H2AFZ Antibody
Description
Definition and Biological Context
H2AFZ antibodies target the H2A.Z histone variant, a replication-independent histone involved in chromatin remodeling, transcriptional regulation, and genome stability . H2A.Z exists in two isoforms (H2A.Z.1 and H2A.Z.2), with H2AFZ encoding H2A.Z.1 . Dysregulation of H2A.Z is linked to tumor progression, immune evasion, and chemotherapy resistance .
Antibody Characteristics
Commercial H2AFZ antibodies vary in host species, reactivity, and applications. Key examples include:
These antibodies are validated for specificity, with immunogens often derived from synthetic peptides or recombinant proteins (e.g., amino acids 116–128 of human H2A.Z) .
Cancer Biomarker Studies
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Hepatocellular Carcinoma (HCC): H2AFZ overexpression correlates with TP53 mutations, aggressive tumor behavior, and poor prognosis. Antibodies detected elevated H2A.Z levels in HCC tissues, linking it to cell cycle dysregulation (e.g., PLK1, CDK1/2) and immune checkpoint gene co-expression (PD-L1, CTLA-4) .
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Lung Adenocarcinoma (LUAD): H2AFZ antibodies identified overexpression in LUAD tissues, associated with advanced tumor stage and myeloid-derived suppressor cell (MDSC) infiltration .
Functional Mechanisms
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Cell Cycle Regulation: H2A.Z.1 depletion induces G1 arrest and senescence, while H2A.Z.2 ensures centromere integrity during mitosis .
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Immune Modulation: In HCC, H2AFZ-high tumors exhibit increased CD4+ T cells, macrophages, and checkpoint molecule expression, suggesting sensitivity to immunotherapy .
Technical Validation
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Immunohistochemistry: Robust staining in tumor nuclei correlates with advanced disease .
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ChIP-Seq: Active Motif’s antibodies enable genome-wide mapping of H2A.Z-enriched regions, critical for studying epigenetic regulation .
Key Research Findings
Product Specs
Target Background
- H2A.Z is linked to epigenetic gene activation in prostate cancer. Acetylated H2A.Z contributes to the activation of newly formed enhancers in prostate cancer. PMID: 29116202
- Research indicates that H2A.Z is overexpressed in Intrahepatic Cholangiocarcinoma (ICC) and its expression is associated with a poor prognosis for patients with ICC. H2A.Z regulates cell proliferation in vitro and in vivo through the H2A.Z/S-phase kinase-associated protein 2/p27/p21 signaling pathway. PMID: 29532867
- A recent study identified GAS41 as a histone acetylation reader that promotes histone H2A.Z deposition in non-small cell lung cancer. PMID: 29437725
- Research suggests two possible modes of pioneering associated with combinations of H2A.Z and p300/CBP at nucleosome-occupied enhancers. PMID: 28301306
- Findings indicate that the accumulation of H2A.Z within repressed genes can be a consequence of the repression of gene transcription rather than an active mechanism required to establish the repression. PMID: 29036442
- Results suggest the oncogenic potential of H2A.Z.1 in liver tumorigenesis and that it plays a significant role in accelerating cell cycle transition and epithelial-mesenchymal transition (EMT) during hepatocarcinogenesis. PMID: 26863632
- Crystal structure results demonstrate that the flexible nature of the H2A.Z L1 loop plays a crucial role in forming the stable heterotypic H2A.Z/H2A nucleosome. PMID: 27358293
- Monoubiquitination of histone H2B prevents the eviction of histone variant H2A.Z from inducible enhancers. PMID: 27692985
- PWWP2A is identified as a novel H2A.Z-specific multivalent chromatin binder, establishing a surprising link between H2A.Z, chromosome segregation, and organ development. PMID: 28645917
- SMYD3-mediated H2A.Z.1K101 dimethylation activates cyclin A1 expression and contributes to driving the proliferation of breast cancer cells. PMID: 27569210
