FH6 Antibody
Description
Applications in Cancer Research
FH6 is widely used to study tumor-associated antigens and their role in metastasis:
Expression in Cancer Tissues:
Prognostic Utility:
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In renal cell carcinoma (RCC), low FH6 and high CSLEX1 expression identify patients with 3.5× higher metastasis risk .
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Serum levels of FH6-reactive antigens are elevated in lung, liver, and pancreatic cancers compared to healthy controls .
Therapeutic Potential in Bacterial Infections
FH6-inspired fusion proteins (e.g., FH6,7/HuFc) show promise as anti-infective agents:
Mechanism of Action:
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FH6,7/HuFc: Combines human factor H (FH) domains 6–7 with IgG1 Fc to enhance complement activation on bacterial surfaces .
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Displaces native FH from pathogens, enabling uncontrolled complement-mediated lysis .
Efficacy in Preclinical Models:
Tissue-Specific Expression Patterns
Normal Tissues:
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Limited to granulocytes, monocytes, and fetal gastrointestinal epithelia (stomach, colon) .
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Absent in most adult tissues, including healthy gastrointestinal epithelia .
Cancer vs. Normal:
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Overexpressed in 44/76 cancer tissues (e.g., gastric, lung, breast) but undetectable in adjacent normal tissue .
Clinical and Research Protocols
Recommended Usage:
Formulation:
Key Research Findings
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Cancer Metastasis: FH6-reactive antigens facilitate hematogenous spread by binding E-selectin on endothelial cells .
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Complement Activation: FH6,7/HuFc enhances classical pathway activity, achieving 1.5–2 log<sub>10</sub> reductions in bacterial load .
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Differentiation Marker: High sLe<sup>x-i</sup> expression in tumors correlates with well-differentiated phenotypes .
Product Specs
Constituents: 50% Glycerol, 0.01M PBS, pH 7.4
Target Background
Q&A
Basic Research Questions
What antigenic determinant does FH6 antibody recognize, and how does this impact experimental design?
FH6 targets sialyl Lewis X-i (sialyl Lex-i), a difucoganglioside with the structure NeuAcα2→3Galβ1→4[Fucα1→3]GlcNAcβ1→3Galβ1→4[Fucα1→3]GlcNAcβ1→3Galβ1→4Glcβ1→1Cer . Key considerations:
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Specificity validation: Use knockout cell lines or enzymatic digestion (e.g., neuraminidase/fucosidase) to confirm target dependency .
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Tissue selection: Prioritize lung, breast, or pancreatic cancer tissues, which show higher FH6 reactivity (86% positivity in breast cancer vs. 50% in lung) .
Which methodologies are standard for FH6 antigen detection in serum vs. tissue samples?
Advanced Research Challenges
How to resolve contradictory FH6 reactivity data between cancer subtypes?
Discrepancies arise due to:
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Antigen heterogeneity: Gastric/colonic tumors show weaker FH6 staining vs. breast/lung cancers .
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Glycoform variability: FH6 detects glycolipids in tissues but binds glycoproteins (e.g., mucins) in serum .
Solution: Pair FH6 with orthogonal probes like FH4 (targets asialo core) to distinguish glycolipid vs. glycoprotein localization .
What strategies minimize spectral overlap when integrating FH6 into multi-marker flow cytometry panels?
How to validate FH6 specificity in 3D organoid models?
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Step 1: Perform competitive inhibition assays using synthetic sialyl Lex-i glycoconjugates .
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Step 2: Compare staining patterns with CSLEX1 (sialyl Leˣ-specific antibody) to rule off-target binding .
Methodological Insights from Published Data
Table 1: FH6 Positivity Rates in Human Cancers ( )
| Cancer Type | Positivity Rate | Staining Intensity |
|---|---|---|
| Breast | 86% | Strong, membranous |
| Lung | 50% | Moderate, cytoplasmic |
| Gastric | 32% | Weak, focal |
Table 2: Antigen Extraction Efficiency for Serum Analysis ( )
| Extraction Method | Recovery Rate | Interfering Substances Removed |
|---|---|---|
| 0.6 M PCA | 92% | Albumin, IgG |
| 7% TCA | 88% | Lipoproteins |
