MNPs-Fe₃O₄mediates malignant Hematolpoectic cell apoptosis

This study was purposed to evaluate whether the safe concentration of magnetic nanoparticles of Fe₃O₄(MNPs-Fe₃O₄) for monocytes could induce the SKM-1 cell apoptosis. The average size and Zeta potential of MNPs-Fe₃O₄were determined by transmission electron microscopy and the Malvern Zetasizer 3000 HS, respectively. The cell viability after being exposed to MNPs-Fe₃O₄for 12, 24, 48, and 72 hours was detected by using cell count Kit-8. The cell apoptosis was evaluated by flow cytometry with Annexin V/PI double staining and Wright-Giemsa staining. The cell cycle was measured by flow cytometry. The levels of active caspase-3, survivin and bcl-rambo in cells treated with MNPs-Fe₃O₄and/or trolox for 48 hours were detected with Western blot. The results showed that the cell viability decreased in SKM-1 cells after exposure to 50 µmol/L and 100 µmol/L MNPs-Fe₃O₄(P < 0.05), but did not in monocytes (P > 0.05), compared with that of each non-MNPs-Fe₃O₄-treated group. This exposure also induced the SKM-1 cells to be arrested in G0/G1. Annexin V/PI staining assay showed that cell apoptotic rate induced by 100 µmol/L MNPs-Fe₃O₄was significantly high in SKM-1 cells while not so high in monocytes, and the pretreatment with trolox could attenuate the apoptosis. Moreover, the active caspase-3 increased in SKM-1 cells after the exposure to MNPs-Fe₃O₄, while that was not in monocytes, and the increased expression of BCL-rambo and the decreased expression of survivin involved in the process were also observed. It is concluded that MNPs-Fe₃O₄can induce the caspase 3-dependent SKM-1 cell apoptosis by increasing the BCL-rambo expression and decreasing the survivin expression, but this cytotoxic effect can not be observed in monocyte's.