- Results suggest that the N-terminal tail of H2A.Z makes distinct contributions to epigenetic events. PMID: 26833946
- The H2AFZ gene may be associated with an increased risk of schizophrenia and contribute to the impairment of executive function in Han Chinese patients with schizophrenia. PMID: 26246156
- The 2.7-A-resolution crystal structure of the human YL1-H2A.Z-H2B complex reveals that YL1 binding, similar to ANP32E binding, triggers an extension of the H2A.Z alphaC helix. PMID: 26974126
- The primary function of INO80 and ANP32E in promoting homologous recombination is the removal of H2A.Z from chromatin. PMID: 26142279
- Research demonstrated a male-specific association of the H2AFZ gene with schizophrenia, suggesting that modifications to the H2AFZ signaling pathway warrant further investigation in the context of schizophrenia pathophysiology. PMID: 25392085
- Dynamic modulation of H2A.Z exchange and removal by Anp32e highlights the importance of the nucleosome surface and nucleosome dynamics in processing the damaged chromatin template during DNA double-strand break repair. PMID: 26034280
- Findings suggest that H2A.Z.2 acts as a mediator of cell proliferation and drug sensitivity in malignant melanoma. PMID: 26051178
- The predictive values associated with low expressions of H2AFZ and CASP8AP2 and high white blood cell count suggest that these features could help identify patients at a greater risk of relapse. PMID: 24397596
- Anp32e may assist in resolving non-nucleosomal H2A.Z aggregates and facilitate the removal of H2A.Z at the +1 nucleosomes. This removal could potentially aid RNA polymerase II in passing the first nucleosomal barrier. PMID: 24613878
- A study mapped H2A.Z genome-wide in embryonic stem cells and neural progenitors. H2A.Z is deposited at promoters and enhancers, and shows a strong correlation with H3K4 methylation. H2A.Z is present at poised promoters with bivalent chromatin and at active promoters with H3K4 methylation, but is absent from stably repressed promoters that are enriched for H3K27 trimethylation. PMID: 23034477
- Depletion of H2A.Z in the osteosarcoma U2OS cell line and in immortalized human fibroblasts does not alter parameters of DNA double-strand breaks repair while affecting clonogenic ability and cell cycle distribution. PMID: 24240188
- Mutational analysis revealed that the amino acid difference at position 38 is at least partially responsible for the structural polymorphism in the L1 loop region of H2A.Z.1 and H2A.Z.2. PMID: 24311584
- Sirt1 and H2A.Z deregulation in prostate cancer are related. Epigenetic mechanisms, primarily histone post-translational modifications, are likely involved in impairing sirt1-mediated downregulation of H2A.Z via proteasome-mediated degradation. PMID: 24127549
- H2A.Z-dependent crosstalk between enhancers and promoters regulates cyclin D1 expression. PMID: 23108396
- SETD6 monomethylates H2AZ on lysine 7. PMID: 23324626
- Data demonstrate that histone deacetylase inhibitors (HDACi) induce p21 transcription and reduce cell proliferation of MDA-MB231, an ERalpha-negative mammary tumor cell line, in an H2A.Z-dependent manner. PMID: 23349794
- Data suggest that histone H2A.Z is capable of specifically binding ST1926. PMID: 23245330
- Age-dependent p400 downregulation and loss of H2A.Z localization may contribute to the onset of replicative senescence through a sustained high rate of p21 transcription. PMID: 23146670
- H2A.Z exchange promotes specific patterns of histone modification and reorganization of the chromatin architecture, leading to the assembly of a chromatin template that is an efficient substrate for the DNA double-strand break repair machinery. PMID: 23122415
- ZNF24 may be implicated in transcriptional regulation of genes associated with oncogenesis through its interaction with H2A.Z. PMID: 22678762
- The incorporation of histone variant H2A.Z at the promoter regions of PPARgamma target genes by p400/Brd8 is essential for fat cell differentiation. PMID: 23064015
- Nucleosomes containing H2AZ are primarily composed of H4 K12ac and H3 K4me3, but not H3 K36me3. PMID: 22393239
