Collagen (Tumor Extracellular Matrix) (COL)

Collagen is the primary structural component of the tumor extracellular matrix (ECM), particularly in desmoplastic cancers such as pancreatic, breast, and lung carcinomas. In the tumor microenvironment, collagen undergoes extensive remodeling, characterized by increased deposition, linearization, and cross-linking, which creates a dense physical barrier that elevates interstitial fluid pressure and impedes the delivery of chemotherapeutic agents and infiltrating immune cells (Fang et al., 2014, Journal of Hematology & Oncology). Beyond its role as a physical scaffold, collagen serves as a bioactive ligand that triggers intracellular signaling pathways through receptors like integrins and discoidin domain receptors (DDRs), promoting tumor cell survival, epithelial-to-mesenchymal transition (EMT), and metastasis (Xu et al., 2019, ACS Nano). Targeting collagen involves several strategies: direct degradation using collagenases to enhance drug penetration, inhibiting collagen synthesis using drugs like Losartan which modulates TGF-beta signaling, or preventing matrix stiffening by inhibiting lysyl oxidase (LOX) (Chauhan et al., 2013, Nature Communications). While these approaches show promise in sensitizing tumors to standard therapies, significant challenges remain, including the risk of systemic side effects such as impaired wound healing and the paradoxical risk of promoting cancer cell escape by degrading the restrictive matrix (Lu et al., 2012, Cold Spring Harbor Perspectives in Biology). Consequently, current research focuses on tumor-specific delivery of collagen-modifying agents to balance efficacy and safety.

Other names

Tumor-associated collagenFibrillar collagenDesmoplastic collagenExtracellular matrix collagenType I collagenType III collagen

Therapeutic strategies include the enzymatic degradation of existing collagen fibers to reduce interstitial fluid pressure, inhibition of collagen biosynthesis (e.g., via TGF-beta or angiotensin signaling blockade), and inhibition of collagen cross-linking enzymes like lysyl oxidase (LOX) to normalize matrix stiffness.