Extracellular matrix components and fibroblast cell-surface proteins

The target group 'Extracellular matrix components and fibroblast cell-surface proteins' refers to a broad class of molecules that constitute the structural and functional environment of cells, particularly within the tumor microenvironment and fibrotic tissues (PubMed: 30694151). This group includes structural proteins like collagens and fibronectin, glycosaminoglycans such as hyaluronan, and specialized cell-surface markers on activated fibroblasts, most notably Fibroblast Activation Protein alpha (FAP) and Endo180 (CD280) (UniProt: Q12884, Q9UBG0). These components play critical roles in tissue architecture, cell signaling, and the regulation of immune cell infiltration. In diseases like cancer, the extracellular matrix (ECM) often becomes dense and cross-linked, a process known as desmoplasia, which creates a physical barrier to chemotherapy and promotes an immunosuppressive milieu (PubMed: 29101163). Therapeutic interventions targeting this group aim to 'reprogram' the stroma by degrading ECM barriers, inhibiting the pro-fibrotic activity of fibroblasts, or utilizing stromal-specific antigens for the targeted delivery of potent payloads like radionuclides or antibody-drug conjugates. For example, Pegvorhyaluronidase alfa was developed to deplete hyaluronan in pancreatic cancer, while FAP-targeted radiopharmaceuticals like 68Ga-FAPI-04 are used for highly sensitive tumor imaging (Journal of Nuclear Medicine, 2018). While promising for treating desmoplastic tumors and fibrotic diseases, targeting these ubiquitous components poses significant challenges regarding systemic toxicity and the maintenance of normal tissue integrity, as many of these proteins are essential for healthy wound healing and connective tissue homeostasis.

Other names

Tumor stromaExtracellular matrix (ECM)Cancer-associated fibroblast (CAF) markersStromal microenvironment components

Therapeutic strategies involve the enzymatic degradation of matrix components to improve drug penetration, the inhibition of fibroblast-mediated tissue remodeling, and the use of stromal-specific proteins as docking sites for targeted delivery of cytotoxic or imaging agents.