ABC294640 markedly alters the ratio of ceramide/S1P consistent with inhibition of SK activity in MDA-MB-231 cells. ABC294640 inhibits tumor cell proliferation with IC50 values ranging from approximately 6 to 48 μM, and impairs tumor cell migration concomitant with loss of microfilaments. ABC294640 induces nonapoptotic cell death, morphological changes in lysosomes, formation of autophagosomes, and increases in acidic vesicles in A-498, PC-3, and MDA-MB-231 cells. In both MCF-7 and ER-transfected HEK293 cells, ABC294640 decreases E2-stimulated ERE-luciferase activity.
In vivo
In mice bearing mammary adenocarcinoma xenografts, ABC294640 (100 mg/kg, p.o.) significantly reduce tumor growth, associated with depletion of S1P levels. In severe combined immunodeficient mice bearing A-498 xenografts, ABC294640 delays tumor growth and elevates autophagy markers. ABC294640 protects against liver transplantation-induced inflammation and cross-talk between innate and adaptive immunities, major events precipitating and exacerbating graft injury, and improves liver function and survival.