TcdB-FBD

TcdB-FBD (TcdB Frizzled-binding domain) is a non-toxic recombinant protein fragment derived from the Frizzled-binding domain of *Clostridioides difficile* toxin B (TcdB). It acts as a narrow-spectrum Wnt signaling inhibitor by specifically binding to Frizzled receptors 1, 2, and 7 (FZD1, FZD2, and FZD7). By binding to these receptors, TcdB-FBD competitively inhibits Wnt ligand binding and suppresses downstream Wnt/β-catenin signaling. It is being investigated by Shanghai Sixth People's Hospital for the treatment of breast cancer, particularly FZD7-high and chemotherapy-resistant subtypes, where it has shown potential to suppress tumor-initiating cells and synergize with chemotherapy without causing bone density-related adverse effects.

Other names

TcdB Frizzled-binding domainClostridioides difficile toxin B Frizzled-binding domainClostridium difficile toxin B Frizzled-binding domainTcdB-FZD binding domain