Modeling human tumor angiogenesis in a three-dimensional culture system

Area of Science:

• Biomedical Engineering
• Cell Biology
• Vascular Biology

Background:

• Cellular assays for studying vessel formation (angiogenesis) have limitations in elucidating molecular and pharmacologic mechanisms.
• A need exists for more effective models to study human angiogenesis.

Purpose of the Study:

• To develop and validate an ex vivo three-dimensional (3D) assay of sprouting angiogenesis using human arterial explants.
• To assess the utility of this assay for drug screening and functional genomics.

Main Methods:

• Human umbilical cord arterial rings were embedded in basement membrane extract gel and stimulated with vascular endothelial growth factor A.
• Vascular network formation was quantified using computer-assisted analysis.
• Gene knockdown was performed using lentiviral vectors carrying short-hairpin RNA.
• A 3D model of tumor-driven angiogenesis was developed using prostate cancer cell spheroids.

Main Results:

• The assay successfully generated capillary-like structures composed of endothelial cells and pericytes.
• The model demonstrated sensitivity to known angiogenic inhibitors, including kinase inhibitors and monoclonal antibodies.
• Downregulation of VEGFR2 significantly reduced sprouting, validating the model for functional genomics.
• The modified assay supported tumor-driven angiogenesis without exogenous growth factors.

Conclusions:

• The human arterial ring assay provides a robust platform for studying human angiogenesis ex vivo.
• This 3D model bridges the gap between in vitro cell cultures and animal models.
• The assay is valuable for identifying novel genes and therapeutic agents regulating angiogenesis.