Chapter 3. The adenoviral vector angiogenesis/lymphangiogenesis assay

Area of Science:

• Vascular biology
• Molecular medicine
• Regenerative medicine

Background:

• Pathological angiogenesis and lymphangiogenesis are key in diseases like cancer.
• Understanding the formation of abnormal vasculature is crucial for developing targeted therapies.
• Adenoviral vectors offer a method to deliver genetic material for studying these processes.

Purpose of the Study:

• To investigate the utility of adenoviral vectors expressing VEGF-A(164) in modeling pathological angiogenesis and lymphangiogenesis.
• To characterize the distinct types of abnormal blood and lymphatic vessels induced by Ad-VEGF-A(164).
• To establish a screening assay for evaluating pro- and anti-angiogenic therapies.

Main Methods:

• Injection of adenoviral vectors expressing VEGF-A(164) (Ad-VEGF-A(164)) into various tissues of nude mice and rats.
• Visual monitoring of angiogenic and lymphangiogenic responses, particularly in ear injection sites.
• Characterization of induced vessel types including mother vessels, capillaries, glomeruloid microvascular proliferations, vascular malformations, feeding arteries, and draining veins.

Main Results:

• Ad-VEGF-A(164) induced six distinct types of abnormal blood vessels and "giant" lymphatics.
• The assay allowed elucidation of the mechanisms and steps of new vessel formation.
• Ear injection sites provided a convenient model for visual, real-time assessment of therapeutic efficacy and toxicity.

Conclusions:

• Adenoviral vectors expressing VEGF-A(164) provide a robust model for studying pathological angiogenesis and lymphangiogenesis.
• The Ad-VEGF-A(164) assay is a valuable tool for screening anti- and pro-angiogenic agents.
• This methodology can be extended to study other growth factors and cytokines involved in neovascularization.