AFPep

**AFPep** is an orally active, cyclic 9-amino acid peptide (sequence cyclo(EKTOVNOGN), molecular weight 969 Da) derived from the anti-oncogenic active site (residues 472-479) of alpha-fetoprotein (AFP). It exhibits antiestrogenic properties by binding heat shock protein Hsp72, disrupting the Hsp72-Hsp90 heterocomplex with the estrogen receptor, inhibiting estrogen receptor phosphorylation, and activating p53 phosphorylation, thereby suppressing proliferation of estrogen receptor-positive (ER+) breast cancer cells in vitro and in rodent xenograft and chemically induced models. AFPep prevents and treats mammary tumors in mice, rats, and dogs, enhances tamoxifen efficacy while reducing its uterine hyperplasia side effects, and shows excellent tolerability with achievable blood levels (e.g., >0.1 μg/mL) via oral, subcutaneous, or intraperitoneal routes; it has no disruptive effects on rat estrous cycle or fertility.

Other names

alpha fetoprotein peptide