ticrr Antibody

What is TICRR and what are its key functions in cellular processes?

TICRR (TopBP1-interacting checkpoint and replication regulator), also known as Treslin or SLD3, is an essential regulator of DNA replication initiation. It plays a critical role in determining the number of S-phase origins during cell cycle progression. TICRR levels are characteristically high during the G1 phase and decline sharply when cells enter the S phase and begin DNA replication . This protein has a molecular weight of approximately 210,857 Da and functions in regulatory pathways related to cell cycle progression . TICRR's expression and phosphorylation status serve as critical determinants of DNA replication dynamics, making it an important protein in studies of cell cycle regulation and oncogenesis .

How does TICRR expression vary across different tissue types and disease states?

Analysis of TICRR expression across multiple cancer types using TCGA and GTEx databases reveals significant variation. Among 33 cancer types analyzed, 24 showed higher TICRR expression compared to corresponding normal tissues, while only three exhibited lower expression . Specifically in cutaneous melanoma (CM), TICRR is significantly upregulated compared to healthy normal skin tissues at both mRNA and protein levels . This overexpression pattern appears consistent across multiple cancer types, suggesting TICRR may play a broad role in oncogenic processes rather than being limited to a specific cancer type.

What are the primary structural characteristics of anti-TICRR antibodies used in research?

Anti-TICRR antibodies used in research are predominantly polyclonal antibodies developed in rabbits. For example, the BosterBio anti-TICRR antibody (A08002) is a rabbit polyclonal IgG antibody generated using a 19-amino acid peptide near the carboxy terminus of human TICRR (located within amino acids 1840-1890) . These antibodies are typically affinity chromatography purified via peptide columns and supplied in PBS containing 0.02% sodium azide . The polyclonal nature provides broad epitope recognition, making these antibodies versatile for various applications including protein detection and localization studies.

What are the validated applications for anti-TICRR antibodies in experimental research?

Anti-TICRR antibodies have been validated for multiple experimental applications as outlined in the table below:

These applications enable comprehensive analysis of TICRR expression, localization, and interactions in both cellular and tissue contexts . For cancer research applications, IHC and IF have proven particularly valuable for assessing TICRR expression differences between tumor and normal tissues .

What are the recommended protocols for TICRR immunofluorescence staining in tissue samples?

For optimal immunofluorescence staining of TICRR in tissue samples, researchers should follow this methodological approach:

• Tissue Processing: Fix tissue samples in 10% neutral buffered formalin and embed in paraffin. Section at 4-6 μm thickness.

• Antigen Retrieval: Perform heat-induced epitope retrieval in citrate buffer (pH 6.0) for 20 minutes.

• Blocking: Block non-specific binding with 5% normal goat serum in PBS for 1 hour at room temperature.

• Primary Antibody Incubation: Dilute anti-TICRR antibody (1:100-1:200) in blocking buffer and incubate overnight at 4°C.

• Secondary Antibody: Apply fluorophore-conjugated secondary antibody (e.g., Alexa Fluor 488) at 1:500 dilution for 1 hour at room temperature.

• Counterstaining: Counterstain nuclei with DAPI (1:1000) for 5 minutes.

• Mounting: Mount slides with anti-fade mounting medium.

This protocol has been successfully employed to demonstrate TICRR overexpression in cutaneous melanoma tissues compared to healthy skin samples, as validated by quantitative analysis of fluorescence intensity .

How should researchers optimize Western blot conditions for TICRR detection?

For optimal Western blot detection of TICRR (molecular weight ~211 kDa), researchers should consider these technical parameters:

• Protein Extraction: Use RIPA buffer supplemented with protease and phosphatase inhibitors to ensure complete protein extraction and preservation.

• Gel Selection: Use 6-8% SDS-PAGE gels to effectively resolve high molecular weight proteins.

• Transfer Conditions: Perform wet transfer at low voltage (30V) overnight at 4°C to ensure complete transfer of large proteins.

• Blocking Conditions: Block membranes with 5% non-fat dry milk in TBST for 1 hour at room temperature.

• Antibody Dilution: Dilute anti-TICRR primary antibody 1:1000 in blocking solution and incubate overnight at 4°C.

• Washing Steps: Perform 4-5 washes with TBST, 5 minutes each, to reduce background.

• Detection Method: Use HRP-conjugated secondary antibodies with enhanced chemiluminescence for detection.

Include positive controls (cancer cell lines with known TICRR expression) and loading controls (β-actin or GAPDH) to ensure experimental validity and accurate quantification .

How can TICRR antibodies be utilized to study cell cycle regulation mechanisms?

