Imaging tumor angiogenesis with fluorescent proteins.

Area of Science:

• Biomedical Imaging
• Cancer Biology
• Molecular Biology

Background:

• Angiogenesis, the formation of new blood vessels, is crucial for tumor growth and metastasis.
• Current imaging techniques for angiogenesis often lack the resolution and sensitivity required for detailed study.
• Fluorescent proteins offer a powerful tool for non-invasive, real-time visualization of biological processes.

Purpose of the Study:

• To develop and describe three unique mouse models for in vivo imaging of angiogenesis using fluorescent proteins.
• To demonstrate the utility of these models for studying tumor-induced angiogenesis and tumor-stroma interactions.
• To highlight the advantages of fluorescent protein-based imaging for high-resolution, sensitive detection of blood vessel development.

Main Methods:

• Surgical orthotopic implantation (SOI) model with green fluorescent protein (GFP)-labeled human tumors in nude mice.
• Dual-color fluorescence imaging using red fluorescent protein (RFP)-expressing tumors in GFP-expressing transgenic mice.
• Transgenic nestin-GFP mice for visualizing nascent vessels in specific tumor types, such as melanoma.

Main Results:

• The SOI model clearly visualizes angiogenic capillaries in primary and metastatic human tumors, with vessel density increasing over time.
• Dual-color imaging effectively distinguishes tumor cells from host vasculature, detailing tumor-stroma interactions.
• Nestin-GFP mice enable specific visualization of nascent vessels in skin tumors, offering high resolution and sensitivity.

Conclusions:

• Fluorescent protein-based mouse models provide high-resolution, sensitive, real-time imaging of angiogenesis.
• These models significantly advance the study of tumor vascularization and related biological processes.
• The developed models offer powerful tools for preclinical cancer research and therapeutic development.