PD 168368 is a competitive antagonist of neuromedin B (NMB) receptors (Ks = 15-45 nM for rat and human receptors expressed in various cell lines). It blocks the elevation of intracellular calcium and release of inositol phosphate induced by NMB in cells expressing NMB receptors. PD 168368 is selective for NMB receptors over those for related peptide agonists, including bombesin and gastrin-releasing peptide. It is also an agonist of formyl-peptide receptors (FPRs) at higher concentrations (ECs = 0.57 and 0.24 µM for FPR1 and FPR2, respectively). PD 168368 induces cell cycle arrest and apoptosis in MDA-MB-231 breast cancer cells and blocks neovascularization and cancer cell growth in breast cancer xenograft tumors in mice.
PD 168368 is a potent, competitive, and selective neuromedin B receptor (NMB-R) antagonist with the Ki of 15–45 nM. PD 168368 is neuromedin B receptor (NMBR; IC50=96 nM) / gastrin-releasing peptide receptor (GRPR IC50=3500 nM) antagonist. PD 168368 also is a mixed FPR1/FPR2/FPR3 agonist with EC50s of 0.57, 0.24, and 2.7 nM, respectively.
体外研究
PD 168368 has high activity and stimulates the release of [Ca2+] I in human neutrophils, with EC50 values in the nanomolar range.
PD 168368 inhibits the migration and invasion of human breast cancer cell line MDA-MB-231. PD 168368 reduces epithelial mesenchymal transformation (EMT) of breast cancer cells through up regulation of E-cadherin and down regulation of vimentin. PD 168368 (5 μM) inhibits the migration and invasion of breast cancer cells.
PD 168368 (10 μM) inhibits the activation of mTOR/p70S6K/4EBP1 and AKT/GSK-3 β in breast cancer cells.
Cell Viability Assay
Cell Line:
Human breast cancer cell line MDA-MB-231
Concentration:
5 μM
Incubation Time:
24 hours
Result:
Clearly decreased the migratory ability of MDA-MB-231 cells in a Boyden chamber migration assay.
Cell Viability Assay
Cell Line:
MDA-MB-231 cells
Concentration:
10 μM
Incubation Time:
0, 0.5, 1, 2, 4, 8, and 16 hours
Result:
Decreased phosphorylation levels of mTOR, p70S6K, 4EBP1, AKT and GSK-3β in a time-dependent manner.
体内研究
PD 168368 effectively inhibits the metastasis of breast cancer in vivo. PD 168368 (1.2 mg/kg; intraperitoneal injection for 30 days) inhibits the metastasis of breast cancer in mice.
Animal Model:
Female BALB/c-nude mice (age 8-10 weeks) bearing MDA-MB-231 xenograft model
Dosage:
1.2 mg/kg
Administration:
Intraperitoneal injection for 30 days
Result:
No metastatic tumor nodules were observed in lungs of PD 168368-treated mice compared to PEG-injected mice.