RPL7L1 (ribosomal protein L7-like 1) is a 29 kDa protein consisting of 246 amino acids that plays significant roles in cellular processes. Unlike standard ribosomal proteins directly involved in translation, RPL7L1 functions extend beyond structural roles in the ribosome.
The protein has been identified as aberrantly overexpressed in multiple tumor types including hepatocellular carcinoma (LIHC), lung adenocarcinoma (LUAD), colon adenocarcinoma (COAD), glioblastoma multiforme (GBM), breast cancer (BRCA), and head and neck squamous cell carcinoma (HNSC) . Functionally, research indicates that RPL7L1 can promote the proliferation and migration of tumor cells, suggesting its role in cancer progression .
Additionally, RPL7L1 appears to influence the tumor microenvironment by suppressing anti-tumor immunity, particularly by increasing immunosuppressive cells like cancer-associated fibroblasts (CAFs) and myeloid-derived suppressor cells (MDSCs) in certain cancers . Its expression is frequently higher in later tumor stages, suggesting potential involvement in disease progression mechanisms.
RPL7L1 antibodies are utilized across multiple research applications, each providing distinct insights into protein expression, localization, and interactions. The primary applications include:
Western Blot (WB): RPL7L1 antibodies are extensively validated for WB applications with recommended dilution ranges of 1:2000-1:16000 for polyclonal antibodies (16707-1-AP) or 1:2000-1:10000 for recombinant antibodies (84907-1-RR) . Western blotting allows for the detection and semi-quantification of RPL7L1 in various cell lines including HEK-293T, HeLa, HepG2, and MCF-7 cells.
Immunoprecipitation (IP): For studying protein-protein interactions, RPL7L1 antibodies are recommended at 0.5-4.0 μg for 1.0-3.0 mg of total protein lysate, with positive detection demonstrated in HepG2 cells .
Immunohistochemistry (IHC): For tissue analysis, particularly in cancer research, dilutions of 1:20-1:200 are recommended, with positive detection shown in human liver cancer tissue .
Immunofluorescence (IF/ICC): For cellular localization studies, dilutions of 1:10-1:100 are suggested, with validated results in MCF-7 cells .
ELISA: Both polyclonal and recombinant antibodies are suitable for ELISA applications, enabling quantitative protein detection .
For optimal results in each application, titration is necessary as sensitivity varies depending on experimental conditions and sample types.
Proper storage and handling of RPL7L1 antibodies are crucial for maintaining their reactivity and specificity over time. The recommended storage conditions are:
When handling the antibodies, avoid contamination, minimize exposure to light for conjugated antibodies, and always centrifuge briefly before opening vials to ensure that all liquid is collected at the bottom of the tube.
The relationship between RPL7L1 expression and cancer prognosis shows remarkable tissue and cancer-type specificity, providing important implications for its potential use as a prognostic biomarker:
Research suggests that RPL7L1's prognostic value derives from its complex interactions within the tumor microenvironment and potential influence on anti-tumor immune responses, rather than simply its expression level alone.
RPL7L1 demonstrates significant immunomodulatory functions within the tumor microenvironment, with potential implications for immunotherapy approaches:
Immunosuppressive cell recruitment: High RPL7L1 expression has been found to suppress anti-tumor immunity by increasing immunosuppressive cells including cancer-associated fibroblasts (CAFs) and myeloid-derived suppressor cells (MDSCs) particularly in hepatocellular carcinoma (LIHC), head and neck squamous cell carcinoma (HNSC), and breast cancer (BRCA) .
Immune and stromal correlation: RPL7L1 expression negatively correlates with immune cell infiltration and stromal scores in multiple cancer types, suggesting a role in creating an immunosuppressive microenvironment .
MHC interaction: RPL7L1 shows strong negative correlations with major histocompatibility complex (MHC) expression particularly in acute myeloid leukemia (LAML), thyroid carcinoma (THCA), testicular germ cell tumors (TGCT), neuroblastoma (TARGET-NB), and diffuse large B-cell lymphoma (DLBC) . This suggests RPL7L1 may affect antigen presentation and subsequent T-cell responses.
