Discovery Of New Sigma-2 Receptor Agonist Endowed With Antiproliferative Activity

Sigma receptors (σR) have proved to be an attractive pharmacological target for the treatment of several pathologies. In particular, σ1 ligands have been considered to play an important role in the treatment of various neurological disorders, including depression, schizophrenia, neuropathic pain, Alzheimer's and Parkinson’s disease. Moreover, it has been found that σR are involved in the modulation of cellular proliferation and cell death and σ1 antagonists and σ2 agonists may represent useful tools as anticancer and tumor imaging agents. Recently, we reported that a properly substituted 1,3-dioxolane moiety could be employed as suitable scaffold for developing ligands for both σ1R and σ2R.1 In this work we explore a new set of structural related analogues obtained by combining different substituted spiro-heterocyclic rings with appropriate σR pharmacophoric amines. Radioligand binding assay, performed on guinea pig brain membranes, identified BS148 (1-(1,4-ditiaspiro[4.5]decan-2-ylmethyl)-4-benzylpiperidne) as the most interesting compound of the series, displaying good affinity and selectivity for σ2R .The ability of BS148 to modulate the analgesic effect of the agonist morphine was evaluated in-vivo by radiant heat tail-flick test. It exhibited anti-opioid effects on receptor-mediated analgesia, suggesting an agonistic behavior at σ1R. Moreover, BS148 demonstrated to affect the growth (MTT test) of SK-MEL-28 and SK-MEL-2 melanoma cell lines in comparison to siramesine, suggesting an agonistic behavior at σ2R. The present work represents a new starting point for the design of potential therapeutically useful agents