diagnostic performance . |
Mechanistic Insights
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Haplotype Variants: The CHGA promoter haplotype 2 (−1018T, −415T, −57T) enhances transcriptional activity, potentially linking CHGA expression to metabolic/cardiovascular risks .
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Reporter Systems: A ChgA-hrGFP reporter system revealed CHGA expression in enteroendocrine cells (e.g., serotonin/histamine-storing EC cells) and pancreatic islet cells, aiding studies on monoamine storage .
Antibody Performance
| Antibody | ELISA | WB | IHC |
|---|---|---|---|
| CPTC-CHGA-1 | Positive | Positive | Negative |
| CPTC-CHGA-2 | Positive | Positive | Negative |
| CHGA/798 | N/A | Positive | Positive |
| Negative results indicate unsuitability for the listed application . |
Limitations
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Species Cross-Reactivity: Rabbit CHGA antibodies (e.g., #60893) show limited cross-reactivity, whereas mouse monoclonal clones (e.g., CHGA/798) target human, mouse, and rat CHGA .
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Assay Optimization: IHC requires rigorous antigen retrieval due to CHGA’s acidic nature and formalin fixation .
Neuroendocrine Tumor Management
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Disease Monitoring: CHGA antibodies aid in tracking tumor burden and recurrence via IHC or serum assays .
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Therapeutic Resistance: Elevated CHGA levels may predict resistance to somatostatin analogs in NETs .
Colon Cancer Biomarker Potential
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Early Detection: Reduced CHGA expression in early-stage colon cancer (vs. normal mucosa) offers high sensitivity (89%) and specificity (89%) .
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Diagnostic Algorithms: Combining CHGA with markers like MKI67 or TP53 could improve accuracy in multi-biomarker panels .
Research Advances and Future Directions
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Genetic Regulation: CHGA promoter haplotype 2’s interaction with c-Rel transcription factor enhances expression, linking CHGA to inflammation and hypoxia .
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Translational Applications: CHGA’s role in vesicle biogenesis and monoamine storage suggests therapeutic targets for metabolic disorders and neuroendocrine diseases .
Product Specs
Product Science Overview
CgA is a 49 kDa protein consisting of 457 amino acids and is encoded by the CHGA gene located on chromosome 14 . It is predominantly produced by neuroendocrine cells and is present in various tissues, including the adrenal medulla, pancreatic islets, and the gastrointestinal tract . CgA is released into the bloodstream in response to extracellular stimulation, making it a valuable biomarker for neuroendocrine tumors .
CgA is widely used as a biomarker in the diagnosis and prognosis of neuroendocrine tumors, such as carcinoid tumors, pheochromocytomas, and paragangliomas . Its high specificity for neuroendocrine cells makes it an excellent marker for identifying these tumors through immunohistochemistry (IHC) and other diagnostic techniques .
The Mouse Anti-Human Chromogranin A antibody is a monoclonal antibody developed to specifically detect human CgA. This antibody is produced by immunizing mice with recombinant human CgA protein, leading to the generation of hybridoma cells that produce the desired monoclonal antibody . The antibody is then purified from the ascites fluid of these mice and characterized for its specificity and sensitivity .
The Mouse Anti-Human Chromogranin A antibody is used in various research and diagnostic applications, including:
- Immunohistochemistry (IHC): This technique involves staining tissue sections with the antibody to detect the presence and distribution of CgA in neuroendocrine cells .
- Western Blotting: The antibody is used to detect CgA in protein samples separated by gel electrophoresis .
- Immunocytochemistry/Immunofluorescence (ICC/IF): These techniques involve staining cells with the antibody to visualize CgA localization within cells .
