Anti-tumor Effects And Its Mechanisms Of Iron(iii) Complexe Of 2-acetylpyrazine N(4)-methylthiosemicarbazone

Objective: To investigate the potent inhibitor of an iron complex of 2-acetylpyrazine N(4)-methylthiosemicarbazone(HL-iron) on the K562(a human leucocythemia cancer cell line) cells, in a dose- and time-dependent manner.Methods: Different dose of HL-iron was used to induce the cytotoxicity in K562 cells in order to optimize dose by MTT assay. The enzyme activity of superoxide dismutase(SOD), glutathione peroxidase(GSH-PX) and the lipid peroxidation products malondialdehyde(MDA) in the cells were observed. DNA-binding dye Acridine Orange/ Ethidium Bromide (AO/EB) was used to determine the morphological characteristic of apoptotic cells. Mitochondrial membrane potential in K562 cells were monitored by the high content screening (HCS) combining with Rh123. PI was used to a signature of cell membrane integrity and cell damage .Fura-2/AM was employed to detect intracellular Ca2+ concentration([Ca2+]i) as a cell permeable fluorescent probe.Results: 1. After treatment with 1μM,10μM,30μM,50μM HL-iron in K562 cells for 48 hours, the cell viability decreased markedly, while at concentration (0.1μM) could inhibit the cell viability obviously. 2. The results suggest that HL-iron decreased SOD and GSH-PX activity, in contrast, HL-iron increased MDA and ROS. 3. After the treatment with HL-iron, the mitochondrial membrane potential significantly decreased while intracellular Ca2+ increased, and microscopic observation showed that K562 cells exhibited morphological alterations such as cell shrinkage and membrane blabbing, the typical characteristics of apoptotic cell death.Conclusions:1. 1μM,10μM,30μM preaggregated HL-iron could induce toxicity, oxidative damage and apoptosis in addition to overload of Ca2+ in K562 cells, which result in the cell death ultimately. 2. The study shows that HL-iron at the different concentration has a induced effects of cytotoxicity and apoptosis in K562 cells, which may represent the cellular mechanisms including increasing ROS, degrading SOD and GSH-PX activity,inducing the cell apoptosis and overload of Ca2+ in K562 cells. HL-iron may also represent a potential treatment strategy for anti-tumor.