SLC16A3, also known as monocarboxylate transporter 4 (MCT4), facilitates proton-coupled transport of monocarboxylates like lactate and pyruvate. It maintains intracellular pH by exporting lactate, a process vital in glycolytic tissues and cancer metabolism .
| Basic Information | Details |
|---|---|
| Protein Name | Monocarboxylate transporter 4 |
| Gene Name | SLC16A3 |
| UniProt ID | O15427 |
| Transmembrane Domains | 12 |
| Key Function | Lactate efflux, pH regulation, glycolytic metabolism support |
Pancreatic Cancer: SLC16A3 upregulation correlates with glycolytic metabolism and poor prognosis .
Neuroendocrine Prostate Cancer: Inhibition reduces lactic acid secretion, suggesting therapeutic potential .
Oral Squamous Cell Carcinoma: Knockdown decreases proliferation and metastasis .
Macrophage Activation: Sustains glycolysis required for inflammatory responses .
Hepatocellular Carcinoma: Modulates HIF-1α and AKT signaling pathways .
Selectivity: Prestige Antibodies® (e.g., HPA021451) show minimal cross-reactivity due to stringent antigen selection .
Functional Assays: Rescue experiments in HAP1 cells confirm antibody specificity to SLC16A3-dependent phenotypes .
SLC16A3, also known as MCT4 or MCT-4, is a member of the monocarboxylate transporter family responsible for the transport of lactate and other monocarboxylates like pyruvate. It is a proton-dependent transporter that plays a predominant role in L-lactate efflux from highly glycolytic cells . The protein is approximately 49.5 kilodaltons in mass and is encoded by the SLC16A3 gene in humans . Its importance in research stems from its critical role in cancer metabolism, particularly in maintaining glycolytic activity in tumors, making it a potential therapeutic target and biomarker in various cancers .
While both SLC16A1 (MCT1) and SLC16A3 (MCT4) transport monocarboxylates, they have distinct functional differences:
Synthetic lethality between SLC16A1 and SLC16A3 occurs when the loss or inhibition of both transporters leads to cell death, while the loss of either one alone is tolerated. This relationship has been leveraged in a screening strategy called paralog-dependent isogenic cell assay (PARADISO) to develop specific inhibitors of SLC16A3 . The system involves isogenic cell lines engineered to be dependent on various paralog genes for survival/fitness. When SLC16A1 is knocked out, cells become dependent on SLC16A3 function, creating a model system for identifying selective SLC16A3 inhibitors .
SLC16A3 antibodies are predominantly used in:
Western Blotting (WB): For detecting SLC16A3 protein in cell or tissue lysates
Immunohistochemistry (IHC): For visualizing SLC16A3 expression in tissue sections
Immunocytochemistry/Immunofluorescence (ICC/IF): For cellular localization studies
ELISA: For quantitative detection in solution
According to the search results, commercially available antibodies are validated for these applications with varying species reactivity, primarily human, mouse, and rat samples . When selecting an antibody, researchers should consider the specific application needs and validated reactivity with their species of interest.
When selecting an SLC16A3 antibody, researchers should consider:
Epitope location: Some antibodies target specific regions (e.g., N-terminal vs. C-terminal). The ab244385 antibody targets a recombinant fragment within human SLC16A3 aa 400 to C-terminus .
Species reactivity: Verify cross-reactivity with your experimental model. Many antibodies react with human, mouse, and rat SLC16A3 .
Clonality: Polyclonal antibodies offer broader epitope recognition but may have batch-to-batch variability; monoclonal antibodies provide consistency but may be more sensitive to epitope changes.
Validated applications: Ensure the antibody has been validated for your specific application (WB, IHC, IF, etc.).
Published references: Check if the antibody has been cited in publications similar to your research context .
