Induction of Aneuploidy, Centrosome Abnormality, Multipolar Spindle, and Multipolar Division in Cultured Mammalian Cells Exposed to an Arsenic Metabolite, Dimethylarsinate

Cadmium promotes the binding and centrosomal translocation of CCDC85C and PLK4 via ROS-GCLM pathway to trigger centrosome amplification in colon cancer cells

Cadmium (Cd) is a prevalent heavy metal contaminant that can cause centrosome amplification (CA) and cancer. Since CA can initiate tumorigenesis, it is plausible that cadmium initiates tumorigenesis via CA. The present study investigated the signaling pathways underlying CA by Cd. Our findings confirmed that sub-toxic concentrations of Cd could induce CA in the HCT116 colon cancer cells, and revealed that reactive oxygen species (ROS), GCLM, CCDC85C and PLK4 were the signaling molecules that formed a pathway of ROS-GCLM-CCDC85C-PLK4. Cd not only increased the protein levels of CCDC85C and PLK4, but also promoted their distribution to the centrosomes. Molecular docking analysis revealed that CCDC85C and PLK4 had the binding potential. Indeed, antibodies against CCDC85C and PLK4 were able to pull down PLK4 and CCDC85C, respectively. Knockdown of CCDC85C decreased the Cd-promoted centrosomal distribution of PLK4. Similarly, knockdown of PLK4 reduced the centrosomal distribution of CCDC85C. Our results suggest that Cd activates ROS-GCLM pathway that triggers the expression of and binding between CCDC85C and PLK4, and promotes the translocation of CCDC85C-PLK4 complex to the centrosomes, which eventually leads to CA.

Effects of sodium arsenite and dimethyl arsenic acid on Liaoning cashmere goat skin fibroblasts

The morphology and oxidation state of arsenic in its compounds affects the skin cell toxicity. Accordingly, the present study was conducted to explore the effects of two different arsenic compounds on the proliferation and survival of Liaoning cashmere goat skin fibroblasts. Based on MTT assay results, at 24 h, the proliferation concentration, critical concentration, and half inhibitory concentration (IC50) of sodium arsenite were 0.50, 5.00, and 45.66 μmol/L, respectively. The corresponding values for dimethyl arsenic acid were 0.85, 1.00, and 38.68 mmol/L. Immunofluorescence, transmission electron microscopy, and mitochondria membrane potential (MMP) assays showed that sodium arsenite promotes microtubule polymerization and increases MMP, while cells treated with dimethyl arsenic acid exhibited cytoskeletal collapse and decreased MMP. In the IC50 groups for both arsenic agents, the cytoskeletons collapsed, microtubules were gathered into bundles, and MMP was significantly decreased. Dimethyl arsenic acid had a stronger effect on MMP than sodium arsenite. Flow cytometry revealed a slightly lower occurrence of apoptosis in the sodium arsenite proliferation group, while it was slightly increased in the dimethyl arsenic acid proliferation group. Apoptosis was increased more significantly in the sodium arsenite IC50 group than in the dimethyl arsenic acid IC50 group. These results indicate that the differences in cell proliferation and cytotoxicity induced by inorganic and organic arsenic are related to their effects on cellular structures.