FPGS3 Antibody

What is FPR3 and what is its significance in cancer research?

FPR3 (Formyl peptide receptor 3) is a G protein-coupled receptor with increasingly recognized implications in cancer progression. Recent pan-cancer analyses have revealed that FPR3 expression is upregulated in 25 different tumor types, including glioblastoma multiforme (GBM) and low-grade glioma (LGG) . The significance of FPR3 in cancer research lies in its correlation with adverse clinical outcomes and its association with immune cell infiltration. In numerous cancer types, heightened FPR3 expression has been found to correlate with poorer prognosis, immune checkpoint molecules, tumor mutation burden (TMB), and microsatellite instability (MSI) . These associations suggest that FPR3 may serve not only as a prognostic biomarker but also as a potential indicator for immunotherapy effectiveness.

How is FPR3 expressed in different cancer types?

FPR3 exhibits variable expression patterns across different malignancies. According to comprehensive pan-cancer analyses, FPR3 is upregulated in 25 tumor types, with particularly notable expression in gliomas . The protein has shown strong association with glioma compared to other cancer types. In both glioblastoma multiforme (GBM) and low-grade glioma (LGG), elevated FPR3 expression levels have been linked to worse prognosis . Immunohistochemistry and Western blot analyses have consistently confirmed upregulation of FPR3 protein expression in glioma specimens compared to adjacent non-tumor tissues . This differential expression pattern makes FPR3 a potentially valuable diagnostic marker for specific types of cancer, particularly within the central nervous system tumors.

What methods are recommended for detecting FPR3 in tissue samples?

For reliable detection of FPR3 in tissue samples, multiple complementary techniques should be employed. Immunohistochemistry (IHC) represents a primary method for visualizing FPR3 expression in patient specimens, as demonstrated in recent glioma studies . Western blot analysis provides quantitative confirmation of protein expression levels. For cell-specific expression analysis, flow cytometry using fluorescently labeled antibodies allows for accurate identification of FPR3-expressing cells . When conducting flow cytometry, it is advisable to employ dual antigen-specific labeling using two different fluorochromes (such as PE and AF647) to reduce background interference and increase specificity . This approach has been shown to achieve ≥99% positivity for target cells when properly optimized. Additionally, indirect immunofluorescence can be utilized to verify in-vitro binding capacity of FPR3 antibodies .

What is the relationship between FPR3 and immune cell infiltration in tumors?

FPR3 expression demonstrates significant associations with tumor-infiltrating lymphocytes (TILs) across various cancer types, with particularly strong correlations observed in gliomas . Analysis using the ESTIMATE algorithm has revealed that tumors with high FPR3 expression exhibit elevated immunological, stromal, and ESTIMATE scores compared to those with low expression . Specifically, FPR3 expression shows positive correlations with macrophage abundance, effector memory CD8 T cells, myeloid-derived suppressor cells, mast cells, and regulatory T cells in glioblastoma (correlation coefficients > 0.65, p < 0.05) . In high FPR3 expression groups, there are increased proportions of resting memory CD4 T cells, regulatory T cells, M0 and M1 macrophages, and neutrophils, whereas low FPR3 expression groups display higher proportions of naive B cells, plasma cells, and follicular helper T cells . This immunological profile suggests FPR3 may play a crucial role in shaping the tumor immune microenvironment.

How should researchers validate the specificity of FPR3 antibodies?

Validation of FPR3 antibody specificity requires a multi-step quality control process. Researchers should implement a standardized operating procedure including verification of purity, in-vitro binding capacity, and pathogenicity assessment . For purity verification, SDS-PAGE should be performed to confirm the antibody's molecular weight and homogeneity. Both direct and indirect immunofluorescence techniques should be employed to assess binding capacity to the target antigen . Flow cytometry offers a powerful method for verifying specificity, particularly when using dual fluorochrome labeling of the target antigen to identify true positive binding . To reduce background and false positives, comparison with an unrelated antibody or hybridoma cell line as a negative control is essential. Additionally, functional validation through ex-vivo pathogenicity assays, such as monolayer dissociation assays, can provide critical evidence of antibody functionality . Batch-to-batch consistency should be monitored by comparing variations in these parameters across different production runs.