For optimal SLC16A3 detection:
Western Blotting:
Use appropriate lysis buffers containing detergents to solubilize membrane proteins
Include protease inhibitors to prevent degradation
Consider reducing agents to break disulfide bonds
Avoid excessive heating which may cause membrane protein aggregation
Immunohistochemistry:
Immunofluorescence:
Common issues include:
Weak or no signal:
Increase antibody concentration
Extend incubation time
Optimize antigen retrieval methods
Use signal amplification systems
Verify expression levels in your sample with reference data
Non-specific binding:
Increase blocking time/concentration
Optimize antibody dilution
Use more stringent washing conditions
Verify antibody specificity with positive and negative controls
Variable results between experiments:
Standardize protocols
Use consistent antibody lots
Include internal controls
Normalize data appropriately
Validation approaches include:
Genetic approaches:
Use SLC16A3 knockout cells/tissues as negative controls
Use SLC16A3 overexpression systems as positive controls
Compare with siRNA/shRNA knockdown samples
Analytical approaches:
Cross-species validation:
When testing cross-species reactivity:
Sequence analysis:
Perform BLAST analysis between the immunogen sequence and the target species
Evaluate homology percentage in the epitope region
Pilot testing:
Start with standard protocols optimized for validated species
Use positive control samples from the validated species alongside test samples
Consider using gradient dilutions of antibody to find optimal concentration
Include appropriate negative controls
Validation confirmation:
SLC16A3 antibodies can be utilized to:
For studying SLC16A3 in tumor progression:
Expression analysis across cancer stages:
Functional studies:
Use genetic manipulation (knockdown/overexpression) combined with antibody detection
Evaluate effects on invasion, migration, and extracellular matrix organization
SLC16A3-associated genes are enriched in pathways related to extracellular matrix organization, leukocyte trans-endothelial migration, and regulation of actin cytoskeleton
Mechanistic investigations:
Study co-localization with other glycolytic enzymes
Evaluate metabolite profiles in relation to SLC16A3 expression
Investigate lactate dynamics in the tumor microenvironment
When designing combination studies:
Expression profiling:
Synthetic lethality approaches:
Inhibitor studies:
Use selective inhibitors like AZD3965 (SLC16A1 inhibitor) and slCeMM1 (SLC16A3 inhibitor)
Evaluate synergistic effects of combined inhibition
Consider genetic approaches (siRNA, CRISPR) alongside pharmacological inhibition
SLC16A3 expression patterns across cancers:
This expression data suggests SLC16A3 could be a valuable prognostic marker across multiple cancer types, with particularly strong evidence in prostate and ovarian cancers.
The relationship between genomic alterations and protein expression is complex:
This indicates researchers should not rely solely on genomic data when studying SLC16A3 and should incorporate transcriptomic and proteomic approaches.
Approaches for targeting SLC16A3 in cancer therapy:
Direct inhibition strategies:
Synthetic lethality approaches:
Biomarker-guided therapy:
Stratifying patients based on SLC16A3 expression levels
Correlating expression with response to metabolism-targeting drugs
Developing companion diagnostics using validated antibodies
These strategies highlight the potential of SLC16A3 as both a therapeutic target and a prognostic/predictive biomarker in personalized cancer medicine.
Essential controls include:
Positive controls:
Negative controls:
SLC16A3 knockout cells/tissues
Primary antibody omission controls
Isotype controls matching the primary antibody species/class
Tissues known to have low/no expression
Specificity controls:
Peptide competition assays
siRNA knockdown samples
Multiple antibodies targeting different epitopes
Including these controls ensures reliable interpretation of SLC16A3 antibody results across different experimental systems.
For quantitative tissue analysis:
Immunohistochemistry quantification:
Use digital pathology platforms for objective scoring
Establish clear scoring criteria (intensity, proportion of positive cells)
Consider automated image analysis software
Include appropriate normalization controls
Western blot quantification:
Use housekeeping proteins appropriate for your tissue/condition
Consider membrane protein-specific loading controls
Perform densitometry with linear range validation
Include concentration standards if possible
Statistical considerations:
Use appropriate statistical tests for your data distribution
Consider paired analyses for tumor/normal comparisons
Account for clinical variables in multivariate analyses
Report effect sizes along with p-values
When studying multiple SLC16 family members:
Antibody specificity:
Ensure antibodies do not cross-react between family members
Validate specificity in systems with differential expression
Consider epitope mapping to confirm targeted regions
Functional redundancy:
Co-expression analysis:
These considerations help researchers accurately interpret complex relationships between SLC16 family members in biological systems.