Study On The Mechanism Of Iron Uptake In Aggressive Breast Cancer Cells Under DFD-induced Iron Deficient Condition

Trace element iron can contribute to tumor initiation,tumor growth and tumor metastasis.Deferoxamine(DFO),a widely used iron chelator,normally is used for the treatment of iron-overload disease,including some types of cancer.Recently,it has been suggested that iron chelator DFO can increase intracellular iron levels in aggressive human breast cells,leading promoted the migration of breast cancer cells and contributed to the development of advanced malignancy.However,the mechanism of the DFO-induced increasing iron uptake in the aggressive breast cancer cells was still remained unexplained.In order to investigate the pathway of iron uptake in aggressive breast cancer cells under DFO-induced iron deficient condition,we chose aggressive human breast cancer MDA-MB-231,Hs578 T and BT549 cells and no-aggressive breast cancer MCF-7 and T47 D cells.We used Western Blotting and cell immunofluorescence to detect the iron related protein and found that after DFO treatment,the iron-related protein levels increased significantly in aggressive human breast cancer as compared tothe control.Our results also found that under DFO-induced iron-deficient condition,both Tf R1 and DMT1 expressed on cell membrane were involved in increasing intracellular iron uptake in MDA-MB-231,Hs578 T and BT549 cell lines,which were assessed by Western Blotting,neutralizing antibodies,co-incubation experience and transwell assay.And then We used q RT-PCR and ELISA to explore the levels of IL-6 in breast cancer cells and found that DFO treatment could promote autocrine secretion of IL-6 in aggressive MDA-MB-231 cells,while the levels of IL-6 was decreased in no-aggressive MCF-7 cell under DFO-induced iron deficient condition.Therefore,we neutralized the autocrine secretion of IL-6 of aggressive MDA-MB-231 cells to study the mechanism of iron uptake in aggressive breast cancer cells under DFO-induced iron deficiency.With addition of neutralizing antibody IL-6,we found that PI3K/AKT signaling pathway was suppressed and the iron-related protein levels were reduced,leading to decrease iron uptake in DFO-treated MDA-MB-231 cells.At the same time,PI3 K inhibitor can also reduce iron-related protein levels in MDA-MB-231 cells under DFO-induced iron deficiency.These results suggested that DFO treatment could activate IL-6/PI3K/AKT signaling in aggressive MDA-MB-231 breast cancer cells.Collectively,all these results identified that DFO treatment couldactivate IL-6/PI3K/AKT signaling to up-regulate the expression of iron-related proteins enhancing iron uptake in aggressive MDA-MB-231 breast cancer cells.In contrast,under DFO-induced iron deficiency could reduce the expression of iron-related protein in no-aggressive breast cancer cell.