What methodologies are recommended for studying FPR3's role in tumor cell proliferation and migration?

To investigate FPR3's functional role in tumor cell proliferation and migration, several validated methodologies can be employed. RNA interference techniques, particularly siRNA-mediated knockdown, have proven effective in reducing FPR3 expression in glioma cell lines such as U251 . Following knockdown verification by Western blot or qPCR, proliferation can be assessed using the CCK-8 (Cell Counting Kit-8) assay, which has demonstrated that FPR3 suppression significantly hinders glioblastoma cell proliferation compared to negative control cells . For migration studies, the wound healing assay represents a reliable approach, with results showing reduced migratory capacity of GBM cells following FPR3 knockdown . For more comprehensive assessment, researchers might consider complementing these assays with transwell migration and invasion assays, 3D spheroid growth models, or real-time cell analysis systems for continuous monitoring of cellular behavior. Additionally, in vivo xenograft models using FPR3-knockdown cells can provide insights into tumor growth dynamics in a physiologically relevant context.

How can researchers analyze the correlation between FPR3 expression and immune cell markers?

A comprehensive approach to analyzing correlations between FPR3 expression and immune cell markers involves integrating multiple analytical techniques. Researchers should begin with a correlation analysis between FPR3 expression and established gene markers for distinct immune cell populations. As demonstrated in previous studies, expression correlation coefficients (r values) and significance levels should be calculated for various immune cell markers . The table below shows correlation values from previous research:

For more detailed immune landscape characterization, researchers should employ computational methods such as CIBERSORT to estimate the relative fractions of immune cell types within tumor samples . Single-cell RNA sequencing data analysis can provide higher resolution insights into the specific immune cell subtypes associated with FPR3 expression. Additionally, multiplex immunohistochemistry or immunofluorescence staining of tissue sections for FPR3 alongside immune cell markers can visually confirm co-localization patterns and spatial relationships within the tumor microenvironment.

What are the recommended approaches for investigating FPR3's prognostic value in glioma?

To rigorously evaluate FPR3's prognostic value in glioma, researchers should implement a multi-faceted approach combining clinical data analysis with molecular profiling. Kaplan-Meier survival analysis stratifying patients based on FPR3 expression levels should be performed using data from established databases such as TCGA, CGGA, Rembrandt, and Gravendeel . Multivariate Cox regression analysis is essential to determine whether FPR3 represents an independent prognostic factor when accounting for established clinical variables (age, gender, tumor grade, IDH mutation status, and 1p/19q co-deletion status). For enhanced prognostic accuracy, researchers should consider developing a nomogram incorporating FPR3 expression with other significant clinical features . The performance of such prognostic models should be evaluated using concordance index (C-index), calibration plots, and time-dependent ROC curve analysis. Additionally, stratification of patients based on molecular subtypes (e.g., IDH-wildtype vs. IDH-mutant) can reveal subgroup-specific prognostic significance. Validation of findings across independent cohorts is crucial to establish robust prognostic utility.

How can FPR3 expression be correlated with therapeutic response in cancer patients?

Correlating FPR3 expression with therapeutic response requires systematic analysis of both retrospective and prospective clinical data. For conventional therapies, researchers should investigate the relationship between FPR3 expression levels and IC50 values of standard treatments. Previous research has shown that tumors with elevated FPR3 expression demonstrated significantly lower IC50 values for several therapeutics including Temozolomide, AMG-319, Bortezomib, Cediranib, Dasatinib, Entospletinib, Savolitinib, and 5-Fluorouracil compared to low-expression groups . Conversely, high-expression groups exhibited higher IC50 values for SB505124 and Vorinostat . For immunotherapy response prediction, researchers should analyze associations between FPR3 expression and established biomarkers such as tumor mutation burden (TMB) and microsatellite instability (MSI), as high correlations have been observed in several cancer types . Patient-derived xenograft (PDX) models with varying FPR3 expression levels can provide preclinical evidence of differential treatment responses. Ultimately, prospective clinical trials incorporating FPR3 expression analysis will be necessary to definitively establish its predictive value for specific therapeutic regimens.

