Breast cancer cell-derived matrix supports vascular morphogenesis

Area of Science:

• Biochemistry
• Cell Biology
• Oncology

Background:

• The extracellular matrix (ECM) is crucial for tissue homeostasis and is dysregulated in mammary tumors.
• ECM plays a significant role in angiogenesis, the formation of new blood vessels.

Purpose of the Study:

• To investigate how breast cancer cells (BCCs) deposit ECM and its impact on endothelial cell (EC) vascular morphogenesis.
• To determine if coculturing BCCs with fibroblasts enhances ECM deposition and supports capillary-like structure (CLS) formation.

Main Methods:

• Assessed ECM protein expression (collagens I and IV, fibronectin, laminin, tenascin-C) in nontumorigenic (MCF10A) and tumorigenic (MCF7, MDA-MB-231) BCC lines.
• Performed coculture experiments with BCCs and fibroblasts, analyzing deposited ECM and EC capillary formation.
• Evaluated CLS properties, including lumen diameter, area occupied, and expression of von Willebrand factor and E-selectin.

Main Results:

• BCCs expressed varying amounts and types of ECM proteins; however, deposited ECM was insufficient for EC CLS formation.
• Coculturing BCCs with fibroblasts altered ECM deposition and organization, enabling robust CLS formation.
• CLS grown on ECM from MDA-MB-231 and fibroblast cocultures exhibited larger lumens, greater area coverage, and higher expression of specific angiogenic markers.

Conclusions:

• Tumor cell-derived ECM significantly influences vascular morphogenesis and capillary properties.
• Fibroblast-mediated modulation of ECM is critical for supporting vascularization in the tumor microenvironment.
• This study provides a framework for understanding ECM's role in tumor angiogenesis and offers potential therapeutic targets.