assessment of cr(vi)-induced cytotoxicity and genotoxicity using high content analysis铬(vi)的评估全身的细胞毒性和基因毒性使用高含量分析.pdf

Assessment of Cr(VI)-Induced Cytotoxicity and Genotoxicity Using High Content Analysis 1 2 2 3 3 1 Chad M. Thompson *, Yuriy Fedorov , Daniel D. Brown , Mina Suh , Deborah M. Proctor , Liz Kuriakose , Laurie C. Haws4, Mark A. Harris1 1ToxStrategies, Katy, Texas, United States of America, 2 Thermo Fisher Scientific, Pittsburgh, Pennsylvania, United States of America, 3 ToxStrategies, Austin, Texas, United States of America, 4 ToxStrategies, Rancho Santa Margarita, California, United States of America Abstract Oral exposure to high concentrations of hexavalent chromium [Cr(VI)] induces intestinal redox changes, villus cytotoxicity, crypt hyperplasia, and intestinal tumors in mice. To assess the effects of Cr(VI) in a cell model relevant to the intestine, undifferentiated (proliferating) and differentiated (confluent) Caco-2 cells were treated with Cr(VI), hydrogen peroxide or rotenone for 2–24 hours. DNA damage was then assessed by nuclear staining intensity of 8-hydroxydeoxyguanosine (8- OHdG) and phosphorylated histone variant H2AX (c-H2AX) measured by high content analysis methods. In undifferentiated Caco-2, all three chemicals increased 8-OHdG and c-H2AX staining at cytotoxic concentrations, whereas only 8-OHdG was elevated at non-cytotoxic concentrations at 24 hr. Differentiated Caco-2 were more resistant to cytotoxicity and DNA damage than undifferentiated cells, and there were no changes in apoptotic markers p53 or annexin-V. However, Cr(VI) induced a dose-dependent translocation of the unfolded protein response transcription factor ATF6 into the nucleus. Micronucleus (MN) formation was assessed in CHO-K1 and A549 cell lines. Cr(VI) increased MN frequency in CHO-K1 only at