Paracrine growth factor and cytokine pathways

Paracrine growth factor and cytokine pathways represent a fundamental mode of intercellular communication where cells secrete signaling molecules that act on nearby target cells within the local environment. These pathways involve a vast array of ligands, including cytokines (e.g., interleukins, interferons) and growth factors (e.g., VEGF, FGF), which bind to specific cell-surface receptors to initiate intracellular signaling cascades (Alberts et al., Molecular Biology of the Cell). In physiological contexts, these pathways are essential for coordinating immune responses, promoting tissue repair, and regulating cell proliferation. However, their dysregulation is a hallmark of various pathologies; for example, in the tumor microenvironment, aberrant paracrine signaling facilitates angiogenesis and immune evasion, while overactive cytokine loops drive chronic inflammation and autoimmunity (Nature Reviews Drug Discovery, 2020). Because this term describes a broad biological mechanism rather than a single protein or receptor, it is not classified as a specific therapeutic target. Instead, clinical interventions focus on modulating individual components of these pathways, such as using monoclonal antibodies to neutralize specific cytokines or small-molecule inhibitors to block receptor tyrosine kinase activity (PubMed, PMID: 32111600).

Other names

Paracrine signalingCytokine signalingGrowth factor signalingLocal intercellular signaling

Inhibition of specific ligand-receptor interactions or downstream signaling cascades within local tissue environments.