TICRR antibodies can be employed to investigate cell cycle regulation through several advanced methodologies:

• Chromatin Immunoprecipitation (ChIP): Anti-TICRR antibodies can be used in ChIP assays to identify genomic regions where TICRR binds, particularly at replication origins. This provides insights into the spatiotemporal regulation of DNA replication initiation.

• Proximity Ligation Assays (PLA): To study TICRR interactions with other replication factors (e.g., TopBP1), PLA using anti-TICRR antibodies can visualize and quantify protein-protein interactions in situ.

• Flow Cytometry: Combining anti-TICRR antibody staining with DNA content analysis allows correlation between TICRR expression levels and cell cycle phases. Research has demonstrated that TICRR silencing prolongs the G0/G1 phase and shortens the G2/M phase in melanoma cells, suggesting its critical role in cell cycle progression .

• Immunoprecipitation-Mass Spectrometry (IP-MS): Anti-TICRR antibodies can precipitate TICRR and its associated protein complexes for subsequent identification by mass spectrometry, revealing novel interaction partners involved in cell cycle regulation.

These techniques collectively provide comprehensive insights into TICRR's mechanistic role in orchestrating DNA replication and cell cycle progression.

What approaches can be used to investigate TICRR's role in the PI3K/AKT/mTOR signaling pathway?

To elucidate TICRR's involvement in the PI3K/AKT/mTOR signaling pathway, researchers can implement these methodological approaches:

• Phospho-specific Western Blotting: Analyze phosphorylation status of key pathway components (p-PI3K, p-AKT, p-mTOR) following TICRR knockdown or overexpression. Research has shown that TICRR suppression attenuates activation of PI3K/AKT/mTOR signaling in melanoma cells .

• Rescue Experiments: Combine TICRR overexpression with specific pathway inhibitors (e.g., LY294002) to determine if the pro-proliferative effects of TICRR can be reversed. Studies have demonstrated that LY294002 treatment partially counteracts the proliferation-enhancing effects of TICRR overexpression .

• Co-immunoprecipitation (Co-IP): Use anti-TICRR antibodies to pull down TICRR and probe for PI3K/AKT pathway components to identify direct interactions.

• Immunofluorescence Co-localization: Perform dual staining with anti-TICRR and anti-p-AKT antibodies to assess subcellular co-localization, providing spatial information about potential interactions.

• Quantitative Phosphoproteomics: Compare phosphorylation patterns of pathway components in TICRR-manipulated versus control cells to identify specific phosphorylation events regulated by TICRR.

These approaches collectively provide comprehensive mechanistic insights into how TICRR modulates this critical oncogenic signaling pathway.

How can researchers utilize anti-TICRR antibodies to study tumor microenvironment interactions?

Anti-TICRR antibodies can be employed to investigate tumor microenvironment (TME) interactions through these specialized methodologies:

• Multiplex Immunofluorescence: Combine anti-TICRR antibodies with markers for various immune cell types (CD4, CD8, CD68, etc.) to simultaneously visualize and quantify TICRR expression and immune cell infiltration. Research has demonstrated TICRR co-expression with CD4 in melanoma tissues using this approach .

• Tissue Microarray Analysis: Apply anti-TICRR antibodies to tissue microarrays containing tumor samples and adjacent normal tissues to correlate TICRR expression with clinicopathological features and immune cell infiltration patterns.

• Single-cell Analysis: Combine anti-TICRR antibody staining with single-cell RNA sequencing to identify cell subpopulations with distinct TICRR expression profiles and correlate with immune signatures.

• Spatial Transcriptomics: Use anti-TICRR antibodies in conjunction with spatial transcriptomics to map TICRR expression in relation to immune cell localization within the tumor microenvironment.

Research has revealed significant correlations between TICRR expression and immune cell infiltration, including negative correlations with dendritic cells (DCs), plasmacytoid dendritic cells (pDCs), regulatory T cells (Tregs), cytotoxic T cells, and neutrophils, while showing positive correlation with T helper 2 (Th2) cells . These findings suggest TICRR may influence tumor immune evasion mechanisms.

What are common challenges when using TICRR antibodies in immunohistochemistry, and how can they be addressed?