Effector and suppressor cell balance: The protein exhibits negative correlations with effector cells in thyroid carcinoma (THCA), lung squamous cell carcinoma (LUSC), testicular germ cell tumors (TGCT), and several other cancer types, while showing positive correlations with suppressor cells in most tumor types except LAML, kidney renal papillary cell carcinoma (KIRC), pancreatic adenocarcinoma (PAAD), and a few others .
Checkpoint regulation: RPL7L1 shows varying associations with immune checkpoint molecules across cancer types, with positive associations particularly strong in testicular germ cell tumors (TGCT) and uterine carcinosarcoma (UCS) .
These findings suggest RPL7L1 may serve as an important target for modulating anti-tumor immunity and potentially enhancing immunotherapy responses.
The methylation status of RPL7L1 demonstrates critical regulatory control over its expression and function, with significant tissue-specific variations that influence disease progression:
Expression regulation: Methylation plays a key role in regulating RPL7L1 expression across different tissues and cancer types. Hypermethylation and hypomethylation patterns correlate with expression levels in a tissue-dependent manner .
Cancer-specific patterns: In hepatocellular carcinoma (LIHC), kidney renal clear cell carcinoma (KIRC), sarcoma (SARC), and uterine corpus endometrial carcinoma (UCEC), hypermethylation of RPL7L1 correlates with poor prognosis. Conversely, in head and neck squamous cell carcinoma (HNSC) and lung squamous cell carcinoma (LUSC), hypomethylation correlates with poor outcomes .
Functional consequences: The methylation status likely affects RPL7L1's interaction with transcription factors, chromatin modifiers, and other epigenetic regulators, thereby altering its downstream signaling pathways and cellular functions in tissue-specific ways.
Clinical relevance: The differential methylation patterns provide potential for using RPL7L1 methylation status as a biomarker for cancer detection and prognosis prediction. The tissue-specific nature of these correlations suggests that methylation analysis should be contextualized within specific cancer types.
Therapeutic implications: Understanding methylation-dependent regulation of RPL7L1 may offer opportunities for epigenetic therapies targeting RPL7L1 expression in cancers where its dysregulation contributes to disease progression.
For researchers, analyzing both expression and methylation status provides more comprehensive insights into RPL7L1's role in disease processes than examining either parameter alone.
Optimizing antibody dilutions and protocols for RPL7L1 detection requires consideration of the specific application, sample type, and antibody format. Here are evidence-based recommendations:
Western Blot (WB):
For polyclonal antibodies (e.g., 16707-1-AP): Use dilutions of 1:2000-1:16000
For recombinant antibodies (e.g., 84907-1-RR): Use dilutions of 1:2000-1:10000
Sample loading: 20-30 μg of total protein per lane is typically sufficient
Validated in multiple cell lines including HEK-293T, HeLa, HepG2, and MCF-7 cells
Immunoprecipitation (IP):
Immunohistochemistry (IHC):
Immunofluorescence (IF/ICC):
ELISA:
Both polyclonal and recombinant antibodies are suitable
Coating concentration: typically 1-2 μg/ml for capture antibody
Detection antibody: 0.5-1 μg/ml
For all applications, it is essential to include proper positive and negative controls and to titrate antibodies for each experimental system to achieve optimal signal-to-noise ratios.
Establishing antibody specificity is crucial for generating reliable and reproducible results in RPL7L1 research. The following comprehensive validation approach is recommended:
Multiple antibody validation:
Genetic controls:
CRISPR/Cas9 knockout: Generate RPL7L1 knockout cell lines as negative controls
siRNA/shRNA knockdown: Demonstrate reduced signal following RPL7L1 knockdown
Overexpression: Show increased signal in RPL7L1-overexpressing cells
Blocking peptide experiments:
Mass spectrometry validation:
Perform immunoprecipitation followed by mass spectrometry to confirm the antibody captures RPL7L1
Identify any potential cross-reactive proteins
Western blot analysis:
Cross-reactivity assessment:
Epitope mapping:
Determine the exact epitope recognized by the antibody to predict potential cross-reactivity
This can be done through peptide arrays or alanine scanning mutagenesis
Application-specific validations:
For IHC: Compare with RNA expression data (ISH or single-cell RNA-seq)
For IF: Co-localization with known interaction partners or cellular compartments
Implementing these validation steps ensures confidence in experimental results and facilitates troubleshooting when inconsistencies arise.
