Diverse Effects of Hypothalamic Proline-Rich Peptide (PRP-1) on Cell Death in Neurodegenerative and Cancer Diseases

Abstract

The proline-rich peptide (PRP-1) isolated from neurosecretory granules of the bovine neurohypophysis, produced by N.supraopticus and N.paraventricularis, has many potentially beneficial biological effects. PRP-1 has been shown to have the opposite effects on cell death in neurodegenerative and cancer diseases. It significantly reduces staurosporine-induced apoptosis of postnatal hippocampal cells, as well as doxorubicin-induced apoptosis of bone marrow monocytes and granulocytes, in both time- and dose-dependent manner. PRP-1 also exerts the opposite effect on the proliferation of bone marrow stromal cells obtained from normal humans and on the stromal cells isolated from human giant-cell tumor. PRP-1 cytostatically inhibits chondrosarcoma bulk tumor but exerts drastic cytotoxic effect on sarcomas cancer stem cells. The same peptide caused cell death through apoptosis in rats with Ehrlich Ascites Carcinoma model.