PB 28 dihydrochloride, a cyclohexylpiperazine derivative, is sigma (σ) receptor ligand, acting as a σ2 receptor agonist with a Ki value of 0.68 nM, as well as a σ1 receptor antagonist with a Ki of 0.38 nM. The σ receptor, composed of σ1 and σ2 subtypes, is present with high density in central nervous system and peripheral organs, and overexpressed in many tumor cell lines. Selective σ2 receptor agonists have been proposed as anticancer drugs, while selective σ1 receptor ligands have been proposed to develop new classes of central nervous system agents for neuroprotection, anxiety, depression, psychosis, as well as learning and memory improvement.
References:
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2. Azzariti A, Colabufo NA, Berardi F, et al. Cyclohexylpiperazine derivative PB28, a sigma2 agonist and sigma1 antagonist receptor, inhibits cell growth, modulates P-glycoprotein, and synergizes with anthracyclines in breast cancer. Molecular Cancer Therapeutics, 2006, 5(7): 1807-1816.
3. Pati ML, Hornick JR, Niso M, et al. Sigma-2 receptor agonist derivatives of 1-Cyclohexyl-4-[3-(5-methoxy-1,2,3,4-tetrahydronaphthalen-1-yl)propyl]piperazine (PB28) induce cell death via mitochondrial superoxide production and caspase activation in pancreatic cancer. BMC Cancer, 2017, 17(1): 51.