Effective sample preparation significantly influences RPL7L1 detection sensitivity and specificity across different experimental platforms. Optimize your preparations with these technique-specific approaches:
Cell lysate preparation for Western blot and immunoprecipitation:
Lysis buffer: RIPA buffer (50 mM Tris-HCl pH 7.4, 150 mM NaCl, 1% NP-40, 0.5% sodium deoxycholate, 0.1% SDS) with protease inhibitors
Include phosphatase inhibitors if studying phosphorylation states
Sonication: Brief sonication (3-5 pulses) helps solubilize nuclear proteins
Centrifugation: 14,000 × g for 15 minutes at 4°C to remove debris
Protein quantification: BCA or Bradford assay before loading
Denaturation: Heat samples at 95°C for 5 minutes in Laemmli buffer with β-mercaptoethanol
Tissue sample preparation for IHC:
Fixation: 10% neutral buffered formalin for 24-48 hours
Processing: Standard paraffin embedding
Sectioning: 4-5 μm sections on positively charged slides
Antigen retrieval: TE buffer pH 9.0 is recommended, with citrate buffer pH 6.0 as an alternative
Blocking: 5-10% normal serum from the same species as the secondary antibody
Background reduction: 0.3% H₂O₂ treatment to block endogenous peroxidases
Cell preparation for immunofluorescence:
Culturing: Grow cells on coverslips or chamber slides to 60-80% confluence
Fixation: 4% paraformaldehyde for 15 minutes at room temperature
Permeabilization: 0.1-0.5% Triton X-100 for 10 minutes
Blocking: 1-5% BSA in PBS for 30-60 minutes
Primary antibody incubation: Overnight at 4°C at recommended dilutions (1:10-1:100)
Nuclear counterstain: DAPI (1 μg/ml) for 5 minutes
Fresh/frozen tissue preparation:
Flash freezing: Liquid nitrogen with OCT compound
Sectioning: 6-10 μm cryosections
Fixation: Acetone or 4% paraformaldehyde
Protein extraction: Tissue homogenization in RIPA buffer using mechanical disruption
Preservation of protein modifications:
For phosphorylation: Include phosphatase inhibitors (sodium fluoride, sodium orthovanadate)
For ubiquitination: Include deubiquitinase inhibitors (N-ethylmaleimide)
For preventing protein degradation: Maintain samples at 4°C throughout processing
These optimized preparation techniques ensure maximal preservation of RPL7L1 epitopes and minimize background interference, resulting in more sensitive and specific detection across experimental platforms.
Designing robust experiments to elucidate RPL7L1's role in cancer progression requires multi-faceted approaches that address both mechanistic understanding and clinical relevance:
Expression modulation studies:
Knockdown approaches: siRNA, shRNA, or CRISPR/Cas9 to create RPL7L1-deficient cancer cell lines
Overexpression systems: Transfection with RPL7L1 expression vectors under constitutive or inducible promoters
Rescue experiments: Re-expression of RPL7L1 in knockout cells to confirm phenotype specificity
Functional assays to assess cancer hallmarks:
Proliferation: MTT/XTT assays, BrdU incorporation, colony formation
Migration/invasion: Transwell assays, wound healing assays, 3D invasion models
Apoptosis resistance: Annexin V/PI staining, caspase activation assays
Stemness: Tumorsphere formation assays, stem cell marker expression
Tumor microenvironment investigations:
Co-culture systems: RPL7L1-modified cancer cells with immune cells or fibroblasts
Conditioned media experiments: Assess paracrine effects on immune cells
Immune cell recruitment/function assays: Flow cytometry analysis of immunosuppressive cell populations (Tregs, MDSCs, CAFs)
Cytokine profiling: Multiplex analysis of secreted factors in response to RPL7L1 modulation
In vivo models:
Xenograft models: Subcutaneous or orthotopic implantation of RPL7L1-modified cancer cells
Syngeneic models: For investigating immune system interactions
Patient-derived xenografts: To validate findings in clinically relevant models
Metastasis models: Tail vein or intracardiac injection to assess metastatic potential
Multi-omics approaches:
Transcriptomics: RNA-seq to identify RPL7L1-dependent gene expression programs
Proteomics: Mass spectrometry to identify interaction partners and affected signaling pathways
Epigenomics: ChIP-seq or ATAC-seq to investigate chromatin changes
Integration with patient data: Correlation with TCGA datasets for clinical relevance
Methylation-focused experiments:
Translational relevance:
Tissue microarray analysis: RPL7L1 expression in patient samples with clinical annotation
Biomarker potential: Correlation with treatment response, particularly immunotherapies
Development of RPL7L1-targeting therapeutic strategies
This comprehensive experimental design framework enables researchers to systematically investigate RPL7L1's multifaceted roles in cancer progression and identify potential therapeutic vulnerabilities.