Researchers may encounter several challenges when using TICRR antibodies for immunohistochemistry:

• High Background Staining:

  • Cause: Insufficient blocking or antibody concentration too high

  • Solution: Increase blocking time to 2 hours using 10% normal serum, and optimize antibody dilution (try 1:200-1:500)

• Weak or Absent Signal:

  • Cause: Inadequate antigen retrieval or epitope masking

  • Solution: Extend heat-induced epitope retrieval time to 30 minutes and test alternative retrieval buffers (EDTA pH 8.0 vs. citrate pH 6.0)

• Non-specific Staining:

  • Cause: Cross-reactivity with other proteins

  • Solution: Pre-absorb antibody with recombinant peptide or use more selective monoclonal antibodies

• Variable Staining Intensity Across Samples:

  • Cause: Inconsistent fixation or processing

  • Solution: Standardize fixation times and ensure consistent antigen retrieval conditions across all samples

• Poor Reproducibility:

  • Cause: Antibody batch variation or degradation

  • Solution: Aliquot antibodies upon receipt, store at recommended temperatures, and validate each new lot against known positive controls

Including appropriate positive controls (e.g., melanoma tissue samples with confirmed TICRR overexpression) and negative controls (primary antibody omission or isotype controls) is essential for accurate interpretation of IHC results .

How can researchers validate the specificity of anti-TICRR antibodies for their experimental system?

To ensure antibody specificity for TICRR, researchers should implement these validation strategies:

• TICRR Knockdown/Knockout Controls: Generate TICRR knockdown (via siRNA/shRNA) or knockout (via CRISPR-Cas9) cellular models and confirm signal reduction/absence with the antibody. Research has demonstrated successful TICRR knockdown validation using lentiviral-delivered shRNA in melanoma cell lines .

• Multiple Antibody Validation: Compare staining patterns using at least two different anti-TICRR antibodies targeting distinct epitopes to confirm concordant results.

• Peptide Competition Assay: Pre-incubate the antibody with excess immunizing peptide before application to samples; specific signals should be blocked.

• Western Blot Validation: Confirm a single band of appropriate molecular weight (~211 kDa for TICRR) in Western blot analysis.

• Recombinant Protein Controls: Use recombinant TICRR protein as a positive control and unrelated proteins as negative controls.

• Cross-species Reactivity Testing: If working with non-human models, test antibody specificity against the target species (the BosterBio A08002 antibody is predicted to react with mouse TICRR but requires validation) .

• Mass Spectrometry Validation: Perform immunoprecipitation followed by mass spectrometry to confirm capture of TICRR rather than non-specific proteins.

Thorough validation ensures experimental results truly reflect TICRR biology rather than antibody artifacts.

How should researchers interpret TICRR expression patterns in cancer studies?

When interpreting TICRR expression data in cancer research, consider these evidence-based guidelines:

Research has established that TICRR overexpression in cutaneous melanoma contributes nearly 60 points to the total risk score in prognostic nomograms, emphasizing its clinical significance beyond mere statistical correlation .

What are the key considerations when analyzing TICRR's relationship with immune infiltration?

When analyzing relationships between TICRR expression and immune infiltration, researchers should consider these methodological and interpretive approaches:

• Computational Deconvolution Methods:

  • Single-sample Gene Set Enrichment Analysis (ssGSEA) can quantify infiltration levels of 24 immune cell types in relation to TICRR expression

  • Research has identified significant correlations: positive with Th2 cells (r=0.283; P<0.001) and negative with pDCs (r=−0.293; P<0.001), Tregs (r=−0.275; P<0.001), cytotoxic cells (r=−0.263; P<0.001), DCs (r=−0.261; P<0.001), and neutrophils (r=−0.254; P<0.001)

• Co-expression Validation:

  • Verify computational findings with multiplex immunofluorescence, quantifying co-localization between TICRR and immune markers

  • Studies have confirmed high co-expression of TICRR with CD4 in melanoma tissues compared to normal skin

• Functional Context:

  • Consider the immunological implications of observed correlations

  • Negative correlation with cytotoxic T cells suggests potential immune evasion mechanisms

  • Positive correlation with Th2 cells may indicate skewing toward tumor-promoting immune responses

• Checkpoint Association Analysis:

  • Analyze relationships between TICRR and immune checkpoint molecules

  • TICRR shows associations with CD276 and other molecular targets relevant to melanoma immunotherapy

• Pathway Integration:

  • Consider how TICRR-related signaling pathways (PI3K/AKT/mTOR) may influence immune cell recruitment and function

  • Interpret immune infiltration patterns in the context of these signaling dynamics

These considerations facilitate meaningful interpretation of TICRR's potential role in modulating anti-tumor immunity and may provide insights into combination therapy approaches involving targeted and immune-based treatments.

How can TICRR knockdown and overexpression studies be effectively designed to elucidate functional roles?

