eIF3m is a non-core subunit of the eIF3 complex, which facilitates mRNA recruitment to the 43S pre-initiation complex and regulates translation of oncogenic and proliferation-related mRNAs . It stabilizes the eIF3 complex by interacting with subunits eIF3f and eIF3h, ensuring structural integrity and translation initiation . Dysregulation of eIF3m is linked to tumorigenesis, including colon, breast, and lung cancers .
eIF3m antibodies have been pivotal in elucidating its oncogenic roles:
Triple-Negative Breast Cancer (TNBC): Knockdown of eIF3m reduced cell proliferation, migration, and invasion while increasing apoptosis in MDA-MB-231 and MDA-MB-436 cells. It regulates CDC25A (cell cycle progression) and EMT-related proteins .
Lung Adenocarcinoma (LADC): Overexpression of eIF3m enhanced tumor growth in vivo, while knockdown suppressed proliferation and induced apoptosis. It upregulates CAPRIN1, an oncogene driving malignant phenotypes .
Colon Adenocarcinoma: High eIF3m expression correlates with larger tumor size, advanced Dukes’ stage, and poor prognosis. Serum eIF3m levels in patients were significantly elevated compared to healthy controls .
eIF3m promotes cancer progression via:
eIF3m forms subcomplexes with eIF3f and eIF3h, stabilizing the eIF3 complex. This interaction is critical for:
Ribosomal Recruitment: Ensuring proper assembly of the 43S pre-initiation complex .
mRNA Scanning: Enabling translation of specific mRNAs with structured 5’ untranslated regions (UTRs) .
Serum Detection: Elevated eIF3m levels in colon cancer patients suggest utility as a non-invasive biomarker .
Tissue-Specific Expression: Cytoplasmic staining in tumors versus normal tissues highlights its tumor-specific role .
Therapeutic Targeting: While eIF3m is implicated in carcinogenesis, specific inhibitors remain under development .
Cross-Reactivity: Polyclonal antibodies may require validation for off-target binding, particularly in species-specific studies .
Mechanistic Gaps: Further studies are needed to explore eIF3m’s role in other cancers (e.g., hepatocellular carcinoma) and its interaction with viral proteins .
EIF3m antibody has been extensively validated across multiple experimental applications in cancer research, particularly in studies involving human cancer cell lines and tissues. The antibody demonstrates high specificity for detection of eIF3m (molecular weight 35-43 kDa) in multiple applications including:
Western Blot (WB): Effective at dilutions of 1:500-1:3000
Immunoprecipitation (IP): 0.5-4.0 μg for 1.0-3.0 mg of total protein lysate
Immunohistochemistry (IHC): 1:20-1:200
For optimal results, the antibody has been positively tested in multiple cell lines including HeLa, HepG2, MCF-7, and in mouse and rat brain tissues. When conducting IHC experiments, antigen retrieval with TE buffer pH 9.0 is recommended, though citrate buffer pH 6.0 may serve as an alternative .
When designing experiments with eIF3m antibody, implement the following control strategies:
Positive controls: Include samples known to express eIF3m such as HeLa cells, HepG2 cells, MCF-7 cells, or brain tissue samples from mice or rats .
Negative controls:
Tissue samples from eIF3m knockout models
Primary antibody omission control
Isotype control (rabbit IgG at equivalent concentration)
Loading controls: When performing Western blot, include appropriate housekeeping proteins to normalize expression levels across samples.
Experimental validation should include antibody titration to determine optimal working concentration for your specific experimental system .
For optimal Western blot results with eIF3m antibody:
Lysate preparation:
Extract proteins using RIPA buffer containing protease inhibitors
For cell lines: Harvest cells at 70-80% confluence
For tissue samples: Homogenize in cold RIPA buffer (3-5 mL/g tissue)
Centrifuge at 14,000g for 15 minutes at 4°C
Collect supernatant and determine protein concentration
SDS-PAGE conditions:
Load 20-40 μg protein per lane
Use 10-12% polyacrylamide gels for optimal separation of 35-43 kDa eIF3m protein
Transfer to PVDF membrane at 100V for 60-90 minutes
Immunoblotting protocol:
This methodology has been validated in multiple cancer cell lines including LADC cell lines NCI-H1975 and NCI-H1395 .
To investigate eIF3m's role in translational regulation and cancer progression, implement the following comprehensive methodological approach:
RNA immunoprecipitation (RIP) assay:
Crosslink cells with formaldehyde to preserve RNA-protein interactions
Lyse cells and fragment chromatin
Immunoprecipitate with eIF3m antibody (3-5 μg)
Isolate bound RNA and perform RT-PCR to identify bound transcripts
Include primers targeting the 5'UTR regions of candidate genes (e.g., CAPRIN1, TRAF6, NUP160, PDHX)
This approach has confirmed that eIF3m specifically binds to the 5'UTR of CAPRIN1
RNA pull-down assay:
Functional validation:
These methodologies have revealed that eIF3m promotes malignant phenotypes in lung adenocarcinoma through translational regulation of oncogenic factors like CAPRIN1 .