Implementing rigorous controls and validation steps is crucial for generating reliable and reproducible results when using RPL7L1 antibodies in cancer research:
Antibody validation controls:
Positive tissue/cell controls: Include known RPL7L1-expressing samples such as HEK-293T, HeLa, HepG2, and MCF-7 cells
Negative controls: Use tissues/cells with low/no RPL7L1 expression or knockdown/knockout models
Isotype controls: Include matched isotype (rabbit IgG) to evaluate non-specific binding
Absorption controls: Pre-incubate antibody with immunizing peptide to confirm specificity
Multiple antibody validation: Compare results from different antibody clones (e.g., polyclonal 16707-1-AP vs. recombinant 84907-1-RR)
Technical controls for each method:
Western blot: Loading controls (β-actin, GAPDH), molecular weight markers, no-primary antibody control
IHC/IF: No-primary antibody controls, isotype controls, counterstaining for tissue architecture
IP: IgG control IP, input sample controls, non-specific binding assessment
Quantitative comparisons: Standard curves with recombinant RPL7L1 protein
Biological validation approaches:
Genetic modification: Confirm antibody signal reduction in RPL7L1 knockdown/knockout models
Correlation with mRNA: Compare protein detection with RT-qPCR results
Orthogonal detection methods: Validate findings using alternative techniques (e.g., mass spectrometry)
Functional validation: Correlate RPL7L1 detection with expected biological functions
Cancer-specific considerations:
Tissue context validation: Compare RPL7L1 detection across multiple cancer types known to express different levels
Tumor heterogeneity assessment: Evaluate RPL7L1 expression across different regions of tumors
Patient-derived materials: Validate findings in primary patient samples in addition to cell lines
Clinical correlation: Link expression patterns to clinical parameters from databases like TCGA
Reproducibility measures:
Biological replicates: Use samples from multiple patients/donors
Technical replicates: Repeat experiments multiple times
Blinded analysis: Have independent researchers score or quantify results
Statistical validation: Apply appropriate statistical tests with adequate sample sizes
Reporting standards:
Detailed antibody information: Include catalog numbers, lot numbers, dilutions, and incubation conditions
Comprehensive methods description: Enable other researchers to reproduce protocols exactly
Raw data sharing: Provide unmodified blots/images in publications
Transparent limitations discussion: Acknowledge potential caveats in interpretation
These controls and validation steps ensure that findings related to RPL7L1 in cancer research are robust, reliable, and biologically meaningful, facilitating translation to clinical applications.