What techniques are most effective for studying FPR3's mechanistic role in cancer pathogenesis?

Elucidating FPR3's mechanistic role in cancer pathogenesis requires integration of multiple advanced molecular biology techniques. Gene set enrichment analysis (GSEA) has previously identified multiple gene sets linked to FPR3 expression, including T-cell receptor signaling pathways, highlighting potential mechanistic connections to immune regulation . For pathway analysis, researchers should perform RNA-sequencing of FPR3-manipulated cancer cells (knockdown or overexpression) followed by differential expression analysis and pathway enrichment using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases . Chromatin immunoprecipitation sequencing (ChIP-seq) can reveal transcriptional regulatory mechanisms influenced by FPR3 signaling. For protein interaction studies, co-immunoprecipitation coupled with mass spectrometry can identify direct binding partners of FPR3. Phosphoproteomics analysis following FPR3 activation or inhibition can map downstream signaling cascades. Previous research has suggested FPR3 may inhibit the AKT/mTORC1 signaling pathway through modulation of cellular calcium ion fluxes in gastric cancer , providing a starting point for mechanistic investigation in other tumor types. CRISPR-Cas9-mediated genetic manipulation offers precise tools for creating cellular models with complete FPR3 knockout or specific domain mutations to dissect functional relationships.

What are common challenges in FPR3 antibody-based experiments and how can they be addressed?

When working with FPR3 antibodies, researchers frequently encounter several technical challenges that can impact experimental outcomes. One major issue is cross-reactivity with other formyl peptide receptors (FPR1 and FPR2) due to structural homology. To address this, researchers should validate antibody specificity using cells with confirmed FPR3 expression versus FPR3-knockout controls . Western blot analysis should demonstrate a single band of appropriate molecular weight, while immunohistochemistry should show expected cellular and subcellular localization patterns. Another common challenge is inconsistent batch-to-batch performance of antibodies. Implementation of standardized quality control procedures, including verification of purity and binding capacity for each batch, can mitigate this issue . For flow cytometry applications, dual-fluorochrome labeling techniques have been shown to reduce background and increase specificity, achieving ≥99% positivity for true target cells . In immunohistochemistry applications, optimizing antigen retrieval methods, blocking protocols, and antibody concentrations for each specific tissue type is essential. Finally, researchers should be aware that FPR3 expression can be modulated by experimental conditions, including cell culture density and inflammatory stimuli, potentially affecting experimental outcomes.

How should researchers design experiments to study FPR3's interaction with the tumor microenvironment?

Designing experiments to investigate FPR3's interactions with the tumor microenvironment requires a systems biology approach that captures the complex cellular and molecular networks involved. Co-culture systems represent a foundation for such studies, where FPR3-expressing tumor cells are cultured with various immune cell populations (macrophages, T cells, etc.) to assess reciprocal influences on migration, activation, and cytokine production. Three-dimensional organoid models incorporating multiple cell types can better recapitulate in vivo tumor architecture and cellular interactions. For in vivo studies, researchers should consider syngeneic mouse models with FPR3-manipulated tumor cells, allowing for assessment of immune infiltration and activation in an immunocompetent setting. Multiplex immunohistochemistry or immunofluorescence enables visualization of spatial relationships between FPR3-expressing cells and various immune cell subtypes within the tumor microenvironment . Single-cell RNA sequencing provides high-resolution transcriptional profiling to identify cell type-specific responses to FPR3 signaling. Finally, mass cytometry (CyTOF) with antibody panels targeting FPR3 alongside markers for various immune cell subsets and their activation states can provide detailed immune phenotyping at the single-cell level. These combined approaches allow for comprehensive assessment of FPR3's role in shaping tumor-immune interactions.