- The short forms of H2A.Z in both yeast and human cells are more loosely associated with chromatin than the full-length proteins, indicating a conserved function for the H2A.Z C-terminal tail in regulating the association of H2A.Z with nucleosomes. PMID: 22493515
- Acetylation of H2A.Z is a key modification associated with gene activity in normal cells and epigenetic gene deregulation in tumorigenesis. PMID: 21788347
- H2A.Z is maintained during mitosis and marks the +1 nucleosome of active genes, which shifts during mitosis, resulting in occupancy at the transcriptional start site and a reduced nucleosome-depleted region. PMID: 20864037
- This review provides a brief overview of H2A.Z biology and presents hypotheses that could reconcile contradictory reports regarding the influence of H2A.Z on nucleosome stability. PMID: 20364108
- Estrogen Receptor alpha directly associates with the H2A.Z promoter, subsequently modulating its expression. PMID: 20023423
- Chromatin remodeling at the c-myc gene involves the local exchange of histone H2A.Z. PMID: 15878876
- Neither H2AZ itself nor other features of the H2AZ-containing nucleosome spread to the neighboring nucleosomes in vivo, suggesting that H2AZ does not function as a self-perpetuating epigenetic mark. PMID: 16809769
- The essential histone variant H2A.Z has been identified as a new structural component of the centromere. PMID: 17194760
- Monoubiquitylation of H2A.z distinguishes its association with euchromatin or facultative heterochromatin. PMID: 17636032
- Upon DNA damage, histone H2A.Z is first evicted from the p21 promoter, followed by the recruitment of the Tip60 histone acetyltransferase to activate p21 transcription. PMID: 17671089
- Histone variant H2A.Z is associated with breast cancer progression. PMID: 18414489
- Results demonstrate that H2A.Z nucleosomes protect only approximately 120 bp of DNA from MNase digestion and exhibit specific sequence preferences, suggesting a novel mechanism of nucleosome organization for the H2A.Z variant. PMID: 19246569
- Both genetic and epigenetic features likely participate in targeting H2A.Z to distinct chromatin loci. PMID: 19261190
- The nucleosome destabilizing effect of H2A.Z acetylation occurs synergistically with the acetylation of the rest of the core histones. PMID: 19385636
- H2A.Z is incorporated into the promoter regions of estrogen receptor (ERalpha) target genes only upon gene induction, and that, in a cyclic pattern. PMID: 19515975
- Research indicates that upon gene induction, human H2A.Z associates with gene promoters and assists in recruiting the transcriptional machinery. PMID: 19834540
- Both H2A.Z and H3.3 affect nucleosome positioning, either creating new positions or altering the relative occupancy of existing nucleosome position space. Only H2A.Z-containing nucleosomes exhibit altered linker histone binding. PMID: 19856965
Q&A
What experimental validations are essential for confirming H2AFZ antibody specificity in chromatin immunoprecipitation (ChIP) assays?
To ensure antibody specificity, researchers should employ a multi-modal validation strategy:
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Knockdown controls: Use siRNA or CRISPR-Cas9 to reduce H2AFZ expression, followed by Western blotting to confirm reduced signal .
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Cross-reactivity tests: Compare antibody binding in wild-type versus H2AFZ-knockout cell lines using immunofluorescence.
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Epitope mapping: Validate against recombinant H2AFZ protein fragments to identify recognized domains.
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Orthogonal validation: Correlate ChIP-seq results with H2AFZ mRNA expression levels from RNA-seq data in platforms like TCGA-LUAD .
A study analyzing LUAD tissues demonstrated that H2AFZ antibody validation required concordance between IHC scores and RNA-seq data (Pearson’s r = 0.82, p < 0.001) .
How should researchers optimize immunohistochemistry (IHC) protocols for H2AFZ in formalin-fixed paraffin-embedded (FFPE) tissues?
