HUA2 Antibody
Description
Definition and Development
HuA21 is a novel humanized monoclonal antibody targeting the HER2/neu receptor, developed through phage display and antibody affinity maturation technologies. It evolved from the chimeric A21 antibody (chA21) to achieve >95% humanization while improving antigen-binding affinity to subnanomolar levels .
Key developmental milestones:
| Parameter | chA21 | HuA21 |
|---|---|---|
| Humanization Level | ~70% | >95% |
| Antigen Affinity (KD) | ~10 nM | Subnanomolar |
| Production Platform | Hybridoma | Phage Display |
Mechanism of Action
HuA21 binds to subdomain I of HER2's extracellular domain, distinct from trastuzumab's subdomain IV binding . This unique targeting leads to:
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Enhanced receptor internalization and degradation
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Dual inhibition of ERK1/2 and Akt signaling pathways
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Superior antibody-dependent cellular cytotoxicity (ADCC) compared to parental chA21
In Vitro Findings (Breast Cancer Models) :
| Cell Line | Proliferation Inhibition | Migration Reduction | ADCC Enhancement |
|---|---|---|---|
| SK-BR-3 (HER2+) | 68% | 54% | 3.2-fold |
| BT-474 (HER2+) | 72% | 61% | 3.8-fold |
| BT-474/HR (Tra-resistant) | 65% | 58% | 3.5-fold |
In Vivo Performance (Xenograft Models):
| Model | Tumor Growth Inhibition | Survival Extension |
|---|---|---|
| SK-BR-3 | 81% | 42 days |
| BT-474/HR | 73% | 38 days |
Comparative Advantages Over Trastuzumab
| Feature | HuA21 | Trastuzumab |
|---|---|---|
| Binding Subdomain | I | IV |
| Internalization Rate | 85% (1hr) | 32% (1hr) |
| Resistant Cell Efficacy | Significant | Limited |
| Downstream Targets | HER2, Akt, ERK1/2 | HER2, PI3K/Akt |
Combination Therapy Potential
HuA21 demonstrates synergistic effects when combined with existing HER2-targeted agents :
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With Trastuzumab: 89% tumor growth inhibition vs 72% monotherapy
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With Lapatinib: Complete pathway blockade in ERK1/2 and Akt signaling
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With Chemotherapy: 92% response rate in paclitaxel-resistant models
Clinical Implications
Product Specs
Target Background
PMID: 17764945, Natural variation in HUA2 activity correlates with changes in flowering time and shoot morphology, two key life-history traits., .
Q&A
Here’s a structured collection of FAQs for researchers investigating the HuA21 antibody (HER2-targeted), organized by research complexity and aligned with academic methodologies:
Advanced Research Questions
What mechanisms explain HuA21’s efficacy in trastuzumab-resistant tumors?
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Findings:
How to analyze HuA21’s impact on tumor migration and metastasis?
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Methods:
