Tissue stromal and endothelial cells

Tissue stromal and endothelial cells constitute the essential structural and regulatory framework of the organ microenvironment. Stromal cells, predominantly fibroblasts, are responsible for the production of the extracellular matrix (ECM) and the secretion of various cytokines that maintain tissue architecture and facilitate repair (Source: NIH/NCBI). Endothelial cells form the interior lining of blood vessels, playing a pivotal role in vascular homeostasis, blood flow regulation, and the recruitment of inflammatory cells (Source: StatPearls). In the context of oncology, these cells are major components of the tumor microenvironment (TME), where they are often co-opted to support tumor growth, promote angiogenesis, and mediate immunosuppression (Source: Nature Reviews Cancer). Therapeutic strategies often focus on specific molecular targets within these populations, such as Vascular Endothelial Growth Factor (VEGF) or Fibroblast Activation Protein (FAP), rather than the cells as a whole. For instance, anti-angiogenic drugs like bevacizumab target VEGF to disrupt endothelial cell function and starve tumors of nutrients. Similarly, stromal-targeted therapies aim to inhibit the activation of cancer-associated fibroblasts to reduce tissue stiffness and improve drug delivery. Consequently, while these cells are critical to disease pathology and drug response, the term refers to a cellular collective rather than a single druggable molecule. This broad classification makes it a tissue compartment rather than a specific molecular target for drug development.

Other names

Stromal-vascular nicheNon-parenchymal tissue cellsTumor microenvironment cellsMesenchymal and vascular cell population

Drugs typically target specific receptors or ligands expressed by these cells, such as VEGF or PDGF receptors, to inhibit angiogenesis, disrupt the supportive tissue niche, or prevent fibroblast activation.