IKBIP negatively regulates NF-κB activation by inhibiting phosphorylation of IKKα/β kinases, thereby disrupting IKK complex formation . This suppression reduces proinflammatory cytokine production and modulates immune responses .
Key Mechanisms:
NF-κB Signaling Inhibition: Binds IKKα/β, blocking IκBα phosphorylation and subsequent NF-κB nuclear translocation .
Apoptosis Promotion: Acts as a p53 target, enhancing apoptosis in vascular endothelial cells .
Immune Modulation: Correlates with immune cell infiltration (e.g., T cells, macrophages) in cancers, influencing tumor microenvironment (TME) dynamics .
Recombinant IKBIP is critical for validating antibodies, studying protein interactions, and investigating NF-κB pathways.
IKBIP’s expression is linked to cancer prognosis, immune regulation, and drug responses:
Positive TME Association: High stromal/immune scores in COAD, BLCA, and GBM .
Drug Sensitivity: Linked to response to simvastatin and resistance to paclitaxel .
Immune Infiltration: IKBIP expression correlates with Th2 cells and CLP (common lymphoid progenitor) infiltration in cancers .
Diagnostic Potential: Acts as a biomarker for pan-cancer prognosis but requires validation in BRCA, PAAD, and THYM .
Therapeutic Targeting: Emerging strategies focus on disrupting IKBIP-IKK interactions to modulate inflammation .
IKBIP (Inhibitor of nuclear factor kappa-B kinase-interacting protein) is a gene that has received minimal attention from researchers until recently. It has been identified as one of the target genes of p53, suggesting a potential role in tumor suppression pathways .
The protein encoded by this gene functions within the NF-κB signaling cascade, which regulates various cellular processes including immunity, inflammation, and cell survival. IKBIP has been found to be highly expressed in most cancers and appears to play a crucial role in both carcinogenesis and cancer immunity .
Methodologically, when studying IKBIP's basic function, researchers should consider:
Performing gene expression analysis across normal human tissues using publicly available databases like Human Proteome Atlas (HPA)
Conducting knockdown/knockout studies to observe phenotypic changes
Investigating protein-protein interactions, particularly with other components of the NF-κB pathway
Examining transcriptional regulation, especially in relation to p53-mediated pathways
IKBIP interacts with the inhibitory-κB kinase (IKK) complex, which is a central regulator of the NF-κB signaling pathway. The NF-κB pathway exists in canonical and non-canonical forms, with IKKα being a key regulator of the non-canonical pathway .
The non-canonical NF-κB pathway is typically activated by members of the TNF superfamily, including lymphotoxin-β (LT-β), TNFSF14 (LIGHT), TWEAK, CD40L, RANKL, and BAFF . IKBIP's interaction with this pathway appears to influence immune cell infiltration and tumor microenvironment composition.
When investigating this relationship, researchers should:
Study the physical interaction between IKBIP and IKK components using co-immunoprecipitation
Analyze the impact of IKBIP expression on downstream NF-κB target genes
Examine pathway activation using phospho-specific antibodies for key pathway components
Consider the temporal dynamics of pathway activation in response to specific stimuli
Several databases provide valuable resources for IKBIP research:
TIMER database (https://cistrome.shinyapps.io/timer/) - Examines IKBIP expression profiles and immune infiltrates in pan-cancer
TCGA - Contains expression data for 33 tumor types, TMB data, MSI data, and clinical data, accessible through the UCSC Xena online database (https://xenabrowser.net/)[1]
UALCAN (http://ualcan.path.uab.edu/index.html) - Provides proteomics information from the CPTAC database
cBioPortal (https://www.cbioportal.org/) - Offers data on methylation modification and genetic changes in tumor tissues
Human Proteome Atlas (HPA) (https://www.proteinatlas.org/) - Provides immunohistochemistry images showing protein distribution in human tissues and cells
For miRNA studies related to IKBIP, researchers can utilize:
DIANA-microT (http://diana.imis.athena-innovation.gr/DianaTools/index.php?r=microT_CDS/index)
miRDB (http://mirdb.org/miRDB/)
miRWalk (http://mirwalk.umm.uni-heidelberg.de/)
TargetScan
IKBIP has emerged as a promising pan-cancer biomarker based on comprehensive multi-database analyses. Research shows that IKBIP is highly expressed in most cancer types and its expression correlates with patient prognosis in several major cancers .
To evaluate IKBIP as a pan-cancer biomarker, researchers should:
IKBIP expression shows significant correlation with tumor-infiltrating immune cells across multiple cancer types. Analysis using the TIMER database revealed substantial correlations between IKBIP expression and:
B cells in 12 cancer types
CD4+ T cells in 13 cancer types
CD8+ T cells in 23 cancer types
Macrophages in 23 cancer types
Neutrophils in 24 cancer types
To study this relationship, researchers should:
Use computational tools like TIMER, xCell, or CIBERSORT to estimate immune cell infiltration
Perform correlation analysis between IKBIP expression and immune cell abundance
Validate computational findings with immunohistochemistry or flow cytometry
Investigate the functional impact using co-culture experiments or immune cell depletion models
The relationship between IKBIP and immune cells varies by cancer type. For example, IKBIP expression in COAD, LGG, BLCA, PRAD, STAD, BRCA, and READ was negatively correlated with various immune cell subtypes, while it was positively correlated in THYM, OV, and LAML tissues .
