CYP4X1 Antibody

What applications are CYP4X1 antibodies validated for in laboratory research?

CYP4X1 antibodies have been validated for multiple applications in research settings, including:

• Western Blotting (WB): Typically used at dilutions of 1:500-1:2000

• Enzyme-Linked Immunosorbent Assay (ELISA): Used at dilutions up to 1:40000

• Immunohistochemistry (IHC): Used at dilutions of 1:100-1:300 for paraffin-embedded tissue sections

• Immunofluorescence (IF): Validated for cellular localization studies

• Immunocytochemistry (ICC): For examining expression in cultured cells

When selecting an application, consider that different antibodies may perform optimally in specific applications. For example, ABIN6258079 is validated for WB, ELISA, IHC, IF, and ICC, while NBP2-13896 is specifically validated for WB, IHC, and IHC-Paraffin .

What is the typical reactivity profile of commercially available CYP4X1 antibodies?

Most commercially available CYP4X1 antibodies exhibit reactivity with human samples, with many also cross-reacting with mouse tissue. Specific reactivity profiles include:

• Human-only reactive antibodies: Several antibodies including PA5-49924 and PA5-75379

• Human and mouse cross-reactive antibodies: ABIN6258079 and others

• Human, mouse, and rat cross-reactive antibodies: Some antibodies like PA5-75379 show broader species reactivity

• Human and monkey cross-reactive antibodies: ABIN3184204 shows this pattern

When planning experiments involving multiple species, select antibodies with validated cross-reactivity. For example, if working with both human and mouse samples, ABIN6258079 would be appropriate as it detects endogenous levels of CYP4X1 in both species .

What are the optimal storage and handling conditions for CYP4X1 antibodies?

For maximum stability and performance of CYP4X1 antibodies:

• Storage temperature: Store at -20°C for long-term preservation

• Buffer composition: Most are supplied in PBS containing 50% glycerol, 0.5% BSA, and 0.02% sodium azide as preservative

• Handling precautions:

  • Avoid repeated freeze/thaw cycles as this can significantly reduce antibody activity

  • Work with aliquots rather than the entire stock when possible

  • Follow safety precautions as many contain sodium azide, which is hazardous

Note that some antibodies, such as those from Thermo Fisher Scientific, have specific storage recommendations that should be followed according to the manufacturer's guidelines .

How should CYP4X1 expression be evaluated in immunohistochemistry studies of cancer tissues?

For reliable immunohistochemical evaluation of CYP4X1 in cancer tissues:

• Sample preparation: Use formalin-fixed, paraffin-embedded tissue sections

• Scoring methodology: Implement a standardized scoring system combining:

  • Staining intensity: 0 (no expression), 1 (mild), 2 (moderate), or 3 (strong)

  • Percentage of positive cells: 0 (0-10%), 1 (11-30%), 2 (31-50%), or 3 (51-100%)

• Final score calculation: Multiply the intensity score by the percentage score

• Interpretation: Classify as high-expression (score ≥4) or low-expression (score <4)

This scoring method was effectively used in the 2025 study of 243 colorectal cancer patients, where high CYP4X1 expression significantly correlated with nodal metastasis (p<0.001), distant metastasis (p=0.004), and advanced clinical stage (p<0.001) .

What controls should be included when performing Western blot analysis of CYP4X1?

For rigorous Western blot validation of CYP4X1:

• Positive controls:

  • CYP4X1 overexpression lysate (e.g., HEK293T cells transfected with CYP4X1)

  • Tissues known to express CYP4X1 (aorta, trachea, or skeletal muscle samples)

• Negative controls:

  • Vector-only transfected cell lysates

  • Tissues with minimal CYP4X1 expression

  • Samples treated with CYP4X1 siRNA (showing knockdown efficiency)

• Loading controls:

  • β-actin is commonly used (1:1000 dilution of anti-β-actin antibody)

• Expected band size: Approximately 50 kDa for human CYP4X1

• SDS-PAGE conditions:

  • 10% gels are appropriate for resolving CYP4X1

  • Load approximately 30 μg of total protein per lane for optimal detection

How can CYP4X1 knockdown be achieved for functional studies in cancer cell lines?

