GATA3 Antibody
Description
Definition and Function of GATA3 Antibody
GATA3 antibodies are immunological tools designed to detect the GATA3 transcription factor, a 48–55 kDa nuclear protein critical for T-cell development, luminal epithelial differentiation, and immune regulation . These antibodies are primarily used in diagnostic pathology to identify GATA3 protein expression in tissues, aiding in the classification of cancers such as breast, urothelial, and salivary gland carcinomas .
Applications in Research and Diagnostics
GATA3 antibodies are employed in diverse experimental and clinical settings:
Diagnostic Utility:
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Breast Cancer: GATA3-L (clone L50-823) outperforms GATA3-H (HG3-31) in triple-negative breast cancers (TNBC), detecting 66% vs. 44% of cases .
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Urothelial Carcinoma: Distinguishes metastatic urothelial carcinoma from prostatic adenocarcinoma and squamous cell carcinoma .
Tumor-Specific Expression
Immune Modulation:
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In bladder cancer, low GATA3 expression inversely correlates with immune checkpoint inhibitors (PD-L1, PD-1) and tumor-infiltrating lymphocytes (TILs), suggesting immunosuppressive roles .
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High GATA3 in triple-positive breast cancer (ER+/HER2+/PR+) may reduce immune infiltration, linking to poorer outcomes .
Antibody Specificity and Cross-Reactivity
Validation Challenges:
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Antibody performance varies by tumor type: GATA3-L shows higher sensitivity in TNBC (66%) than GATA3-H (44%) .
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Normal tissue expression (e.g., thymus, parathyroid) must be excluded to avoid false positives .
Clinical and Prognostic Implications
Therapeutic Implications:
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GATA3’s role in Th2 cell differentiation and allergy/immune responses has sparked interest in targeting GATA3 for autoimmune therapies .
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In cancer, GATA3’s dual role (tumor suppressor vs. immune modulation) complicates therapeutic strategies .
Challenges and Future Directions
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Standardization: Variability in staining protocols affects diagnostic reproducibility .
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Therapeutic Targeting: siRNA/DNAzyme delivery and post-translational modification strategies are under exploration to modulate GATA3 pathways .
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Immune Checkpoint Synergy: Studies are needed to assess whether GATA3 status predicts response to immunotherapies like PD-1/PD-L1 inhibitors .
Product Specs
Target Background
Q&A
GATA3 antibodies are critical tools in cancer research, particularly for studying transcriptional regulation and tumor differentiation. Below are structured FAQs addressing common methodological and research challenges, supported by experimental data and validation approaches from recent studies.
What are the primary applications of GATA3 antibodies in experimental workflows?
GATA3 antibodies are widely used for:
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Immunohistochemistry (IHC): Identifying GATA3 expression in tumor tissues (e.g., breast cancer, urothelial carcinoma) .
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Western blot (WB): Detecting full-length (~48–55 kDa) and splice variants (~37–40 kDa) in cell lysates .
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Immunofluorescence (IF): Localizing nuclear GATA3 in cultured cells (e.g., MCF-7) .
Methodological considerations:
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Antibody validation: Cross-validate using RNA-seq or independent antibodies (IWGAV guidelines) .
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Dilution optimization: Refer to manufacturer protocols (e.g., 1:1,000–1:6,000 for WB, 1:300–1:1,200 for IF) .
| Application | Recommended Dilution | Observed Reactivity |
|---|---|---|
| Western Blot | 1:1,000–1:6,000 | Human, mouse |
| IF/ICC | 1:300–1:1,200 | MCF-7 cells |
How to validate GATA3 antibody specificity in IHC?
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Multi-platform validation: Compare IHC results with RNA-seq (e.g., GTEx, FANTOM5) or flow cytometry .
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Epitope retrieval: Use heat-induced methods with citrate buffer (pH 6.0) for formalin-fixed tissues .
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Controls: Include GATA3-positive (thymus, breast cancer) and negative (non-keratinizing epithelia) tissues .
How to resolve discrepancies in GATA3 expression across tumor subtypes?
Conflicting reports (e.g., basal vs. squamous cell carcinoma) arise from:
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Staining sensitivity: Antibody clones (e.g., 634913 vs. AF2605) detect varying epitope accessibility .
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Tumor heterogeneity: GATA3 levels correlate with differentiation (e.g., reduced in HER2+ breast cancers) .
| Tumor Type | GATA3 Positivity Rate | Key Confounding Factor |
|---|---|---|
| Basal cell carcinoma | 97% | High in keratinizing layers |
| Squamous cell carcinoma | 16% | Sampling site variability |
What experimental strategies address splice variant detection in Western blots?
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Gel electrophoresis: Use 10–12% SDS-PAGE to distinguish full-length (48–55 kDa) and splice forms (37–40 kDa) .
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Lysate preparation: Include protease inhibitors to prevent degradation (e.g., in MCF-7 cells) .
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Antibody selection: Opt for clones targeting conserved N-terminal epitopes (e.g., MAB6330) .
How to interpret reduced GATA3 expression in prognostic studies?
In breast cancer, low GATA3 correlates with:
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Survival analysis: Use Cox regression with IHC H-scores (HR = 1.8 for low vs. high expressers) .
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Mechanistic follow-up: Pair with ChIP-seq to assess downstream target dysregulation (e.g., FOXA1) .
Why do GATA3 positivity rates vary between studies?
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Antibody validation rigor: Studies using IWGAV-compliant protocols report lower positivity in squamous cell carcinomas (16% vs. 81–88% in non-validated studies) .
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Scoring criteria: Thresholds for "positive" staining (e.g., >10% nuclei vs. H-score >50) impact rates .
Recommendation: Standardize scoring using digital pathology platforms (e.g., QuPath) and pre-validate antibodies across ≥3 independent labs .
