Mifepristone, 1 g

A small molecule from STEMCELL Technologies described as a progesterone and glucocorticoid receptor antagonist (Ki = 0.64 and 0.1 nM, respectively; Attardi et al.; Song et al.; von Geldern et al.). The compound is also referred to by the alternative name RU-486 and has a reported molecular weight of 429.6 g/mol with a purity of ≥ 98%. It is supplied as a crystalline solid, stable at -20°C as supplied, and should be protected from prolonged exposure to light; for long-term storage, it should be kept with a desiccant. The product remains stable as supplied for 12 months from the date of receipt.

It has been cited in the literature in connection with the treatment of leiomyomata, endometriosis, breast cancer, and meningioma (Mahajan et al.). Reported solubility values are DMSO ≤ 45 mM and absolute ethanol ≤ 45 mM. As a guide, a 10 mM stock solution in DMSO can be prepared by resuspending 10 mg in 2.33 mL of DMSO. The compound has low solubility in aqueous media, so when used as a cell culture supplement, stock solutions should be diluted into culture medium immediately before use, with final DMSO concentration kept below 0.1% to avoid potential cell toxicity. Published research applications include inhibition of cyclin-dependent kinase 1 (CDK1) and cyclin-dependent kinase 2 (CDK2) expression, leading to cell cycle arrest and apoptosis in endometrial epithelial and stromal cells in adenomyosis (Che et al.), and induction of cell cycle arrest and apoptosis in antiestrogen-resistant breast cancer cells in vitro (Gaddy et al.). The product is for research use only and is not intended for human or animal diagnostic or therapeutic uses.