RESUMEN
Racemic resolution of (+/-)-MAD28, a representative caged xanthone, was accomplished using (1S, 4R)-(-)-camphanic chloride as the chiral agent. Selective crystallization of the resulting diastereomers in acetonitrile produced, after hydrolysis, the pure enantiomers. Screening of racemic MAD28 and both enantiomers across a broad spectrum of breast cancer cell lines revealed that they: (a) are equipotent in each of the breast cancer subtypes examined; and (b) exhibit a higher degree of cytotoxicity against breast cancer cell lines of basal-like subtype and triple negative receptor status. The results support the notion that MAD28 and related caged xanthones are promising drug leads against chemoresistant and metastatic cancers.
Asunto(s)
Antineoplásicos/química , Xantonas/química , Antineoplásicos/síntesis química , Antineoplásicos/farmacología , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Cristalografía por Rayos X , Ensayos de Selección de Medicamentos Antitumorales , Femenino , Humanos , Conformación Molecular , Estereoisomerismo , Xantonas/síntesis química , Xantonas/farmacologíaRESUMEN
Inflammatory breast cancer (IBC) is a highly metastatic, lethal form of breast cancer that lacks targeted therapeutic strategies. Inspired by the promising cytotoxicity of gambogic acid and related caged xanthones in spheroidsMARY-X, an in vitro preclinical IBC model, we constructed a library of synthetic analogs and performed structure-activity relationship studies. The studies revealed that functionalizing the A-ring of the caged xanthone framework can significantly affect potency. Specifically, introduction of hydroxyl or fluorine groups at discrete positions of the A-ring leads to enhanced cytotoxicity at submicromolar concentrations. These compounds induce complete dissolution of spheroidsMARY-X with subsequent apoptosis of both the peripherally- and centrally-located cells, proliferative and quiescent-prone (e.g. hypoxic), respectively. These results highlight the structural flexibility and pharmacological potential of the caged xanthone motif for the design of IBC-targeting therapeutics.