ICAM1 (Ab-512) Antibody

What is ICAM1 and why is it significant in research?

ICAM1 (CD54) is a transmembrane glycoprotein with 532 amino acid residues and a molecular weight of approximately 57.8 kDa in humans. It is primarily localized in the cell membrane and is notably expressed in various tissues including colon and endometrium. As a member of the ICAM protein family, it plays crucial roles in cell adhesion processes and regulation of apoptosis . ICAM1 has gained significant research interest due to its involvement in inflammatory responses, immune cell trafficking, and cancer progression. Recent studies have positioned ICAM1 as a potential therapeutic target for colorectal cancer and other malignancies, highlighting its importance in translational research .

What applications is ICAM1 (Ab-512) Antibody suitable for?

ICAM1 (Ab-512) Antibody can be utilized across multiple experimental platforms including:

• Western Blot (WB): Detects ICAM1 protein in cell and tissue lysates, providing information about expression levels and molecular weight

• Flow Cytometry (FCM): Enables quantification and characterization of ICAM1-expressing cell populations

• Immunohistochemistry (IHC): Visualizes ICAM1 distribution in tissue sections, particularly useful for studying expression patterns in normal versus pathological samples

• Immunoprecipitation (IP): Allows isolation of ICAM1 and its binding partners for further analysis

The antibody has demonstrated consistent performance across these applications when proper optimization is conducted. For Western blot applications, it typically detects a band at approximately 57-60 kDa depending on the glycosylation status of ICAM1 .

How should researchers select between various ICAM1 antibodies for their experiments?

Selection criteria should include:

• Epitope specificity: Whether the antibody recognizes the extracellular domain, transmembrane region, or cytoplasmic tail of ICAM1

• Species reactivity: While many antibodies recognize human ICAM1, cross-reactivity with mouse, rat, or other species varies considerably

• Clonality: Monoclonal antibodies offer high specificity for a single epitope, while polyclonal antibodies may provide higher sensitivity by recognizing multiple epitopes

• Validation data: Consider antibodies with published validation in applications similar to your intended use

• Post-translational modification sensitivity: Some antibodies may have differential recognition of glycosylated or phosphorylated forms of ICAM1

What are the known synonyms and orthologs of ICAM1?

Understanding ICAM1 nomenclature is essential when designing experiments and interpreting literature:

• Common synonyms: CD54, P3.58, cell surface glycoprotein P3.58, epididymis secretory sperm binding protein, human rhinovirus receptor, and BB2

• Species orthologs: ICAM1 gene orthologs have been reported in mouse, rat, zebrafish, and chimpanzee, allowing for comparative studies across model organisms

Researchers should be aware that antibody cross-reactivity with orthologs must be experimentally verified rather than assumed.

How does ICAM1 function in cancer progression through the c-MET-SRC signaling axis?

Recent studies have revealed a sophisticated signaling mechanism whereby ICAM1 promotes cancer progression:

• ICAM1 undergoes phosphorylation by tyrosine-protein kinase Met (c-MET)

• Phosphorylated ICAM1 interacts with SRC, increasing SRC kinase activity

• Activated SRC further accelerates downstream signaling pathways

• This cascade promotes malignant phenotypes including metastasis and angiogenesis

This mechanism positions ICAM1 as an adapter protein mediating the c-MET-SRC signaling axis. Importantly, treatment with antibodies targeting ICAM1 has demonstrated therapeutic effects in reducing metastasis and angiogenesis in experimental models . When investigating this pathway, researchers should consider using phospho-specific antibodies alongside total ICAM1 antibodies to distinguish between phosphorylated and non-phosphorylated forms.

What experimental designs are optimal for studying ICAM1's role in epithelial-mesenchymal transition (EMT)?

