Migrastatin is a bacterial metabolite that has been found inStreptomyceswith antimuscarinic and anticancer activities.1,2It binds to M1-5muscarinic acetylcholine receptors (Kis = >200, 200, 31, 43, and >200 uM, respectively) and inhibits calcium mobilization induced by carbamoylcholine in SK-N-SH cells (IC50= 28 uM), as well as in primary rat bladder smooth muscle cells.1Migrastatin inhibits the migration of EC17 esophageal cancer cells in a wound healing assay (IC50= 10 ug/ml) and 4T1 mouse mammary carcinoma cells in a chamber cell migration assay (IC50= 29 uM).2It enhances cytotoxicity induced by vinblastine in vincristine-resistant P388/VCR cells.3