Cellular Communication Network Factor 5 (CCN5) (CCN5)

Cellular Communication Network Factor 5 (CCN5), also known as WNT1-inducible-signaling pathway protein 2 (WISP2), is a secreted matricellular protein and a member of the CCN family (Wikipedia, GeneCards). It is structurally distinct from other CCN proteins as it lacks the C-terminal cysteine knot domain, which is associated with its unique anti-fibrotic and tumor-suppressive properties (Nature Reviews Drug Discovery, 2011). CCN5 plays a pivotal role in maintaining tissue homeostasis by regulating cell proliferation, migration, and differentiation through the modulation of key signaling cascades, most notably the inhibition of the TGF-beta/SMAD pathway and the activation of canonical Wnt signaling (NIH, 2025). In disease states, CCN5 is a critical regulator of fibrosis and cancer progression. It acts as a potent anti-fibrotic agent in the heart and liver by inhibiting the activation of fibroblasts into myofibroblasts and selectively inducing apoptosis in myofibroblasts (Jeong et al., 2016). In oncology, particularly in breast cancer, CCN5 functions as a tumor suppressor that inhibits the epithelial-mesenchymal transition (EMT) and can restore the expression of the estrogen receptor in aggressive triple-negative subtypes, thereby potentially sensitizing them to endocrine therapies (Banerjee et al., 2012). Therapeutic approaches currently under investigation include gene therapy (AAV-CCN5), modified mRNA, and CCN5-derived peptides (e.g., CDP199) aimed at restoring CCN5 activity to treat heart failure, metabolic disorders, and various cancers (NIH, 2025).

Other names

WNT1-inducible-signaling pathway protein 2WISP2WISP-2Connective tissue growth factor-like proteinCTGF-LCTGFLCOP1CCN family member 5

Therapeutic strategies targeting the CCN5 pathway primarily focus on restoring CCN5 levels to inhibit TGF-beta/SMAD signaling, thereby preventing fibroblast-to-myofibroblast transition and inducing myofibroblast apoptosis (Jeong et al., 2016). In cancer, CCN5-mediated inhibition of the PI3K-AKT pathway stabilizes FOXO3A and activates P27KIP1 to induce growth arrest (Banerjee et al., 2012). It also modulates canonical Wnt signaling to regulate adipogenesis and insulin sensitivity (Grunberg et al., 2017).