Secreted frizzled-related protein 1 (SFRP1)

Secreted frizzled-related protein 1 (SFRP1) is a secreted glycoprotein and member of the frizzled-related protein family, characterized by a cysteine-rich domain homologous to the Wnt-binding region of Frizzled receptors. SFRP1 functions as a soluble antagonist of canonical Wnt signaling by directly binding Wnt ligands, preventing receptor activation, and reducing β-catenin levels. Regulation by SFRP1 impacts cell growth, differentiation, cell cycle progression, apoptosis, and tissue patterning—especially in cancer, where loss or silencing of SFRP1 leads to unchecked Wnt pathway activation. Additional functions involve retinal cell polarity, angiogenesis, and possible roles in fibrotic disease. SFRP1 is considered a putative therapeutic target, especially in oncology and regenerative medicine.

Other names

FRP-1SARP2FrzASARP-2FRP1secreted apoptosis-related protein 2sFRP-1frizzled-related protein

Antagonism of Wnt ligands via binding and sequestration. Inhibition of β-catenin signaling downstream of Wnt pathway. Modulation of cell cycle (delays G1 phase, inhibits entry into S phase). Inhibition of WNT1/WNT4-mediated TCF-dependent transcription.