When encountering conflicting eIF3m antibody results across different cancer cell lines, implement the following systematic troubleshooting approach:
Cancer-type specific expression profiling:
The cancer-promoting mechanism of eIF3m varies across cancer types
Analyze TCGA datasets using tools like UALCAN (http://ualcan.path.uab.edu) and GEPIA (http://gepia.cancer-pku.cn)
Generate expression profiles and Kaplan-Meier survival plots to understand cancer-specific patterns
Analysis of post-translational modifications:
Investigate cancer-specific post-translational modifications that might affect antibody binding
Examine interaction with deubiquitinases like UCHL5 that stabilize eIF3m
Implement co-immunoprecipitation with UCHL5 antibody followed by eIF3m detection
Use UCHL5 knockdown (shRNA sequence: 5'-GCAAAGAAAGCTCAGGAAACC-3') to assess effects on eIF3m stability
Multiple antibody validation approach:
Compare results using different antibody clones targeting distinct epitopes
Include both N-terminal and C-terminal targeting antibodies
Validate antibody specificity using eIF3m-knockout controls for each cell line
Target gene expression correlation:
This comprehensive validation approach has revealed that eIF3m's effects on oncogenic gene expression differ between cancer types, explaining potentially conflicting experimental results .
For optimal dual immunofluorescence staining with eIF3m antibody and other translation initiation factors:
Protocol optimization:
Primary antibody combinations: Use rabbit polyclonal anti-eIF3m (1:200-1:800) with mouse monoclonal antibodies against other translation factors
Sequential antibody incubation: Apply antibodies sequentially rather than simultaneously to prevent cross-reactivity
Buffer optimization: Use TBS with 0.025% Triton X-100 for all wash steps
Signal amplification: Consider tyramide signal amplification for detecting low abundance proteins
Cross-reactivity prevention:
Perform single-antibody controls alongside dual staining
Include adsorption controls (pre-incubating antibody with recombinant protein)
Use highly cross-adsorbed secondary antibodies
Implement spectral unmixing if using fluorophores with overlapping emission spectra
Validated cell models:
This approach enables visualization of co-localization patterns between eIF3m and other translation factors at subcellular resolution, providing insights into translation initiation complex formation in different cellular contexts.
To investigate relationships between eIF3m and oncogenic signaling pathways:
Integrative experimental design:
Compare expression levels of eIF3m with established oncogenic markers
Implement pathway inhibitors to assess effects on eIF3m expression
Perform gain/loss-of-function studies followed by pathway activation assays
mRNA target identification:
Protein-protein interaction analysis:
Functional validation in animal models:
This comprehensive approach has revealed that eIF3m promotes LADC growth, invasion, and metastasis through specific oncogenic pathways involving CAPRIN1 upregulation .
For rigorous assessment of eIF3m antibody specificity across cancer tissue samples:
Comprehensive validation panel:
Multimodal analytical approach:
IHC optimization: Test antigen retrieval methods (TE buffer pH 9.0 vs. citrate buffer pH 6.0)
Antibody titration: Test dilution range (1:20-1:200) for optimal signal-to-noise ratio
Competitive binding assays: Pre-incubate antibody with recombinant eIF3m protein
Western blot correlation: Compare IHC results with Western blot data from the same samples
Cancer-type specific validation:
This systematic approach ensures reliable detection of eIF3m across diverse tissue types, facilitating accurate assessment of its role in different cancer contexts.
To comprehensively evaluate eIF3m antibody performance across subcellular compartments:
Subcellular fractionation analysis:
High-resolution immunofluorescence microscopy:
Stimulus-dependent localization:
Examine eIF3m localization under:
Normal growth conditions
Translation inhibition (cycloheximide, puromycin)
Stress conditions (arsenite, thapsigargin)
Growth factor stimulation
Quantify redistribution kinetics
This multimodal approach reveals that while eIF3m primarily associates with cytoplasmic translation complexes, its subcellular distribution may change under specific cellular conditions, potentially reflecting different functional states in cancer progression.
For optimal immunohistochemistry results with eIF3m antibody in FFPE tissues:
Tissue preparation and fixation:
Fix tissues in 10% neutral buffered formalin for 24-48 hours
Process and embed in paraffin following standard protocols
Cut sections at 4-6 μm thickness
Mount on positively charged slides
Antigen retrieval optimization:
Antibody conditions:
Validation in cancer tissues:
Following these parameters ensures reliable detection of eIF3m in FFPE tissue sections, facilitating accurate assessment of its expression in cancer pathology studies.