Investigating RPL7L1's interaction with the tumor immune microenvironment requires sophisticated experimental approaches that bridge molecular biology, immunology, and cancer biology:
Multiparametric flow cytometry analysis:
Design panels to simultaneously assess RPL7L1 expression and immune cell populations
Quantify correlations between RPL7L1 levels and immunosuppressive cells (Tregs, MDSCs, M2 macrophages)
Measure immune checkpoint molecule expression (PD-1, PD-L1, CTLA-4) in relation to RPL7L1 status
Analyze functional markers (cytokine production, proliferation, activation markers) of T cells in RPL7L1-high versus RPL7L1-low tumors
Co-culture experimental systems:
Direct co-culture: RPL7L1-modulated cancer cells with isolated immune cell populations
Transwell systems: To assess effects mediated by soluble factors
3D organoid co-cultures: More physiologically relevant models incorporating stromal components
Readouts: Immune cell proliferation, cytokine production, cytotoxicity assays, migration assays
Secretome analysis:
Cytokine arrays or multiplex assays: Measure changes in immunomodulatory cytokine production
ELISA validation: Confirm key findings for specific cytokines
Mass spectrometry: Unbiased profiling of secreted factors from RPL7L1-modified cells
Functional testing: Determine biological activity of conditioned media on immune cell functions
In vivo immune profiling:
Syngeneic mouse models with RPL7L1-modified cancer cells
Flow cytometry of tumor-infiltrating lymphocytes and myeloid cells
Immunohistochemistry multiplex: Spatial relationship between RPL7L1+ cells and immune infiltrates
Response to immunotherapy: Test how RPL7L1 status affects checkpoint inhibitor efficacy
Single-cell approaches:
scRNA-seq of tumor ecosystems: Correlate RPL7L1 expression with immune cell states
CyTOF/mass cytometry: High-dimensional profiling of tumor-immune interactions
Spatial transcriptomics: Map RPL7L1 expression relative to immune niches within tumors
Cellular indexing of transcriptomes and epitopes (CITE-seq): Simultaneous measurement of surface proteins and gene expression
Molecular mechanism investigation:
ChIP-seq: Identify transcription factors regulating immune genes in response to RPL7L1
Pathway analysis: Signal transduction pathways affected by RPL7L1 that influence immune response
Proximity labeling: Identify proteins interacting with RPL7L1 in the context of immune regulation
CRISPR screens: Identify genes required for RPL7L1-mediated immunomodulation
Clinical correlation approaches:
Multiplex IHC on patient samples: Correlate RPL7L1 expression with immune infiltrates
Transcriptomic data mining: Analyze correlation between RPL7L1 and immune signatures in TCGA datasets
Immunotherapy response prediction: Test RPL7L1 as a biomarker for checkpoint inhibitor efficacy
Meta-analysis: Integrate findings across cancer types to identify common immune-related mechanisms
These methodologies provide comprehensive insights into how RPL7L1 modulates anti-tumor immunity, potentially identifying novel therapeutic targets and biomarkers for personalized immunotherapy approaches.
Interpreting discrepancies in RPL7L1 detection requires systematic investigation of multiple biological and technical factors that may contribute to divergent results:
Epitope-specific differences:
Map the epitopes recognized by different antibodies (e.g., N-terminal vs. C-terminal)
Consider post-translational modifications that may mask specific epitopes
Evaluate potential protein isoforms or splice variants recognized differentially
Assess accessibility of epitopes in different experimental conditions (native vs. denatured)
Sample preparation effects:
Fixation impact: Formalin fixation can mask epitopes differently than frozen preparations
Antigen retrieval methods: Compare results with different retrieval buffers (TE buffer pH 9.0 vs. citrate buffer pH 6.0)
Protein extraction efficiency: Different lysis buffers may extract RPL7L1 with varying efficiency
Processing artifacts: Consider tissue-specific factors that might affect protein preservation
Antibody performance characteristics:
Sensitivity thresholds: Different antibodies may have varying detection limits
Dynamic range: Evaluate linearity of signal across concentration ranges
Clone-specific behaviors: Polyclonal (16707-1-AP) may detect multiple epitopes versus more specific recombinant antibodies (84907-1-RR)
Lot-to-lot variability: Document antibody lot numbers when comparing results
Technical platform differences:
Western blot vs. IHC: Detection of denatured linear epitopes versus conformational epitopes
Dilution optimization: Ensure each antibody is used at its optimal dilution for each technique
Detection systems: DAB vs. fluorescent secondary antibodies may have different sensitivities
Quantification methods: Image analysis parameters can influence interpretation
Biological context considerations:
Cell/tissue-specific expression patterns: RPL7L1 may be differentially expressed or localized
Cancer-specific alterations: Gene mutations or copy number variations may affect detection
Methylation status: Epigenetic regulation may influence expression in different samples
Microenvironmental factors: Tumor heterogeneity or stress conditions may alter expression
Resolution approaches:
Orthogonal validation: Confirm with non-antibody methods (mass spectrometry, RNA-seq)
Sequential analysis: Use multiple antibodies on the same samples in sequence
Genetic controls: Validate with RPL7L1 knockdown/knockout models
Standardization: Develop reference standards with known quantities of recombinant RPL7L1
Interpretation framework:
Document all variables systematically when comparing results
Consider biological relevance of each detection method for the research question
Integrate findings rather than dismissing discrepancies
Acknowledge limitations transparently in research communications
This systematic approach to interpreting discrepancies not only resolves conflicting data but can reveal novel insights about RPL7L1 biology, post-translational modifications, or context-specific functions that may be relevant to its role in cancer progression.