Critical parameters for IHC optimization include:
Validation requires comparison with negative controls (primary antibody omission) and quantitative scoring by two independent pathologists (Cohen’s κ > 0.75) .
What statistical methods are appropriate for analyzing H2AFZ expression correlations with clinical outcomes?
For survival analysis:
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Stratification: Divide cohorts into high/low H2AFZ groups using median expression (TCGA-LUAD cutoff = 7 IHC score) .
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Survival curves: Apply Kaplan-Meier analysis with log-rank testing (e.g., p = 0.003 for OS in HCC) .
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Multivariate adjustment: Use Cox regression to control for stage, age, and sex (HR = 2.1 for high H2AFZ in LUAD) .
In HCC, H2AFZ overexpression correlated with reduced OS (median 23 vs. 65 months, p < 0.001) .
How can conflicting data on H2AFZ’s role in tumor progression be resolved across studies?
Address discrepancies through:
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Cohort stratification: Analyze H2AFZ’s impact by molecular subtype (e.g., TP53-mutant vs. wild-type HCC). In TP53-mutant HCC, H2AFZ overexpression increased proliferation (EdU+ cells: 42% vs. 18%, p < 0.01) .
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Platform harmonization: Normalize mRNA (FPKM) and protein (IHC) data using z-scores for cross-study comparisons.
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Pathway contextualization: Perform GSEA to identify co-regulated pathways (e.g., cell cycle in LUAD vs. immune infiltration in HCC) .
A meta-analysis of 10 HCC cohorts revealed H2AFZ’s dual role: pro-proliferative in TP53-mutant contexts (p = 0.007) but immunomodulatory in microsatellite-stable tumors .
What experimental designs are optimal for investigating H2AFZ’s interplay with immune checkpoint regulators?
Use a multi-omics framework:
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Transcriptomic profiling: Correlate H2AFZ levels with PD-L1 (CD274), CTLA-4, and TIM-3 via RNA-seq (Spearman’s ρ = 0.68 in HCC) .
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Spatial analysis: Combine multiplex IHC for H2AFZ and CD8+ T cells to map immune evasion niches.
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Pharmacological perturbation: Treat H2AFZ-high organoids with anti-PD-1 and monitor γH2AX foci as a DNA damage readout.
In TCGA-LIHC, H2AFZ-high tumors showed elevated macrophage infiltration (CIBERSORT p = 0.02) and PD-L1 expression (log2FC = 1.8) .
How should researchers contextualize H2AFZ’s prognostic value against established biomarkers?
Develop integrated risk models:
| Biomarker | AUC (5-year OS) | Hazard Ratio | Cohort |
|---|---|---|---|
| H2AFZ | 0.74 | 2.1 | TCGA-LUAD |
| TP53 mutation | 0.68 | 1.8 | TCGA-LIHC |
| PD-L1 | 0.71 | 1.6 | GSE68465 |
Incorporate H2AFZ into nomograms with clinical stage and mutational status. For HCC, H2AFZ/TP53 co-alterations reduced median OS to 14 months (vs. 28 months for TP53-only, p = 0.004) .
How to address batch effects in multi-center H2AFZ IHC studies?
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Pre-analytical controls: Standardize fixation (10% NBF, 24 hr) and section thickness (4 µm).
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Reference standards: Include H2AFZ-high/low cell line pellets in each batch.
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Digital pathology: Use Visiopharm® for batch-corrected densitometry (CV < 12%) .
What bioinformatics pipelines robustly link H2AFZ ChIP-seq data to transcriptional outputs?
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Peak calling: Use MACS2 with q < 0.01 and fold-change > 2.
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Motif analysis: Apply HOMER to identify E2F1 binding sites (enriched in H2AFZ-high HCC, p = 3e-5) .
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Integration: Overlay ATAC-seq data to distinguish direct chromatin remodeling effects.
In LUAD, H2AFZ peaks overlapped with 62% of super-enhancers regulating MYC and KRAS .