What quality control measures are essential when developing or selecting FPR3 antibodies for research?

Implementing rigorous quality control measures is crucial when developing or selecting FPR3 antibodies for research applications. A comprehensive quality control workflow should include verification of antibody purity, binding capacity, and functional activity . SDS-PAGE analysis under both reducing and non-reducing conditions should confirm antibody homogeneity and expected molecular weight. Size exclusion chromatography and mass spectrometry provide additional verification of antibody integrity and potential aggregation . Binding specificity should be assessed through multiple complementary methods, including ELISA, Western blot, immunohistochemistry, and flow cytometry, with appropriate positive and negative controls . Flow cytometric analysis using dual-fluorochrome labeling of the target antigen can achieve ≥99% specificity when properly optimized . For hybridoma-derived antibodies, verification of the producing cell line's specificity through CD138 and IgG gating combined with antigen-specific staining ensures continued production of the desired antibody . Batch-to-batch consistency should be monitored through comparative analysis of these parameters across different production runs. Finally, functional validation through biological assays relevant to the antibody's intended application, such as cell proliferation or migration assays for FPR3 functional studies, confirms that the antibody possesses the expected biological activity .

What are promising areas for future research on FPR3 as a therapeutic target in cancer?

Several promising research directions could advance the understanding of FPR3 as a therapeutic target in cancer. Development of specific FPR3 antagonists represents a priority area, given FPR3's association with tumor proliferation and migration . Initial screening could utilize small molecule libraries to identify compounds with high binding affinity and selectivity for FPR3 over other formyl peptide receptors. Structure-activity relationship studies would optimize lead compounds for improved pharmacokinetic properties. Another promising approach involves exploring combination therapies, as research has shown differential drug sensitivity correlations with FPR3 expression levels across multiple compounds . For example, tumors with elevated FPR3 expression demonstrated significantly lower IC50 values for Temozolomide and several kinase inhibitors, suggesting potential synergistic effects . Gene therapy approaches targeting FPR3 expression in tumors could build upon findings that FPR3 knockdown suppresses glioma cell proliferation and migration . Additionally, exploring FPR3's role in immunotherapy response represents a compelling direction, given its correlations with immune checkpoint molecules, tumor mutation burden, and microsatellite instability across multiple cancer types . Development of dual-targeting antibodies that simultaneously engage FPR3 and immune checkpoint molecules could potentially enhance anti-tumor immunity while directly targeting FPR3-expressing tumor cells.

How might FPR3 research connect with emerging concepts in tumor immunology?

FPR3 research intersects with several emerging concepts in tumor immunology, presenting opportunities for innovative investigation. The strong association between FPR3 expression and immune cell infiltration, particularly with regulatory T cells, M0 and M1 macrophages, and neutrophils in glioma , suggests its potential role in immune evasion mechanisms. Future research should explore how FPR3 signaling influences the polarization of tumor-associated macrophages between pro-inflammatory M1 and immunosuppressive M2 phenotypes, given the strong correlations observed with markers for both subtypes . The relationship between FPR3 and T cell receptor signaling pathways identified through gene set enrichment analysis warrants deeper investigation into how FPR3 might modulate T cell activation, exhaustion, or memory formation within the tumor microenvironment. Additionally, the correlation between FPR3 expression and microsatellite instability (MSI) in multiple cancers suggests a potential connection to neoantigen generation and presentation, which are critical determinants of immunotherapy response. Research integrating spatial transcriptomics with FPR3 expression analysis could provide insights into how FPR3-expressing cells interact with various immune populations within the complex tumor architecture, potentially revealing novel immunomodulatory mechanisms that could be therapeutically targeted.

What methodological advances would enhance future FPR3 research in cancer biology?

