POLR2C Antibody

What applications are validated for POLR2C antibody in experimental research?

POLR2C antibody has been validated for multiple experimental applications including Western Blot (WB), Immunoprecipitation (IP), Immunohistochemistry (IHC), and ELISA. Positive Western Blot detection has been confirmed in mouse kidney tissue and HeLa cells, while IP applications have been validated in HeLa cells. For IHC applications, the antibody has been successfully used with human cervical cancer tissue . When designing experiments using this antibody, researchers should prioritize applications with published validation data to ensure reliable results. The antibody demonstrates specific binding to the 33kDa POLR2C protein, making it suitable for investigating RNA Polymerase II complex formation and function.

What are the optimal dilution parameters for different applications of POLR2C antibody?

The recommended dilution parameters vary significantly depending on the application technique:

These ranges provide starting points, but researchers should perform optimization titrations in their specific experimental systems to determine optimal concentrations. For IHC applications, antigen retrieval methodology significantly impacts results, with TE buffer pH 9.0 being the suggested method, though citrate buffer pH 6.0 may be used as an alternative . The optimal dilution can vary based on protein expression levels in different sample types, necessitating preliminary optimization experiments.

What species reactivity has been confirmed for POLR2C antibody?

The POLR2C antibody (13428-1-AP) has been tested and confirmed to react with human, mouse, and rat samples . Published literature has specifically cited reactivity with human and mouse samples. This multi-species reactivity makes the antibody valuable for comparative studies across model organisms. When working with other species, cross-reactivity should be experimentally validated before proceeding with full-scale experiments. The antibody targets a highly conserved region of the POLR2C protein, explaining its cross-species reactivity profile. Sequence alignment analysis of the POLR2C protein across species can provide predictive information about potential reactivity in untested species.

How should POLR2C antibody be stored to maintain optimal activity?

The recommended storage conditions for maintaining POLR2C antibody activity are -20°C in PBS with 0.02% sodium azide and 50% glycerol at pH 7.3 . The antibody remains stable for one year after shipment when stored properly. Unlike some antibodies that require aliquoting to prevent freeze-thaw cycles, the buffer composition for this particular preparation makes aliquoting unnecessary for -20°C storage. For the 20μl size preparation, it's important to note it contains 0.1% BSA which may affect certain applications. Researchers should avoid repeated freeze-thaw cycles despite the stabilizing buffer, as this can potentially reduce antibody performance over time. Any changes in appearance such as particulate formation or cloudiness may indicate reduced activity.

How does POLR2C expression correlate with clinical outcomes in cancer research?

Univariate analysis demonstrates that POLR2C is a significant unfavorable prognostic factor with hazard ratios of 1.574 (95% CI: 1.230–2.015, P<0.001) for OS and 1.543 (95% CI: 1.191–1.998, P=0.001) for PFI . This robust statistical association makes POLR2C a valuable biomarker for predicting patient outcomes. The table below shows hazard ratios for POLR2C compared to other RNA polymerase subunits:

These findings suggest that when using POLR2C antibody for prognostic studies, researchers should consider correlated analysis with clinical variables and other RNA polymerase subunits to develop comprehensive prognostic signatures.

What is the YY1-POLR2C regulatory axis and how can it be studied using POLR2C antibody?

The YY1-POLR2C regulatory axis represents a critical transcriptional control mechanism with significant implications for cancer biology. Comprehensive multi-omics analysis has revealed that POLR2C expression appears to be transcriptionally regulated by the Yin Yang 1 (YY1) transcription factor . This regulatory relationship drives cell-cycle dysregulation and malignant proliferation in head and neck squamous cell carcinoma.

To investigate this axis, researchers can employ POLR2C antibody in several methodological approaches:

• Chromatin Immunoprecipitation (ChIP) assays using both YY1 and POLR2C antibodies to confirm direct binding of YY1 to the POLR2C promoter region

• Co-immunoprecipitation (Co-IP) experiments to identify protein interaction partners within this regulatory network

• Sequential ChIP (ChIP-reChIP) to determine co-occupancy of YY1 and other transcription factors at the POLR2C promoter

• Western blot analysis following YY1 knockdown or overexpression to quantify resulting changes in POLR2C protein levels

When designing these experiments, researchers should consider the subcellular localization of POLR2C, which is predominantly found in the nucleoplasm and cytosol . This localization pattern requires appropriate fractionation protocols when isolating nuclear and cytoplasmic compartments for immunoprecipitation or western blotting.

How can POLR2C antibody be utilized to investigate the role of POLR2C in immune modulation and tumor microenvironment?