Based on current literature, the following experimental approaches are recommended:

• Loss-of-function studies:

  • ICAM1 knockdown using siRNA or shRNA in cancer cell lines has been shown to reduce the expression of EMT markers and regulators including N-Cadherin, Vimentin, Snail, and Slug

  • These should be validated through qRT-PCR and western blotting

• Gain-of-function studies:

  • Overexpression of ICAM1 in relevant cell models (e.g., HT-29 for colorectal cancer) has demonstrated increased cell migration and invasion, with concurrent upregulation of EMT markers

• In vivo metastasis models:

  • Orthotopic mouse models where ICAM1-manipulated cells are injected into the cecal wall have provided valuable insights into metastatic potential

  • Analysis should include qRT-PCR, immunohistochemistry, and immunofluorescence staining to assess EMT markers in the resulting tumors

• Co-expression analysis:

  • Cancer Genome Atlas (TCGA) database analysis can determine correlations between ICAM1 expression and EMT markers in patient samples

How can ICAM1 (Ab-512) Antibody be used to investigate the relationship between ICAM1 and tumor angiogenesis?

Investigation of ICAM1's role in angiogenesis can be approached through:

• Immunohistochemical analysis of tumor vasculature:

  • Double staining with ICAM1 antibody and endothelial markers (CD31, CD34)

  • Quantification of microvascular density in ICAM1-high versus ICAM1-low regions

• In vitro tube formation assays:

  • Treatment of endothelial cells with conditioned media from ICAM1-overexpressing or ICAM1-silenced cancer cells

  • Analysis of tube formation capacity and expression of angiogenesis-related markers

• Analysis of angiogenic factors:

  • qRT-PCR and ELISA assessment of angiogenesis-related growth factors in ICAM1-manipulated cancer cells

  • Correlation studies between ICAM1 expression and angiogenic factors in patient samples

What methodologies can detect ICAM1 phosphorylation status when studying the c-MET-SRC pathway?

Investigating ICAM1 phosphorylation requires specialized approaches:

• Immunoprecipitation followed by phospho-tyrosine detection:

  • Immunoprecipitate ICAM1 using ICAM1 (Ab-512) Antibody

  • Probe with anti-phosphotyrosine antibodies to detect phosphorylation

• Phospho-specific antibodies:

  • Use site-specific phospho-antibodies if available (targeting known c-MET phosphorylation sites)

• Mass spectrometry:

  • Immunoprecipitate ICAM1 and perform mass spectrometric analysis to identify and quantify phosphorylation sites

• Proximity ligation assay:

  • Detect protein-protein interactions between ICAM1 and SRC or c-MET in situ

  • Visualize interactions in fixed cells or tissue sections

What is the optimal protocol for immunohistochemistry using ICAM1 antibodies?

For successful IHC staining of ICAM1 in tissue sections, follow these methodological guidelines:

• Tissue preparation:

  • Use formalin-fixed, paraffin-embedded (FFPE) sections (5-7 μm thickness)

  • Fresh frozen sections may provide superior antigen preservation but require different fixation protocols

• Antigen retrieval:

  • Heat-induced epitope retrieval in citrate buffer (pH 6.0) or EDTA buffer (pH 9.0)

  • Optimize time and temperature (typically 95-100°C for 20-30 minutes)

• Blocking and antibody incubation:

  • Block endogenous peroxidase activity with 3% H₂O₂

  • Use 5-10% normal serum from the same species as the secondary antibody

  • Incubate with primary antibody overnight at 4°C at optimized dilution (typically 1:100 - 1:500)

  • Wash thoroughly and incubate with appropriate secondary antibody

• Detection and counterstaining:

  • Develop signal using DAB or other chromogens

  • Counterstain with hematoxylin

  • Mount with appropriate mounting medium

• Controls:

  • Include positive control tissue known to express ICAM1 (endothelial cells, inflamed tissues)

  • Include negative controls by omitting primary antibody

  • Consider using ICAM1-knockdown tissues as specificity controls

How should ICAM1 antibodies be validated for specificity in Western blot applications?

