Fig. 2

Ferumoxytol and NK cells synergistically induce ferroptosis in PC3 prostate cancer and the ferumoxytol mediated ferroptosis activates the cytotoxic function of NK cells. A. Confocal images of C11-BODIPY stained PC3 cells showed lipid peroxidation status. PC3 cells were treated with Ferumoxytol and co-cultured with NK-92MI cells (green). (scale bar = 20 µm) B. Fluorescent level of intracellular LPO in PC3 cells treated with each group was measured by flow cytometry. C. NK cell-mediated tumor cell killing effect of each treatment (ferumoxytol, NK-92MI, and ferumoxytol + NK-92MI) was determined by CFSE/7AAD assay. Ferrostatin-1 ferroptosis inhibitor was used to confirm the ferroptosis enhanced NK cell killing efficacy of the co-treatment ferumoxytol + NK-92MI. D. Interferon gamma secretion in only NK cell treatment and ferumoxytol + NK cell treatment. E. Degranulation of NK-92MI cells was determined by analysis of CD107a expression on NK cells. NK-92MI and PC3 cells were co-cultured at a 10:1 effector: target ratio and measured by flow cytometry. The data represent mean ± s.d. (n = 3) and statistical significance was analyzed by two-tailed Student’s t-tests. *P < 0.05, **P < 0.01, and ****P < 0.0001