For developing robust multiplexed flow cytometry with eIF3m antibody:
Sample preparation optimization:
Cell fixation: 4% paraformaldehyde (10 minutes, room temperature)
Permeabilization: 0.1% Triton X-100 or saponin-based buffers
Blocking: 5% normal serum (match to secondary antibody species)
Single-cell suspension: Filter through 40-70 μm cell strainer
Antibody panel design:
eIF3m antibody conjugation: Consider custom fluorophore conjugation (e.g., Alexa Fluor 488)
Alternative: Use unconjugated primary (1:200-1:800) followed by fluorescent secondary
Compatible markers:
Cell cycle proteins (Ki67, cyclins)
Translation factors (other eIF3 subunits)
Cancer stem cell markers (CD44, CD133)
Controls and validation:
Fluorescence minus one (FMO) controls
Isotype controls (rabbit IgG)
Knockdown validation (using validated shRNAs)
Compensation controls for multicolor analysis
Gating strategy:
Initial gating: FSC/SSC for viable cells
Singlet selection: FSC-H vs FSC-A
Negative population definition: Based on isotype control
eIF3m expression levels: Low, medium, high based on fluorescence intensity
This approach enables quantitative analysis of eIF3m expression at the single-cell level, facilitating correlation with other cancer-related markers and cell states.
To address non-specific binding in co-immunoprecipitation with eIF3m antibody:
Lysis buffer optimization:
Test multiple lysis conditions:
RIPA buffer (stringent, may disrupt weak interactions)
NP-40 buffer (mild, preserves protein complexes)
Digitonin buffer (gentle, maintains membrane complexes)
Add detergent modifiers: 0.1-0.5% deoxycholate to reduce non-specific binding
Include protease and phosphatase inhibitors
Pre-clearing protocol:
Pre-clear lysate with protein A/G beads (1 hour at 4°C)
Include isotype control antibody pre-clearing step
Implement dual pre-clearing for high-background samples
Antibody incubation conditions:
Washing optimization:
Implement stringency gradient washing:
First wash: Low stringency (buffer with normal salt)
Middle washes: Medium stringency (increased salt)
Final wash: Low stringency (return to normal conditions)
Maintain cold temperature (4°C) throughout
Use gentle inversion rather than vortexing
This methodical approach has successfully identified specific eIF3m interactions, including UCHL5, a deubiquitinase that regulates eIF3m stability in lung adenocarcinoma .
To investigate eIF3m's role in RNA stress granule dynamics:
Stress induction protocols:
Oxidative stress: 0.5 mM sodium arsenite (30-60 minutes)
ER stress: 2 μg/mL tunicamycin (4-6 hours)
Heat shock: 42°C for 1 hour
UV irradiation: 20-40 J/m²
Co-localization analysis:
Live-cell imaging approach:
Generate cells expressing fluorescently-tagged eIF3m
Validate expression with eIF3m antibody
Perform time-lapse imaging during stress induction/recovery
Quantify granule formation, size, and dissolution kinetics
Functional impact assessment:
This methodology enables comprehensive assessment of eIF3m's potential roles in stress response pathways through RNA granule dynamics, providing insights into cancer cell adaptation to stressful microenvironments.
To investigate eIF3m's role in specialized mRNA translation during cancer progression:
Translational efficiency analysis:
Polysome profiling:
Fractionate cell lysates on sucrose gradients
Collect fractions and extract RNA
Perform qRT-PCR for candidate transcripts
Compare distribution in eIF3m-modulated cells
Ribosome profiling:
Generate ribosome-protected fragment libraries
Perform deep sequencing
Analyze ribosome occupancy on specific transcripts
Compare translation efficiency between control and eIF3m-modulated cells
5'UTR-specific interactions:
CLIP-seq (Crosslinking and immunoprecipitation with sequencing):
Crosslink RNA-protein complexes
Immunoprecipitate with eIF3m antibody
Sequence bound RNA fragments
Identify enriched motifs and transcripts
Reporter assays:
Translation inhibitor sensitivity:
Test differential sensitivity to translation inhibitors:
mTOR inhibitors (rapamycin, torin)
eIF4A inhibitors (silvestrol, rocaglamide)
eIF2α phosphorylation inducers (salubrinal)
Assess effects on cell viability and proliferation
Correlate with eIF3m expression levels
This multifaceted approach has revealed that eIF3m binds specifically to the 5'UTR of oncogenic mRNAs like CAPRIN1, promoting their translation and contributing to cancer progression .