IKBIP expression shows significant correlations with both TMB and MSI across multiple cancer types:
TMB Correlations:
IKBIP expression positively correlates with TMB in 13 cancer types
This suggests a potential relationship between IKBIP and genomic instability
MSI Correlations:
IKBIP expression positively correlates with MSI levels in ACC, COAD, READ, and UCEC
IKBIP expression negatively correlates with MSI levels in CHOL, LGG, LUAD, and LUSC
To investigate these relationships, researchers should:
Calculate TMB using Perl scripts to count somatic mutations, normalized by dividing with exon length
Extract MSI scores from TCGA database
Use the "cor.test" command with Spearman's method to examine correlations between IKBIP expression and TMB/MSI
Generate radar plots using the "fmsb" R package to visualize relationships
Validate findings through experimental models with engineered TMB/MSI status
These correlations suggest that IKBIP may play a role in response to immunotherapy, as both TMB and MSI are established biomarkers for immunotherapy efficacy.
Based on current research approaches, the following methodological framework is recommended:
Bioinformatic Analysis:
Multi-database analysis (TCGA, TIMER, UALCAN, CPTAC, CBIoportAL)
Expression analysis across 33 tumor types using log2 TPM measurements
Survival analysis using Kaplan-Meier and Cox regression with R packages "survminer" and "survival"
Clinical correlation analysis using "ggpubr" and "limma" R packages
Immune Analysis:
Immune infiltration analysis using TIMER and xCell
Correlation analysis with immune checkpoint genes
ESTIMATE approach to analyze stromal and immune scores
Analysis of correlation with five types of immune pathways (chemokine, receptor, MHC, immuno-inhibitory, and immunostimulatory)
Functional Analysis:
Gene Set Enrichment Analysis (GSEA) using GO and KEGG databases
Pathway analysis using R packages "limma," "org.Hs.eg.db," "clusterProfiler," and "enrichplot"
ceRNA network construction using Cytoscape to analyze mRNA, miRNA, and ncRNA interactions
Experimental Validation:
Immunohistochemistry to validate protein expression patterns
In vitro functional assays to assess impact on proliferation, migration, and invasion
In vivo models to evaluate impact on tumor growth and immune infiltration
IKBIP has potential as a therapeutic target based on its role in carcinogenesis and cancer immunity. Several approaches could be considered:
Direct targeting of IKBIP: Development of small molecule inhibitors or antibodies against IKBIP
Upstream targeting: Modulating the p53 pathway to influence IKBIP expression
NF-κB pathway intervention: Using existing IKK inhibitors like BMS-345541, which is a highly selective inhibitor of IκB kinase that binds at an allosteric site of the enzyme and blocks NF-κB-dependent transcription
Immunotherapy combination: Targeting IKBIP in conjunction with immune checkpoint inhibitors
When designing experiments to validate IKBIP as a therapeutic target, researchers should:
Perform knockdown/knockout studies to assess impact on cancer cell phenotypes
Test combination approaches with existing therapies
Evaluate effects on immune infiltration and the tumor microenvironment
Conduct patient stratification analysis to identify which patients might benefit most
IKBIP expression shows significant correlations with both stromal and immune components of the TME. Using the ESTIMATE approach, research has shown:
Stromal Score Correlations:
IKBIP expression positively correlates with stromal scores in PAAD, BRCA, COAD, READ, ESCA, and BLCA
Immune Score Correlations:
IKBIP expression positively correlates with immune scores in COAD, BLCA, GBM, PAAD, and PRAD
IKBIP expression negatively correlates with immune scores in THYM
To investigate this relationship, researchers should:
Use the ESTIMATE algorithm to calculate stromal and immune scores
Perform correlation analysis between IKBIP expression and these scores
Validate findings using spatial transcriptomics or multiplexed immunohistochemistry
Conduct co-culture experiments with stromal cells and immune cells to assess functional interactions
These findings suggest that elevated IKBIP expression may create an immunosuppressive environment in certain cancer types, which has important implications for immunotherapy strategies.
Several challenges must be addressed to translate IKBIP research into clinical applications:
To address these challenges, researchers should:
Conduct multi-center validation studies
Develop reliable biomarker assays for clinical use
Investigate mechanisms of action through functional studies
Identify patient subgroups most likely to benefit from IKBIP-targeted approaches
Future research on IKBIP would benefit from:
Single-cell RNA sequencing: To understand IKBIP expression heterogeneity within tumors and across cell types
CRISPR-Cas9 screening: To identify synthetic lethal interactions with IKBIP
Patient-derived organoids: To test IKBIP-targeted therapies in more physiologically relevant models
Systems biology approaches: To integrate IKBIP into broader signaling networks
Structural biology studies: To determine the three-dimensional structure of IKBIP and design targeted inhibitors
A comprehensive multi-omics approach would include:
Genomics: Analysis of mutations, copy number variations, and structural variations affecting IKBIP
Transcriptomics: RNA-seq to evaluate expression levels across cancer types and conditions
Proteomics: Mass spectrometry to identify IKBIP protein interactions and post-translational modifications
Epigenomics: Analysis of DNA methylation, histone modifications, and chromatin accessibility at the IKBIP locus
Metabolomics: Investigation of metabolic changes associated with IKBIP expression
Integration: Using computational methods to integrate these data types and identify patterns
Researchers should employ advanced bioinformatic tools for integration, including network analysis, machine learning approaches, and causal inference methods.