To design robust TICRR functional studies using knockdown and overexpression approaches, researchers should implement these methodological strategies:

• Knockdown Strategy Selection:

  • Short-term studies: siRNA-mediated transient knockdown (48-72 hours)

  • Long-term studies: shRNA-mediated stable knockdown via lentiviral vectors

  • Research has successfully employed lentiviral shRNA targeting TICRR in melanoma cell lines, demonstrating efficient knockdown at the mRNA level

• Overexpression System Design:

  • Use lentiviral vectors carrying TICRR cDNA under a constitutive promoter for stable expression

  • Include epitope tags (FLAG, HA) for easy detection without relying solely on anti-TICRR antibodies

  • Consider inducible systems (Tet-On) to control expression timing and magnitude

• Essential Controls:

  • Empty vector controls for overexpression studies

  • Non-targeting shRNA/siRNA controls for knockdown studies

  • Rescue experiments with shRNA-resistant TICRR cDNA to confirm specificity

• Validation Requirements:

  • Confirm expression changes at both mRNA (qPCR) and protein (Western blot) levels

  • Quantify knockdown/overexpression efficiency (typically >70% knockdown considered effective)

• Functional Readouts:

  • Proliferation: CCK-8 assays, Ki67 immunofluorescence, flow cytometry cell cycle analysis

  • Migration: Scratch assays, transwell migration assays

  • Invasion: Matrigel-coated transwell invasion assays

  • Signaling pathway activity: Phospho-specific Western blotting for PI3K/AKT/mTOR components

• Rescue and Inhibitor Studies:

  • Combine TICRR overexpression with pathway inhibitors (e.g., LY294002 for PI3K/AKT) to demonstrate mechanistic dependence

  • Research has shown that LY294002 treatment partially reverses the proliferation, migration, and invasion-enhancing effects of TICRR overexpression in melanoma cells

These comprehensive experimental designs enable robust functional characterization of TICRR in cancer-related processes and help establish causal relationships between TICRR expression and observed phenotypes.

What are promising research areas for TICRR antibody applications in cancer immunotherapy studies?

Several innovative research directions utilizing TICRR antibodies could advance understanding of cancer immunotherapy:

• Dual Immunofluorescence Mapping of Immune Landscapes:

  • Apply anti-TICRR antibodies alongside immune checkpoint markers (PD-1, PD-L1, CTLA-4) to map spatial relationships between TICRR expression and immunosuppressive microenvironments

  • This could help predict immunotherapy responsiveness based on TICRR expression patterns

• TICRR as a Combinatorial Target:

  • Investigate whether TICRR inhibition could synergize with immune checkpoint blockade

  • Use antibodies to monitor changes in TICRR expression during immunotherapy response/resistance

• TICRR-mediated Immune Evasion Mechanisms:

  • Research has already established negative correlations between TICRR expression and cytotoxic T cell infiltration

  • Further studies could elucidate whether TICRR directly affects T cell activation or functions through indirect mechanisms

• Biomarker Development:

  • Develop standardized IHC protocols using anti-TICRR antibodies for potential clinical application

  • Validate TICRR as a predictive biomarker for immunotherapy response in prospective clinical trials

• Therapeutic Antibody Development:

  • Investigate the potential for developing therapeutic antibodies targeting extracellular or membrane-associated forms of TICRR if present

These research directions could significantly advance precision immunotherapy approaches, particularly in melanoma where TICRR overexpression has been clearly established .

How might researchers integrate TICRR analysis with current advances in single-cell technologies?

Integration of TICRR analysis with single-cell technologies offers several methodological opportunities:

• Single-cell Protein and RNA Co-detection:

  • Combine anti-TICRR antibodies with technologies like CITE-seq (Cellular Indexing of Transcriptomes and Epitopes by Sequencing) to simultaneously profile TICRR protein levels and transcriptome-wide expression

  • This would reveal cell-specific correlations between TICRR and gene expression programs

• Spatial Transcriptomics with Protein Overlay:

  • Apply anti-TICRR antibodies to tissue sections analyzed by spatial transcriptomics platforms (e.g., 10X Visium, GeoMx DSP)

  • This integration would map TICRR expression in relation to spatially resolved transcriptomes

• Single-cell Chromatin Accessibility and TICRR Binding:

  • Combine scATAC-seq with TICRR ChIP to identify cell-specific chromatin states associated with TICRR binding

  • This approach would reveal how TICRR's DNA replication regulatory function varies across heterogeneous cell populations

• Mass Cytometry Applications:

  • Develop anti-TICRR antibodies compatible with CyTOF (mass cytometry) for high-dimensional protein profiling

  • This would allow simultaneous measurement of TICRR with dozens of other proteins across thousands of single cells

• Live-cell Imaging of TICRR Dynamics:

  • Engineer fluorescently tagged nanobodies against TICRR for live-cell imaging of TICRR dynamics in real-time

  • This would provide insights into the temporal regulation of TICRR during cell cycle progression

These integrated approaches would address current knowledge gaps regarding cell-type specific functions of TICRR in heterogeneous tumor microenvironments and potentially reveal new therapeutic vulnerabilities.