Advancement of FPR3 research in cancer biology would benefit from several methodological innovations. Development of more specific and sensitive FPR3 antibodies with reduced cross-reactivity to other formyl peptide receptors would enhance detection reliability across diverse applications. Standardized quality control procedures, similar to those implemented for other antibodies , would ensure consistent performance across studies. Creation of transgenic mouse models with conditional FPR3 knockout or overexpression in specific cell types would allow for detailed in vivo investigation of FPR3's tissue-specific functions in tumor development and progression. Single-cell multi-omics approaches combining transcriptomics, proteomics, and epigenomics would provide unprecedented resolution of FPR3-associated cellular states and signaling networks. Development of FPR3-specific small molecule probes compatible with imaging techniques would enable real-time visualization of FPR3 activity in living cells and tissues. High-throughput CRISPR screens focusing on genes that synthetically interact with FPR3 could identify novel therapeutic vulnerabilities in FPR3-expressing tumors. Implementation of artificial intelligence and machine learning algorithms to integrate multi-dimensional datasets (genomic, transcriptomic, proteomic, clinical) would accelerate the identification of FPR3-associated biomarkers and therapeutic targets. Finally, development of patient-derived organoid platforms incorporating FPR3 manipulation would provide more physiologically relevant models for preclinical evaluation of targeted therapeutics.

What is the current consensus on FPR3's role in cancer and its potential as a research target?

Current evidence strongly indicates that FPR3 plays a significant role in cancer biology, particularly in gliomas, where it has emerged as a promising research target. Pan-cancer analyses have demonstrated upregulation of FPR3 across 25 different tumor types, with particularly notable expression in glioblastoma multiforme (GBM) and low-grade glioma (LGG) . In these malignancies, elevated FPR3 expression correlates with worse clinical outcomes, suggesting its utility as a prognostic biomarker . Functional studies have established that FPR3 knockdown significantly impairs the proliferation and migration of glioma cells, providing direct evidence for its role in driving malignant phenotypes . The strong associations between FPR3 expression and immune cell infiltration patterns indicate its potential involvement in shaping the tumor immune microenvironment . Furthermore, correlations with immune checkpoint molecules, tumor mutation burden, and microsatellite instability across multiple cancer types suggest that FPR3 may serve as an indicator for immunotherapy effectiveness . Collectively, these findings position FPR3 as a valuable research target with potential applications in cancer diagnosis, prognosis, and therapeutic development. Future investigations focusing on FPR3-targeted approaches could yield significant advances in personalized cancer treatment strategies, particularly for glioma patients where conventional therapies often have limited efficacy.

How should researchers integrate FPR3 antibody studies into broader cancer research programs?

Researchers should strategically integrate FPR3 antibody studies into comprehensive cancer research programs through a multidisciplinary approach. Initially, baseline FPR3 expression profiling across diverse tumor types and patient cohorts using validated antibodies should establish the prevalence and clinical significance of FPR3 positivity . This foundation supports subsequent mechanistic investigations into how FPR3 contributes to cancer hallmarks like proliferation, migration, and immune evasion . Integration with genomic and transcriptomic profiling can identify molecular signatures associated with FPR3 expression, facilitating patient stratification for targeted therapies. Collaborative efforts between immunologists and cancer biologists should explore FPR3's immunomodulatory functions, given its strong correlations with various immune cell populations . Translational researchers can leverage FPR3 antibodies for developing novel diagnostics, such as immunohistochemistry panels that combine FPR3 with other prognostic markers. Drug discovery initiatives should incorporate FPR3 expression data when evaluating therapeutic responses, as differential drug sensitivities have been observed based on FPR3 levels . Clinical researchers should consider prospective trials stratifying patients by FPR3 expression to assess its predictive value for standard treatments and immunotherapies. Finally, rigorous quality control systems for FPR3 antibodies, similar to those described for other antibodies , should be implemented to ensure reliable and reproducible results across all research applications. This integrated approach will maximize the impact of FPR3 research on cancer diagnosis, prognosis, and treatment.