Based on recent successful implementations, CYP4X1 knockdown can be achieved through:

• siRNA-mediated transient knockdown:

  • Transfect cells with CYP4X1-specific siRNA

  • Verify knockdown efficiency by Western blot 48-72 hours post-transfection

  • This approach achieved 23-67% inhibition of cell proliferation in colorectal cancer cell lines (SW480, SW620, HCT116, and HT29)

• shRNA-mediated stable knockdown:

  • Transfect cells with pGFP-C-shLenti vector containing CYP4X1-targeted shRNA

  • Select stable transfectants

  • Verify knockdown efficiency (>90% reduction was achieved in the recent HCT116 study)

• Functional assays that can be performed post-knockdown:

  • Proliferation assays (e.g., WST-1 assay)

  • Migration and invasion assays (Transwell assay)

  • Colony formation assays

  • In vivo tumor growth in xenograft models

How does CYP4X1 expression correlate with clinicopathological features in cancer patients?

Comprehensive analysis of CYP4X1 expression across multiple cancer types reveals distinct patterns:

• Colorectal cancer (CRC):

  • Significantly higher expression in CRC tissues compared to normal tissues (p<1×10^-12)

  • Elevated expression in stage 4 (distant metastasis) compared to normal tissues (p<1.20×10^-3)

  • Strong correlation with:

    • Advanced TNM stage

    • Poor tumor differentiation

    • Deeper invasion

    • Lymph node metastasis (p<0.001)

• Expression patterns in other cancers:

  • Higher in cancer vs. normal tissues: rectal adenocarcinoma (READ), colon adenocarcinoma (COAD), and endometrial/cervical cancers

  • Lower in cancer vs. normal tissues: esophageal carcinoma, glioblastoma, head/neck squamous cell carcinoma, kidney cancers, and thyroid carcinoma

• Demographic correlations:

  • Significant expression differences based on:

    • Race (p ranges from 2.78×10^-2 to 1.95×10^-12)

    • Gender (p<1.43×10^-10)

    • Age (most significant in 61-80y group, p<1.43×10^-11)

    • Weight (significant in all categories except extreme obese)

Table 1 from the 2025 study provides a comprehensive statistical breakdown of these correlations, making it valuable for researchers investigating CYP4X1 as a biomarker .

What is the subcellular localization pattern of CYP4X1 and how should staining patterns be interpreted?

CYP4X1 demonstrates specific subcellular localization patterns that are important for accurate interpretation:

• In colorectal cancer tissues:

  • High levels of staining primarily on the cell membrane

  • Lower expression observed in the cytoplasm

• In uterine/cervical tissues:

  • Nuclear and cytoplasmic positivity in glandular cells

• Interpretation guidelines:

  • Membrane staining is particularly significant in colorectal cancer and may indicate functional activity

  • Nuclear staining patterns should be carefully evaluated as they might represent specific functional states of the protein

  • Cytoplasmic staining is expected due to CYP4X1's role as a member of the cytochrome P450 family

• When evaluating IHC slides:

  • Consider both intensity and distribution of staining

  • Compare with known positive controls

  • Be aware that staining patterns may differ between cancer types and normal tissues

How can researchers distinguish between the functions of CYP4X1 and the closely related CYP4Z1 in cancer studies?

Both CYP4X1 and CYP4Z1 are members of the cytochrome P450 family 4 and show involvement in cancer, but they have distinct characteristics:

What mechanisms explain the relationship between CYP4X1 expression and cancer progression?

The mechanistic relationship between CYP4X1 and cancer progression is still being elucidated, but current evidence suggests:

• Arachidonic acid metabolism connection:

  • CYP4X1 is involved in the metabolism of arachidonic acid derivatives

  • These derivatives function as vital signaling mediators in immune, neuronal, and cardiovascular functions

  • Specifically, arachidonoyl ethanol amide (anandamide), a natural endocannabinoid, appears to be involved

• Cell proliferation mechanisms:

  • CYP4X1 knockdown studies in colorectal cancer cell lines demonstrated:

    • Significant reduction in proliferation rates at 24, 48, and 72 hours post-transfection

    • The inhibitory effect ranges from 23.31% to 67.32% depending on the cell line

    • HT29 cells showed the highest sensitivity to CYP4X1 knockdown (67.32% reduction at 24h)

• Tumor formation regulation:

  • In vitro: CYP4X1 knockdown reduces colony formation in soft agar by 75-84.5%

  • In vivo: Xenograft studies showed significantly smaller tumor masses and slower tumor growth in CYP4X1 knockdown HCT116 cells compared to control cells (p<0.001)

• Biomarker implications:

  • High CYP4X1 expression correlates with shorter survival times in cancer patients

  • The protein serves as an independent prognostic marker

Further research is needed to fully elucidate the signaling pathways and molecular interactions through which CYP4X1 influences cancer cell behavior.

