caa a22 4500 445852720 CHVBK 20180317145418.0 cr unu---uuuuu 170323e20110601xx s 000 0 eng 10.1007/s00204-011-0710-5 doi (NATIONALLICENCE)springer-10.1007/s00204-011-0710-5 Analysis of arsenic metabolites in HepG2 and AS3MT-transfected cells [Elektronische Daten] [Takayuki Watanabe, Yuki Ohta, Ayano Mizumura, Yayoi Kobayashi, Seishiro Hirano] It has been suggested that arsenic (+3 oxidation state) methyltransferase (AS3MT) plays a critical role in methylation of arsenic, and that arsenic-glutathione conjugate is a substrate for AS3MT-catalyzed methylation of arsenic. However, the mechanism of arsenic methylation in cells is not fully understood. Here, we have constructed T-REx-CHO-hAS3MTtr cells that transiently overexpress human AS3MT in response to tetracycline. The decreases in cell viability after exposure to sodium arsenite were greater in tetracycline-treated cells (tet(+) cells) than in untreated cells (tet(−) cells). Concentration of total cellular arsenic was significantly higher in tet(+) cells than in tet(−) cells. Speciation analyses of arsenic metabolites in whole cell lysates and cell culture medium were performed using both HepG2 cells and T-REx-CHO-hAS3MTtr cells. Speciation analyses of arsenic metabolites in lysates of T-REx-CHO-hAS3MTtr cells revealed that dimethylated arsenicals were the predominant arsenic metabolites in tet(+) cells, while methylated metabolites were not found in tet(−) cells. In contrast, less amount of methylated arsenic metabolites were found in the HepG2 cell lysates, and monomethylated trivalent arsenicals were the predominant methylated arsenic metabolites. Arsenate was found in the culture medium after 24h culture with arsenite. A larger amount of arsenate was found in the culture medium of tet(+) or tet(−) cells compared to HepG2 cells. These findings indicated that AS3MT expression enhanced the cytotoxic effect of arsenite in tet(+) cells because these cells accumulated more arsenic metabolites than did the tet(−) cells, and accordingly, the tet(+) cells were more susceptible to arsenic than were the tet(−) cells. Oxidation-reduction of arsenic may be implicated in the toxic effects of arsenite. Springer-Verlag, 2011 Arsenic nationallicence Glutathione nationallicence AS3MT nationallicence Metabolite speciation nationallicence ICP-MS nationallicence Watanabe Takayuki Graduate School of Pharmaceutical Sciences, Chiba University, 263-8522, Yayoi, Inage, Chiba, Japan aut Ohta Yuki Research Center for Environmental Risk, National Institute for Environmental Studies, 16-2 Onogawa, 305-8506, Tsukuba, Ibaraki, Japan aut Mizumura Ayano Graduate School of Pharmaceutical Sciences, Chiba University, 263-8522, Yayoi, Inage, Chiba, Japan aut Kobayashi Yayoi Graduate School of Pharmaceutical Sciences, Chiba University, 263-8522, Yayoi, Inage, Chiba, Japan aut Hirano Seishiro Graduate School of Pharmaceutical Sciences, Chiba University, 263-8522, Yayoi, Inage, Chiba, Japan aut Archives of Toxicology Springer-Verlag 85/6(2011-06-01), 577-588 0340-5761 85:6<577 2011 85 204 https://doi.org/10.1007/s00204-011-0710-5 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00204-011-0710-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Watanabe Takayuki Graduate School of Pharmaceutical Sciences, Chiba University, 263-8522, Yayoi, Inage, Chiba, Japan aut NATIONALLICENCE 700 1- Ohta Yuki Research Center for Environmental Risk, National Institute for Environmental Studies, 16-2 Onogawa, 305-8506, Tsukuba, Ibaraki, Japan aut NATIONALLICENCE 700 1- Mizumura Ayano Graduate School of Pharmaceutical Sciences, Chiba University, 263-8522, Yayoi, Inage, Chiba, Japan aut NATIONALLICENCE 700 1- Kobayashi Yayoi Graduate School of Pharmaceutical Sciences, Chiba University, 263-8522, Yayoi, Inage, Chiba, Japan aut NATIONALLICENCE 700 1- Hirano Seishiro Graduate School of Pharmaceutical Sciences, Chiba University, 263-8522, Yayoi, Inage, Chiba, Japan aut NATIONALLICENCE 773 0- Archives of Toxicology Springer-Verlag 85/6(2011-06-01), 577-588 0340-5761 85:6<577 2011 85 204 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer