Pilose antler (PA) is a traditional Chinese functional food that has been reported to inhibit
breast cancer; however, the specific substances that exert this effect and the underlying mechanisms remain unknown. This study aims to identify the specific
proteins in PA water-soluble
polypeptides (PAWPs) that are involved in
cancer inhibition and determine the effects of PAWPs on
triple-negative breast cancer in mice. In this study, peptidomic analysis of 105 varieties of
polypeptides from PAWPs was carried out using LC-MS, 22 of which had functions that could potentially suppress
tumors, including
endopeptidase inhibitors,
metal ion-
binding proteins,
angiogenesis inhibitors, intercellular adhesion
proteins, and extracellular matrix repair
proteins. Furthermore, we showed that intragastric administration of PAWPs into mice inhibited the growth and
metastasis of triple-negative 4T1
breast tumors. PAWPs activated the expression of cleaved-caspase3 and increased
tumor apoptosis, resulting in the reduction of platelet-endothelial cell adhesion molecule (PECAM-1/CD31) expression and the number of blood vessels, as well as the inhibition of
matrix metalloproteinase (
MMP) 2 and 9, increasing the ratio of
Cadherin-1 (CDH1)/
Cadherin-2 (CDH2) and inhibiting epithelial-mesenchymal transition (EMT) in these
tumors. Therefore, PAWPs inhibit the progression and
metastasis of triple-negative 4T1
breast cancer at multiple key sites in mice and contain various
tumor suppressor proteins that are potentially involved in these processes.