What are the common challenges in detecting CYP4X1 in Western blotting and how can they be addressed?

When working with CYP4X1 in Western blotting, researchers commonly encounter these challenges and solutions:

• Low signal intensity:

  • Increase protein loading (30 μg recommended)

  • Optimize primary antibody concentration (try 1:500-1:2000 dilution range)

  • Extend primary antibody incubation (overnight at 4°C is effective)

  • Use enhanced chemiluminescence (ECL) detection systems with increased sensitivity

• Non-specific bands:

  • Select antibodies with higher specificity, such as those purified by peptide affinity chromatography

  • Increase blocking time and concentration (5% BSA has been effective)

  • Include additional washing steps

  • Use antibodies targeting specific regions of CYP4X1 (internal region antibodies often show better specificity)

• Variable results across cell lines:

  • Expression levels of CYP4X1 vary significantly between different cell types

  • Include positive controls (e.g., CYP4X1 overexpression lysate)

  • Standardize protein extraction methods across experiments

  • Consider cell-specific optimization of detection protocols

• Expected molecular weight confirmation:

  • CYP4X1 should appear at approximately 50 kDa

  • Use a molecular weight marker to confirm band identity

  • For recombinant proteins, note that tags (such as myc-DDK) will add to the molecular weight

How can researchers validate the specificity of CYP4X1 antibodies in their experimental systems?

To ensure antibody specificity for CYP4X1 in your experimental system:

• Multiple antibody validation approach:

  • Use antibodies targeting different epitopes of CYP4X1

  • Compare staining/detection patterns across antibodies

  • Confirm consistent results with antibodies from different manufacturers or clones

• Knockdown/knockout controls:

  • Perform siRNA-mediated knockdown of CYP4X1 (>90% reduction is achievable)

  • Verify reduction/elimination of signal in knockdown samples

  • Include scrambled siRNA as negative control

• Peptide competition assay:

  • Pre-incubate the antibody with the immunizing peptide

  • The specific signal should be significantly reduced or eliminated

  • Non-specific binding will remain unaffected

• Cross-reactivity testing:

  • Test the antibody in systems where CYP4X1 expression is known to be absent

  • Verify the antibody doesn't cross-react with other CYP family members, particularly the closely related CYP4Z1

  • Consider testing in multiple species if cross-species reactivity is claimed

• Correlation of protein and mRNA expression:

  • Compare antibody detection results with mRNA expression data from qPCR

  • Similar patterns provide additional validation of specificity

What methodological considerations are important when comparing CYP4X1 expression across different cancer types?

When conducting comparative studies of CYP4X1 expression across cancer types, implement these methodological safeguards:

• Standardized tissue processing:

  • Use identical fixation protocols for all samples

  • Standardize antigen retrieval methods

  • Process all samples simultaneously when possible

• Balanced control inclusion:

  • Include matched normal tissues for each cancer type

  • Use universal positive controls across all batches

  • Include technical controls to account for staining variability

• Quantification standardization:

  • Apply consistent scoring criteria (as described in section 2.1)

  • Use digital image analysis when possible to reduce subjective interpretation

  • Have multiple trained observers score independently (as done in the 2025 study with three observers)

• Data normalization considerations:

  • Account for baseline differences in protein expression between tissue types

  • Consider using tissue-specific reference proteins for normalization

  • Report both raw and normalized data for transparency

• Statistical analysis approaches:

  • Use appropriate statistical tests for different data types

  • Account for multiple comparisons when analyzing across numerous cancer types

  • Consider demographic factors that may influence expression (as shown in the comprehensive analysis of CYP4X1 in colorectal cancer patients)

The 2025 study demonstrated significant differences in CYP4X1 expression across cancer types, with higher expression in colorectal, rectal, and endometrial/cervical cancers, but lower expression in esophageal, brain, head/neck, kidney, and thyroid cancers compared to their respective normal tissues .

