Assessing Tumor Microenvironment of Metastasis Doorway-Mediated Vascular Permeability Associated with Cancer Cell Dissemination using Intravital Imaging and Fixed Tissue Analysis
June 26th, 2019
We describe two methods for assessing transient vascular permeability associated with tumor microenvironment of metastasis (TMEM) doorway function and cancer cell intravasation using intravenous injection of high-molecular weight (155 kDa) dextran in mice. The methods include intravital imaging in live animals and fixed tissue analysis using immunofluorescence.
Overview
This article describes two methods for assessing transient vascular permeability related to the tumor microenvironment of metastasis (TMEM) and cancer cell intravasation. The techniques include intravital imaging in live animals and fixed tissue analysis using immunofluorescence.
Key Study Components
Area of Science
- Neuroscience
- Oncology
- Vascular Biology
Background
- Understanding tumor vasculature is crucial for cancer research.
- Transient vascular permeability is linked to cancer cell dissemination.
- TMEM plays a significant role in the metastatic process.
- High-molecular weight dextran is used to evaluate vascular permeability.
Purpose of Study
- To develop methods for measuring TMEM-dependent vascular permeability.
- To assess the metastatic potential of tumors.
- To provide real-time insights into tumor microenvironment dynamics.
Methods Used
- Intravital imaging of live tumor-bearing mice.
- Fixed tissue analysis using immunofluorescence.
- Injection of high-molecular weight dextran (155 kDa).
- Assessment of tumor vasculature permeability.
Main Results
- The intravital imaging protocol provides real-time data on tumor dynamics.
- The fixed-tissue protocol allows for high throughput analysis.
- Both methods correlate with cancer cell dissemination.
- These protocols enable direct measurement of vascular permeability.
Conclusions
- The presented methods are effective for studying TMEM and metastasis.
- They can be utilized to evaluate the metastatic potential of tumors.
- These techniques enhance our understanding of tumor biology.
Frequently Asked Questions
Executive Industry Relevance
Assessing TMEM-mediated vascular permeability provides a direct readout of cancer cell dissemination potential, a critical inflection point in metastatic progression. These methods enable mechanistic de-risking of anti-metastatic strategies by quantifying transient vascular permeability linked to TMEM doorway activity. The combination of intravital imaging and fixed tissue analysis supports predictive confidence in preclinical target validation and pipeline prioritization.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Scientific Value: Enables interrogation of TMEM doorway formation and function as a therapeutic hypothesis in metastasis.
- Operational Value: Provides quantitative, spatially resolved measurements of vascular permeability to validate target engagement.
- Scientific Value: Supports biological de-risking by correlating TMEM activity with cancer cell dissemination in vivo.
Screening & Assay Development
- Scientific Value: Generates standardized, high-throughput extracellular Dextran extravasation readouts for compound screening.
- Operational Value: Fixed tissue protocol allows large tumor coverage without multiphoton imaging, increasing assay scalability.
- Scientific Value: Intravital imaging captures real-time kinetics of vascular leakage, enabling dynamic mechanism-of-action studies.
Translational & Preclinical Research
- Scientific Value: Links TMEM-mediated permeability to metastatic potential, supporting disease-relevant preclinical modeling.
- Operational Value: Enables pharmacologic intervention studies to assess impact of TMEM inhibitors on vascular permeability.
- Scientific Value: Provides continuity from discovery through preclinical validation by measuring functional microenvironmental outputs.
Pipeline & Workflow Integration
The method fits within the discovery continuum from target validation through lead identification to preclinical efficacy testing, particularly for anti-metastatic compounds.
- Discovery Biology: Supports hypothesis testing of TMEM-dependent mechanisms in cancer cell dissemination.
- Screening: Delivers reproducible, quantitative vascular permeability outputs for compound evaluation.
- Analytics: Generates extravascular Dextran area ratios as a normalized metric for comparing permeability across conditions.
- Translational Research: Connects TMEM function to metastatic behavior, informing risk-adjusted advancement decisions.
- Enterprise Reuse: Establishes a reusable platform for assessing vascular permeability across tumor models and therapeutic interventions.
Operational & Enterprise Impact
- Scientific Value: Predictive confidence in target validation through direct measurement of dissemination-linked vascular permeability.
- Operational Value: Standardization and reproducibility via fixed tissue analysis; dynamic insight via intravital imaging.
- Strategic Value: Improved go/no-go decisions by de-risking metastatic potential early in the pipeline.
- Portfolio Impact: Risk-adjusted prioritization of compounds based on TMEM pathway modulation efficacy.
Implementation Considerations
- Expertise in intravital imaging, surgical tumor implantation, and immunofluorescence staining.
- Instrumentation includes multiphoton microscope for live imaging and digital whole-slide scanner for fixed tissue.
- Cross-team standardization required for image acquisition, thresholding, and ROI analysis across sites.
- Adaptation considerations include model-specific vascular labeling and tumor piece preparation for transplantation.
- Practical limitations include surgical complexity and potential vascular damage during imaging window installation.
Biopharma FAQs
Chapters in this video
0:04
Title
0:55
Transplantation of Syngeneic Breast Tumors into Mouse Hosts with Fluorescent Macrophages
2:38
Preparation of Mouse for Imaging
4:25
Evaluation of Extravascular Dextran Using Fixed Tissue Analysis
7:10
Results: Visualization of Vasculature in Healthy and Diseased Tissues and TMEM-Mediated Vascular Permeability
8:56
Conclusion