Recent research has uncovered a critical role for POLR2C in shaping the tumor microenvironment (TME) and facilitating immune evasion. To investigate these functions, POLR2C antibody can be employed in several sophisticated methodological approaches:

• Multiplex Immunohistochemistry (mIHC) or Immunofluorescence (mIF): Using POLR2C antibody alongside immune cell markers can reveal spatial relationships between POLR2C-expressing tumor cells and infiltrating immune populations. This technique requires careful antibody panel design, including CD8+ T cells, regulatory T cells, and myeloid-derived suppressor cells markers.

• Single-cell Analysis: Combining POLR2C antibody staining with single-cell RNA sequencing (scRNA-seq) or cytometry by time of flight (CyTOF) allows researchers to correlate POLR2C expression with immune cell phenotypes at single-cell resolution.

• Spatial Transcriptomics: Integrating POLR2C antibody staining with spatial transcriptomic techniques can map the relationship between POLR2C expression and immune cell distribution within the tumor microenvironment.

Research indicates that high POLR2C expression negatively correlates with immune cell infiltration and facilitates immune evasion mechanisms . Mechanistic studies demonstrate that POLRs, including POLR2C, mediate frequent interactions between malignant and immune cells, potentially contributing to resistance to immunotherapy . These findings suggest POLR2C may represent a novel immunomodulatory target in cancer therapeutics.

What are the methodological considerations for resolving contradictory POLR2C expression data across different cancer types?

When researchers encounter contradictory data regarding POLR2C expression across different cancer types, several methodological approaches can help resolve these discrepancies:

• Multi-platform Validation: Employ multiple techniques to validate POLR2C expression, including western blotting, RT-qPCR, and immunohistochemistry using the same POLR2C antibody. Each method has distinct sensitivity and specificity profiles, and concordance across platforms strengthens confidence in results.

• Isoform-specific Analysis: POLR2C may have multiple isoforms with variable expression patterns across cancer types. Researchers should design primers or use antibodies that can differentiate between isoforms to determine if discrepancies relate to isoform-specific expression patterns.

• Subcellular Localization Analysis: Since POLR2C is predominantly located in the nucleoplasm and cytosol , differential subcellular distribution might explain contradictory findings. Using fractionation protocols followed by western blotting or immunofluorescence with the POLR2C antibody can reveal cancer-specific localization patterns.

• Context-dependent Expression Analysis: POLR2C expression may be influenced by tumor microenvironment factors. Analyzing expression in relation to hypoxia markers, inflammatory signals, or stromal components can contextualize seemingly contradictory results.

• Technical Considerations: When comparing results across studies, researchers should carefully evaluate antibody clones used, epitope targets, fixation protocols for IHC, and normalization methods for quantitative analysis, as these factors significantly impact comparability.

By implementing these methodological approaches, researchers can systematically address contradictions in POLR2C expression data and develop a more nuanced understanding of its role across different cancer contexts.

What are the most common technical issues when using POLR2C antibody for IHC and how can they be resolved?

When using POLR2C antibody for immunohistochemistry applications, researchers frequently encounter several technical challenges that can be systematically addressed:

• Inconsistent Staining Intensity: This often results from suboptimal antigen retrieval. For POLR2C antibody, TE buffer at pH 9.0 is specifically recommended, though citrate buffer at pH 6.0 can serve as an alternative . Researchers should systematically compare both methods, adjusting both temperature and duration of retrieval to optimize signal recovery while maintaining tissue integrity.

• High Background Staining: This may occur due to insufficient blocking or overly concentrated primary antibody. Implement a titration series beginning with the recommended 1:20-1:200 dilution range to determine the optimal concentration for your specific tissue type. Extended blocking steps with 5-10% normal serum matching the host species of the secondary antibody can reduce non-specific binding.

• False Negative Results: These may occur in samples with low POLR2C expression. Amplification systems such as tyramide signal amplification (TSA) can enhance sensitivity without compromising specificity. Additionally, consider using fresh tissue samples, as POLR2C epitopes may degrade during prolonged storage.

• Inconsistent Results Between Experiments: Standardize all aspects of the protocol including fixation time, section thickness (4-5μm recommended), and incubation periods. Incorporating positive control tissues with known POLR2C expression (such as human cervical cancer tissue ) in each run allows for internal validation.

• Nuclear vs. Cytoplasmic Staining: Since POLR2C localizes to both nucleoplasm and cytosol , inconsistent subcellular staining patterns may occur. Optimize permeabilization conditions to ensure antibody access to nuclear epitopes, while carefully documenting both nuclear and cytoplasmic staining patterns for comprehensive analysis.

How can researchers validate the specificity of POLR2C antibody results in their experimental systems?

Validating antibody specificity is crucial for ensuring reliable experimental outcomes. For POLR2C antibody, researchers should implement the following comprehensive validation strategies:

• Molecular Weight Confirmation: Western blot analysis should confirm detection of POLR2C at its expected molecular weight of 33 kDa . Any additional bands should be carefully investigated as potential isoforms, post-translational modifications, or non-specific binding.