Rigorous validation of antibody specificity is crucial for reliable Western blot results:

• Positive and negative controls:

  • Use cell lines with known ICAM1 expression as positive controls

  • Include ICAM1-knockout or knockdown samples as negative controls

• Blocking peptide competition:

  • Pre-incubate antibody with excess immunizing peptide

  • Compare signal with and without peptide competition

• Multiple antibody validation:

  • Confirm results with a second antibody targeting a different epitope

  • Compare monoclonal and polyclonal antibody staining patterns

• Expected molecular weight verification:

  • ICAM1 typically appears at approximately 57.8 kDa, but glycosylation can increase apparent molecular weight

  • Validate with recombinant ICAM1 protein of known molecular weight

• Cross-species reactivity:

  • If working with non-human samples, verify cross-reactivity with the target species

  • ICAM1 orthologs exist in mouse, rat, zebrafish, and chimpanzee, but sequence differences may affect antibody binding

What are the recommended protocols for flow cytometry using ICAM1 antibodies?

For optimal flow cytometry results when analyzing ICAM1 expression:

• Cell preparation:

  • Use single-cell suspensions (1×10⁶ cells per sample)

  • Ensure viability >90% for best results

  • If analyzing tissue samples, optimize digestion protocols to preserve surface epitopes

• Staining protocol:

  • Wash cells in PBS containing 1-2% BSA or FBS

  • Block Fc receptors to prevent non-specific binding

  • Incubate with primary antibody (or directly conjugated antibody) at optimized concentration

  • For indirect staining, incubate with fluorophore-conjugated secondary antibody

  • Include viability dye to exclude dead cells

• Controls and compensation:

  • Include unstained, isotype, and fluorescence-minus-one (FMO) controls

  • For multicolor panels, proper compensation is essential

  • Consider using cells with known high and low ICAM1 expression as biological controls

• Analysis considerations:

  • ICAM1 expression can be heterogeneous in cell populations

  • Consider analyzing median fluorescence intensity (MFI) rather than just percent positive

What are common issues when using ICAM1 antibodies in Western blot, and how can they be resolved?

How can researchers optimize experiments investigating ICAM1's role in the SRC signaling pathway?

Based on current research findings, these methodological approaches are recommended:

• Kinase activity assays:

  • Perform in vitro SRC kinase assays to assess the direct effect of ICAM1 manipulation on SRC activity

  • Compare results between ICAM1-knockdown, overexpression, and control conditions

• Phosphorylation status analysis:

  • Monitor phosphorylation levels of SRC and downstream targets like STAT3

  • Use inhibitors of the pathway to establish causality (SRC inhibitors, STAT3 inhibitors)

• Functional assays:

  • Couple biochemical analyses with functional readouts such as cell migration, invasion, and tube formation assays

  • Determine whether the malignant phenotypes induced by ICAM1 can be mitigated by inhibiting pathway components

• Correlation studies in patient samples:

  • Analyze correlation between ICAM1 expression and SRC activity signatures in patient databases

  • Perform Gene Set Enrichment Analysis (GSEA) to identify pathway associations

What controls should be included when using ICAM1 antibodies in research?

Rigorous experimental design requires appropriate controls:

• Positive controls:

  • Cell lines with known high ICAM1 expression (e.g., activated endothelial cells)

  • Recombinant ICAM1 protein for Western blot

  • Tissues with confirmed ICAM1 expression for IHC (e.g., inflamed tissues)

• Negative controls:

  • ICAM1 knockout or knockdown samples

  • Cell lines with naturally low ICAM1 expression

  • Secondary antibody-only controls to detect non-specific binding

• Specificity controls:

  • Peptide competition assays

  • Comparison with alternative antibodies targeting different epitopes

  • Isotype controls for flow cytometry

• Experimental validation controls:

  • When studying ICAM1 in cancer, include parallel experiments with antibody treatment to validate functional relevance

  • For phosphorylation studies, include phosphatase treatment controls