Figure 8. Protein levels of regulators related to iron transport (NRAMP2, Natural resistance associated macrophage protein 2) and iron storage (ferritin) are decreased while expression of proteins participating in non transferrin bound iron (NTBI) uptake (ZIP14, Zinc importer protein 14) and iron export (ferroportin) does not differ in tumor-initiating cells (TICs).

Protein levels of NRAMP2 (A), ferritin (B), zinc transporter protein 14 (C) and ferroportin (D) in the MCF-7 cell line (CTRL) and MCF-7 derived spheres (SPH) are shown. The protein expression was quantified by the image J software from 2 to 5 independent samples, standard error is SEM, p-values lower than 0.05 are denoted with a star and were calculated and plotted in GraphPad prism, using the unpaired t-test.