Fig. 1.

Glutaminolysis mediates cystine deprivation-induced ferroptosis. (A, B) Ferroptotic cell death induced by cystine (CC) deprivation in head and neck cancer (HNC) cells. Propidium iodide (PI)-positive cells were stained and counted using fluorescent microscopy and flow cytometry after cystine deprivation for 48 h. (C, D) Pharmacological inhibition of glutaminolysis pathway abrogating ferroptotic cell death. (E) Schematic summary of the glutaminolysis pathway and tricarboxylic acid (TCA) cycle. (F) α-ketoglutarate (αKG) mimicking ferroptotic cell death mediated by glutaminolysis. Four millimolar αKG was added to the media with or without 20 μM Compound 968 or 0.5 mM AOA. Scale bar, 50 μm **P < 0.001. NS indicates statistically not significant.