• Positive and Negative Controls: Include tissues or cell lines with known high expression (HeLa cells, human cervical cancer tissue) and low/no expression of POLR2C . The staining pattern should align with previous reports of nucleoplasmic and cytosolic localization .

• Peptide Competition Assay: Pre-incubating the POLR2C antibody with its immunizing peptide (POLR2C fusion protein Ag4228 ) should abolish specific staining, confirming binding specificity.

• Genetic Models: In cell culture systems, CRISPR/Cas9-mediated POLR2C knockout or siRNA-mediated knockdown should result in reduced or absent signal. This genetic validation represents the gold standard for antibody specificity.

• Orthogonal Method Comparison: Results from the POLR2C antibody should be compared with alternative detection methods such as RNA-seq or RT-qPCR for POLR2C transcript levels, with concordance between protein and mRNA providing additional validation.

• Multiple Antibody Comparison: When available, comparing results from different antibody clones targeting distinct POLR2C epitopes can provide confirmation of specific detection.

• Cross-reactivity Assessment: When working with non-human samples, sequence alignment of the immunogen with the target species' POLR2C protein can predict potential cross-reactivity issues.

What methodology should be used to simultaneously investigate POLR2C and YY1 in experimental systems?

To investigate the YY1-POLR2C regulatory axis effectively, researchers should employ multi-modal approaches that reveal both physical interactions and functional relationships:

• Sequential Chromatin Immunoprecipitation (ChIP-reChIP): This technique can determine whether YY1 and POLR2C co-occupy the same genomic regions. The protocol involves:

  • Initial ChIP with YY1 antibody

  • Elution of the YY1-bound complexes

  • Secondary ChIP with POLR2C antibody

  • Analysis of co-occupied regions by qPCR or sequencing

• Proximity Ligation Assay (PLA): This advanced immunofluorescence technique can visualize YY1-POLR2C interactions at the single-molecule level within intact cells. The PLA signal only generates when the two proteins are within 40nm of each other, providing evidence of direct or indirect physical interaction.

• Co-Immunoprecipitation with Reciprocal Validation:

  • Perform IP with POLR2C antibody (0.5-4.0 μg for 1.0-3.0 mg of total protein lysate )

  • Probe for YY1 by western blot

  • Confirm with the reverse experiment (IP with YY1, probe for POLR2C)

  • Include appropriate IgG controls and input samples

• Functional Genomics Approach:

  • YY1 knockdown or overexpression followed by POLR2C protein quantification

  • POLR2C promoter-reporter assays with YY1 binding site mutations

  • ChIP-seq for both factors to identify genome-wide co-regulation patterns

• Single-cell Multi-omics:

  • Combined single-cell RNA-seq and ATAC-seq to correlate YY1 binding, chromatin accessibility, and POLR2C expression

  • Single-cell protein analysis using CyTOF with antibodies for both factors

When implementing these approaches, researchers should consider the subcellular localization of both proteins and employ appropriate nuclear extraction protocols to enrich for nuclear fractions where transcriptional regulation occurs. These methodologies provide complementary evidence for the YY1-POLR2C axis from different experimental perspectives.

How can POLR2C antibody be used in biomarker development for cancer prognostication?

POLR2C shows significant potential as a prognostic biomarker, particularly in head and neck squamous cell carcinoma where high expression correlates with poor clinical outcomes . To develop POLR2C as a clinical biomarker, researchers should implement the following methodological framework:

These methodological approaches transform POLR2C antibody from a research tool into a clinically relevant biomarker with potential applications in treatment stratification and prognostic assessment.

What is the methodological approach for investigating POLR2C's role in immunotherapy resistance?

Recent research suggests POLR2C may contribute to immunotherapy resistance by mediating malignant-immune cell interactions and promoting an immunosuppressive tumor microenvironment . To investigate this role, researchers should implement the following comprehensive methodological framework:

• Spatial Immunoprofiling: Use multiplex immunohistochemistry with POLR2C antibody alongside immune checkpoint markers (PD-1, PD-L1, CTLA-4) and immune cell markers to map spatial relationships. This approach requires:

  • Optimized antibody panels with compatible fluorophores

  • Multispectral imaging to separate overlapping signals

  • Computational analysis to quantify cell-cell interactions

• Longitudinal Biospecimen Analysis:

  • Collect pre-treatment and on-treatment biopsies from patients receiving immunotherapy

  • Analyze POLR2C expression patterns using standardized IHC protocols

  • Correlate changes in expression with treatment response and resistance development

• In Vitro Co-culture Systems:

  • Establish co-cultures of POLR2C-high and POLR2C-low cancer cells with immune cells

  • Measure immune effector functions (cytotoxicity, cytokine production)

  • Assess immune checkpoint expression and T cell exhaustion markers

• Immune Checkpoint Blockade in Genetic Models:

  • Generate POLR2C knockdown and overexpression models in immunocompetent mouse systems

  • Treat with immune checkpoint inhibitors

  • Monitor tumor growth, immune infiltration, and treatment response

• Mechanistic Studies:

  • Perform POLR2C immunoprecipitation followed by mass spectrometry to identify immune-regulatory binding partners

  • Use ChIP-seq to determine if POLR2C regulates genes involved in immune evasion

  • Investigate if the YY1-POLR2C axis directly regulates immune checkpoint gene expression

These methodological approaches can reveal whether POLR2C serves as a predictive biomarker for immunotherapy response and whether targeting the YY1-POLR2C axis might overcome resistance mechanisms, potentially establishing POLR2C as a therapeutic target for combination immunotherapy strategies.

How can advanced imaging techniques enhance POLR2C localization studies beyond conventional microscopy?

Conventional immunofluorescence has established that POLR2C protein is predominantly located in the nucleoplasm and cytosol , but advanced imaging techniques can provide deeper insights into its dynamic localization and functional interactions:

• Super-resolution Microscopy: Techniques such as Stimulated Emission Depletion (STED), Structured Illumination Microscopy (SIM), and Single-Molecule Localization Microscopy (SMLM) overcome the diffraction limit of conventional microscopy, allowing visualization of POLR2C distribution at nanoscale resolution (20-100nm). This enables:

  • Visualization of POLR2C within transcription factories

  • Detection of potential nuclear subcompartmentalization

  • Analysis of POLR2C clustering patterns in different cell states

• Live-cell Imaging with POLR2C Fusion Proteins:

  • CRISPR-mediated endogenous tagging of POLR2C with fluorescent proteins

  • Real-time tracking of POLR2C dynamics during transcription

  • Correlation with cellular processes like cell cycle progression

• Lattice Light-Sheet Microscopy:

  • Reduced phototoxicity for extended live imaging

  • Capture of POLR2C redistribution during cellular processes

  • Three-dimensional rendering of POLR2C localization patterns

• Correlative Light and Electron Microscopy (CLEM):

  • Initial identification of POLR2C by fluorescence microscopy

  • Ultra-structural context provided by electron microscopy

  • Gold-labeled secondary antibodies for precise localization

• Expansion Microscopy:

  • Physical expansion of fixed specimens

  • Enhanced resolution with standard confocal microscopy

  • Improved visualization of POLR2C spatial relationships with chromatin

When implementing these advanced techniques, researchers must optimize fixation protocols to preserve both antigenicity for POLR2C antibody binding and native protein localization patterns. Each approach provides complementary information about POLR2C's dynamic behavior in cellular contexts, extending beyond the static localization data currently available.

What methodologies should be employed to investigate post-translational modifications of POLR2C?

Post-translational modifications (PTMs) can significantly alter POLR2C function, but these modifications remain largely unexplored. To comprehensively investigate POLR2C PTMs, researchers should implement the following methodological approaches:

• IP-Mass Spectrometry Workflow:

  • Immunoprecipitate POLR2C using optimized conditions (0.5-4.0 μg antibody for 1.0-3.0 mg protein lysate )

  • Perform in-gel digestion with multiple proteases (trypsin, chymotrypsin, Glu-C) to maximize sequence coverage

  • Analyze by liquid chromatography-tandem mass spectrometry (LC-MS/MS)

  • Apply specific enrichment strategies for:

    • Phosphorylation (TiO₂, IMAC)

    • Ubiquitination (K-ε-GG antibody enrichment)

    • Acetylation (anti-acetyllysine antibody)

• Site-specific Mutational Analysis:

  • Generate point mutations at identified modification sites

  • Assess functional consequences on transcription and protein-protein interactions

  • Create phosphomimetic and non-phosphorylatable mutants to study phosphoregulation

• Site-specific PTM Antibody Development:

  • Design and validate antibodies against specific modified residues

  • Apply these in western blotting and IHC to map modification patterns across tissue types and disease states

• Proximity Labeling Coupled with PTM Analysis:

  • TurboID or APEX2 fusion with POLR2C to identify proximal kinases, phosphatases, or other modifying enzymes

  • Correlate enzyme proximity with modification status

• Drug Perturbation Studies:

  • Treat cells with kinase inhibitors, deacetylase inhibitors, or proteasome inhibitors

  • Monitor changes in POLR2C modification state, stability, and function

• Cell Cycle and Stress-Dependent Modification Analysis:

  • Synchronize cells at different cell cycle stages

  • Apply various stressors (oxidative, DNA damage, hypoxia)

  • Map dynamic changes in POLR2C modification patterns

When analyzing potential PTMs, researchers should consider how modifications might alter POLR2C's subcellular localization between nucleoplasm and cytosol and whether modification patterns differ between normal and cancer cells, particularly in HNSC where POLR2C has prognostic significance .