The differential expression of RPL7L1 across cancer types and stages reveals complex biological roles with significant implications for diagnosis, prognosis, and therapeutic targeting:
The diverse expression patterns and prognostic associations of RPL7L1 across cancer types underscore the need for context-specific interpretation and targeted therapeutic approaches rather than a one-size-fits-all strategy.
Distinguishing direct from indirect effects of RPL7L1 on cancer progression requires sophisticated experimental approaches and careful data interpretation:
Temporal analysis frameworks:
Inducible expression systems: Use doxycycline-inducible RPL7L1 expression to monitor immediate versus delayed responses
Time-course experiments: Track changes in cellular phenotypes, gene expression, and signaling at multiple time points after RPL7L1 modulation
Pulse-chase designs: Transiently express RPL7L1 and monitor persistence of effects after expression ceases
Live-cell imaging: Visualize real-time consequences of RPL7L1 expression changes
Molecular mechanism delineation:
Direct binding partners: Identify proteins that physically interact with RPL7L1 using co-immunoprecipitation, proximity labeling (BioID/APEX), or yeast two-hybrid screening
Chromatin association: ChIP-seq to determine if RPL7L1 directly associates with chromatin regions
Post-translational modifications: Investigate how RPL7L1 might directly modify other proteins
Structure-function analysis: Create domain mutants to map regions responsible for specific functions
Pathway dissection approaches:
Phosphoproteomic analysis: Identify signaling cascades activated immediately after RPL7L1 modulation
Transcription factor activity: Assess which transcription factors are directly activated/repressed
Rescue experiments: Test if downstream effector expression can rescue phenotypes in RPL7L1-depleted cells
Inhibitor studies: Use pathway-specific inhibitors to block potential mediators of RPL7L1 effects
Cell-autonomous versus non-cell-autonomous effects:
Conditioned media experiments: Test if secreted factors from RPL7L1-modified cells affect naive cells
Co-culture systems: Determine if RPL7L1 expression in cancer cells directly affects neighboring cells
In vivo parabiosis models: Share circulation between mice bearing RPL7L1-high and RPL7L1-low tumors
Single-cell analysis: Correlate RPL7L1 expression with cell states in heterogeneous populations
Genetic interaction mapping:
Synthetic lethality screens: Identify genes whose loss specifically affects RPL7L1-high or RPL7L1-low cells
Genetic epistasis: Test if phenotypes of known cancer genes depend on RPL7L1 status
CRISPR activation/inhibition screens: Find genes that modify RPL7L1-dependent phenotypes
Genome-wide association studies: Correlate genetic variants with RPL7L1 expression in patient cohorts
Multi-omics integration:
Integrated network analysis: Build causal networks from transcriptomic, proteomic, and metabolomic data
Machine learning approaches: Train algorithms to distinguish direct from indirect targets based on multi-omic signatures
Comparative analysis across cancer types: Identify conserved versus context-specific effects
Temporal multi-omics: Track changes across multiple molecular levels over time after RPL7L1 modulation
Translational validation:
Patient-derived models: Validate mechanisms in primary patient samples
Correlation with clinical parameters: Assess if proposed direct targets correlate with RPL7L1 and outcomes in patient data
Therapeutic intervention: Test if targeting proposed direct mechanisms mimics RPL7L1 modulation effects
Biomarker development: Develop assays for direct RPL7L1 effectors as companion diagnostics
This multi-faceted approach enables researchers to construct mechanistic models that distinguish primary effects of RPL7L1 from secondary consequences, facilitating more precise therapeutic targeting and understanding of its role in cancer progression.