For comprehensive analysis of eIF3m post-translational modifications (PTMs):
PTM-specific detection strategies:
Phosphorylation analysis:
Immunoprecipitate with eIF3m antibody
Probe with phospho-specific antibodies (p-Ser, p-Thr, p-Tyr)
Perform phosphatase treatment controls
Use Phos-tag gels for mobility shift detection
Ubiquitination analysis:
Mass spectrometry approach:
Functional impact assessment:
Generate site-specific mutants (phospho-mimetic, phospho-dead)
Assess protein stability, localization, and interaction profile
Determine effects on target mRNA translation (CAPRIN1, etc.)
Correlate with cancer phenotypes (proliferation, invasion, metastasis)
Cancer context specificity:
This methodological framework enables comprehensive characterization of eIF3m PTMs and their functional significance in cancer progression, potentially revealing novel therapeutic targets for cancer intervention.
For optimizing signal-to-noise ratio with eIF3m antibody in challenging tissues:
Tissue-specific protocol optimization:
Fixation optimization:
Test multiple fixatives (PFA, formalin, Bouin's)
Vary fixation times (4-48 hours)
Implement post-fixation treatments
Antigen retrieval matrix:
Antibody conditioning approaches:
Pre-absorption with tissue extracts
Sequential antibody application
Signal amplification systems:
Tyramide signal amplification
Polymer-HRP detection systems
Biotin-free detection methods
Background reduction strategies:
Implement stringent blocking:
Use tissue-matched normal serum (5-10%)
Add 0.1-0.3% Triton X-100 to reduce hydrophobic interactions
Consider dual blocking (protein block followed by avidin/biotin block)
Washing optimization:
Extend washing times (3 × 10 minutes minimum)
Add 0.05-0.1% Tween-20 to all wash buffers
Implement high-salt wash steps
Validated detection approaches:
For IHC: Polymer-HRP systems minimize background
For IF: Use highly cross-adsorbed secondary antibodies
For challenging tissues: Consider multiple antibody application approach (primary → secondary → primary → secondary)
This systematic optimization approach ensures reliable detection of eIF3m across diverse tissue types, including pancreatic cancer tissues where positive signals have been validated .
For quantitative analysis of eIF3m expression in tissue microarrays (TMAs):
Image acquisition standardization:
Use consistent microscope settings:
Fixed exposure times
Standardized light intensity
Consistent objective magnification
Implement color calibration standards
Acquire multiple representative fields per core (minimum 3)
Image analysis workflow:
Tissue segmentation:
Define regions of interest (tumor vs. stroma)
Implement nuclear counterstain-based cell identification
Exclude areas with artifacts/edge effects
Expression quantification:
DAB intensity measurement (for IHC)
H-score calculation (% positive cells × intensity score)
Automated positive cell counting
Advanced analytical approaches:
Machine learning-based classification:
Train algorithms to recognize positive cells
Implement pattern recognition for subcellular localization
Correlate with morphological features
Multiplexed analysis:
Co-registration with sequential staining of same section
Correlation with other markers (Ki67, oncogenic proteins)
Statistical analysis framework:
This quantitative approach enables objective assessment of eIF3m expression across large patient cohorts, facilitating correlation with clinical parameters and outcomes as demonstrated in lung adenocarcinoma studies .
To investigate therapeutic vulnerabilities related to eIF3m in cancer:
Target validation strategies:
Synthetic lethality screening:
CRISPR-based approaches:
Generate eIF3m knockout cell lines
Perform genome-wide CRISPR screens in eIF3m-high vs. eIF3m-low backgrounds
Validate hits with individual sgRNAs
Pathway-specific vulnerability assessment:
Biomarker development:
This comprehensive approach can identify novel therapeutic strategies targeting eIF3m-dependent vulnerabilities in cancer, potentially leading to more effective personalized treatment approaches.
For applying eIF3m antibody in single-cell protein analysis:
Single-cell Western blot optimization:
Mass cytometry (CyTOF) implementation:
Metal conjugation of eIF3m antibody
Panel design with cancer-relevant markers
Signal-to-noise optimization
Data analysis using dimensionality reduction (tSNE, UMAP)
Clustering algorithms for cell population identification
Microfluidic-based approaches:
Droplet-based single-cell protein secretion assays
Antibody barcoding for multiplexed detection
Microfluidic antibody capture chip design
Integration with transcriptomic analysis
Statistical frameworks for multiparametric data
Imaging-based single-cell analysis:
These methodologies enable unprecedented insights into cell-to-cell variation in eIF3m expression and its relationship to cancer heterogeneity, potentially revealing subpopulations with distinct therapeutic vulnerabilities or prognostic significance.