How might CYP4X1 serve as a therapeutic target in cancer treatment?

The potential of CYP4X1 as a therapeutic target is supported by recent findings:

• Rationale for targeting CYP4X1:

  • Significantly overexpressed in multiple cancer types including colorectal cancer

  • Knockdown studies demonstrate substantial inhibition of cancer cell proliferation, invasion, and tumor formation

  • Associated with poor prognosis, suggesting clinical relevance

• Potential therapeutic approaches:

  • Small molecule inhibitors specific to CYP4X1

  • siRNA/shRNA-based therapeutics for CYP4X1 knockdown

  • Antibody-drug conjugates targeting CYP4X1-expressing cells

  • Combination therapies targeting CYP4X1 alongside standard chemotherapeutics

• Considerations for drug development:

  • Selectivity over other CYP450 family members will be crucial

  • Understanding CYP4X1's role in normal tissues to predict potential side effects

  • Delivery methods to ensure tumor-specific targeting

• Patient stratification strategies:

  • IHC-based screening for CYP4X1 expression levels

  • Correlation with TNM staging and metastatic status

  • Integration with other biomarkers for precision medicine approaches

The 2025 xenograft study showing reduced tumor growth with CYP4X1 knockdown provides compelling preliminary evidence supporting therapeutic targeting of this protein .

What are the most promising methodological approaches for studying the enzymatic function of CYP4X1?

To address the current knowledge gap regarding CYP4X1's enzymatic functions:

• Substrate identification approaches:

  • Untargeted metabolomics to identify changes in metabolite profiles after CYP4X1 knockdown/overexpression

  • In vitro enzyme assays with recombinant CYP4X1 and candidate substrates

  • Focus on arachidonic acid derivatives, particularly anandamide, which has been implicated in CYP4X1 function

• Structural biology techniques:

  • X-ray crystallography or cryo-EM to determine CYP4X1 structure

  • In silico molecular docking studies to predict substrate binding

  • Site-directed mutagenesis of key residues to confirm functional predictions

• Protein-protein interaction studies:

  • Immunoprecipitation followed by mass spectrometry

  • Proximity labeling approaches (BioID or APEX)

  • Investigation of potential interactions with other CYP450 enzymes or redox partners

• Cellular localization studies:

  • High-resolution microscopy to determine precise subcellular localization

  • Correlation between localization and function

  • Investigation of potential membrane associations and microdomains

• Physiological context investigations:

  • Conditional knockout models to study tissue-specific functions

  • Patient-derived xenografts to preserve tumor heterogeneity

  • Integration of multi-omics data to place CYP4X1 in relevant pathways

These approaches could help resolve CYP4X1's classification as an "orphan" CYP450 and provide mechanistic insights into its role in cancer progression.

How can researchers better integrate CYP4X1 expression data with other molecular markers for improved cancer prognosis?

For comprehensive integration of CYP4X1 with other molecular markers:

• Multi-marker panel development:

  • Combine CYP4X1 with established prognostic markers for specific cancer types

  • Investigate synergistic information from combining markers

  • Develop weighted algorithms for prognostic scoring

• Correlation with genomic alterations:

  • The 2025 study showed significant differences in CYP4X1 expression based on TP53 mutation status (p<1.13×10^-9 for TP53-Mutant)

  • Explore additional correlations with common cancer mutations

  • Investigate potential regulatory mechanisms affecting CYP4X1 expression

• Integration with clinical parameters:

  • Develop multivariate models incorporating:

    • CYP4X1 expression levels

    • TNM staging

    • Histological grade

    • Patient demographic factors

    • Treatment response data

• Technical considerations for multi-marker analysis:

  • Standardize quantification methods across markers

  • Consider multiplexed detection approaches

  • Validate marker combinations in independent cohorts

• Bioinformatic approaches:

  • Machine learning algorithms to identify optimal marker combinations

  • Network analysis to understand relationships between markers

  • Pathway enrichment to place markers in biological context