AIM: To study the effects of disulfiram/copper complex (DSF/Cu) on ultrastructures and mechan-ical properties of human breast cancer and normal breast epithelial cells by atomic force microscopy (AFM) based on the nanoscale resolution and piconewton force measurement level.METHODS: The change of cell cycle and apoptotic rate of MCF-7 cells and MCF-10A cells induced by DSF/Cu were compared by flow cytometry.The cell surface morphology, ultra-structure, height, width and roughness were detected by AFM.The effects of DSF/Cu on the hardness (Young’s modu-lus) of the 2 kinds of cells were determined by AFM with indentation technique.RESULTS: DSF/Cu significantly in-duced apoptosis of the MCF-7 cells in a dose-dependent manner, whereas had little effect on the MCF-10A cells.The cell cycle analysis showed that DSF/Cu induced G2 /M arrest in the MCF-7 cells, but led to G0 /G1 arrest in the MCF-10A cells.The AFM images showed that the MCF-7 cells shrank and showed smaller and smoother morphology, and the filopo-dia were retracted obviously, even some became into lamellipodia, or disappeared completely after treated with DSF/Cu at concentrations of 400 and 800 nmol/L.The quantitative analysis indicated that the MCF-7 cells showed smaller width and
larger height, and the root mean square roughness and average roughness were decreased significantly in a dose-dependent manner after treated with DSF/Cu at concentrations of 400 and 800 nmol/L.However, little effect in the MCF-10A cells was observed.The biomechanics test at a single cell level demonstrated that the Young’s modulus of the MCF-7 cells and MCF-10A cells were both increased, yet the proportion increased in the MCF-7 cells was much higher than that in the MCF-10A cells after treated with DSF/Cu at concentrations of 400 and 800 nmol/L.CONCLUSION: DSF/Cu has strong antitumor effect on breast cancer with high efficiency and low toxicity by changing the properties of the biomechanics specifically.

Aim To explore the effects and mecha-nisms of choro-oxime derivatives on spatial learning and memory impairment in Kunming mice and SD rats induced by scopolamine and Aβ1-42 , respectively. Methods 40 Kunming mice were randomly divided into 5 groups: control group, model group, donepezil treatment group, arimoclomol treatment group and TCO-2 treatment group. There were 8 mice in each group. Mice of control group were established by intra-peritoneal injection of saline, and mice of other groups were injected with scopolamine and caused memory im-pairment. Both control group and model group were treated with solvent by intraperitoneal administration;donepezil treatment group received donepezil by intra-gastric administration; arimoclomol treatment group and TCO-2 treatment group were given the correspond-ing drugs by abdominal injection, respectively. The solvent and drugs were given at the same time every morning for 8 days. Spatial learning and memory abili-ty were tested by Morris water maze from the fifth day of the drugs administration. 40 SD rats were divided into 5 groups the same as the dementia model men-tioned above. Mice of control group were established by intracerebroventricular injection of saline, and mice of other groups were injected with insoluble Aβ1-42 to be induced of memory impairment. Solvent and drugs were also delivered as mentioned above. Morris water maze was carried out from the fifth day of the drug de-livery. After that, acetyl cholinesterase activity of hip-pocampus was tested with acetyl cholinesterase reagent kit; the content of Aβ1-42 in hippocampus was meas-ured by ELISA assay kit;the expression of phosphoryl-ated tau proteins was detected by Western Blot. Re-sults In both two dementia models, choro-oxime de-rivatives could improve the spatial learning and memory ability, shorten the escape latency and increase the times of crossing the former platform. Choro-oxime de-rivatives could also inhibit the acetyl cholinesterase ac-tivity in animal brain, decrease the concentration of Aβ1-42 and the expression of phosphorylated tau pro-teins in the dementia rats’ hippocampus. Conclusions Spatial learning and memory deficits induced by sco-polamine and Aβ1-42 could be reversed by choro-oxime derivatives. It may be concerned with enhancement of the cholinergic system functions and reduction of the levels of Aβ1-42 and phosphorylated tau proteins in the brain.

Aim To study the mechanism of DSF-Cu induced apoptosis of human nasopharyngeal carcinoma CNE-2 Z cells by affecting the function of mitochondria and cytoskeleton. Methods The cell cycle,the rate of apotosis,the levels of intracellular ROS and MMP in CNE-2 Z cells were tested by flow cytometry after trea-ted with different concentration of DSF-Cu. The chan-ges of the cell surface morphology, ultrastructure, cell height, width and roughness were detected by AFM. The distribution and reorganization of cytoskeleton F-actin were observed by Laser scanning confocal micro-scope. Results Cells were incubated with different concentration of DSF-Cu ( 0 ~200 nmol · L-1 ) for 24 h, the apoptotic ratio increased significantly and the treatment of DSF-Cu resulted in a concentration-de-pendent accumulation of CNE-2Z cells in G2/M phase. Furthermore,the treatment of DSF-Cu was able to in-crease the production of intracellular ROS and decrease the MMP in CNE-2Z cells. In addition,AFM imaging showed that compared to the control group,with the in-crease of DSF-Cu concentration,the CNE-2Z cells be-came smaller, cytoplasm condensed, the height in-creased,and the surface roughness reduced. Moreover, the filopodia became shorter, shrinked and even com-pletely destroyed after treated with different concentra-tion of DSF-Cu. At last,the LSCM image showed that the fluorescence intensity of F-actin networks was de-creased, then the structure was rearranged and de-stroyed obviously by treated with DSF-Cu. Conclusion DSF-Cu can induce apoptosis and arrest cell cycle at G2/M phase in CNE-2Z cell through a mitochondria-dependent pathway. Above findings highlight the appli-cations of AFM at the single cell level for the investiga-tion of antineoplastic drug in nasopharyngeal carcinoma therapy.