國家衛生研究院 NHRI:Item 3990099045/2457
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    Please use this identifier to cite or link to this item: http://ir.nhri.org.tw/handle/3990099045/2457


    Title: 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induces oxidative stress, DNA strand breaks, and poly(ADP-ribose) polymerase-1 activation in human breast carcinoma cell lines
    Authors: Lin, PH;Lin, CH;Huang, CC;Chuang, MC;Lin, PP
    Contributors: Division of Environmental Health and Occupational Medicine
    Abstract: The formation of reactive oxygen species (ROS) plays a critical role in 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced toxicities in mammalian cells since it promotes cell proliferation, growth arrest, and apoptosis. In this study, we investigated whether TCDD induces oxidative stress and DNA damage in human ER alpha(+)/MCF-7 and ER alpha(-)/MDA-MB-231 breast cancer cells and whether this is accompanied by the initiation of DNA repair events. Results indicated that viability of MCF-7 and MDA-MB-231 cells was concentration- and time-dependently reduced by TCDD. Further, we observed significant increases in ROS formation and decreases in intracellular glutathione (GSH) in these two cell lines after TCDD treatment. Overall, the extent of cell death was greater in MCF-7 cells than in MDA-MB-231 cells whereas the magnitude of ROS formation and GSH depletion was greater in MDA-MB-231 cells than in MCF-7 cells. In addition, we observed that at non-cytotoxic concentration (1 nM for 5 h), TCDD induced decreases in intracellular NAD(P)H and NAD(+) in MCF-7 and MDA-MB-231 cells. These decreases were completely blocked by three types of poly(ADP-ribose) polymerase-1 (PARP-1) inhibitors. The catalytic activation of PARP- I in cells treated with TCDD was confirmed by detection of the presence of polymers of ADP-ribose-modified PARP- I using Western blotting. Moreover, we demonstrated increases in the number of DNA strand breaks in MCF-7 and MDA-MB-231 cells exposed to TCDD as measured by the single-cell gel electrophoresis (Comet) assay. Overall, this evidence confirms that TCDD induces decreases in intracellular NAD(P)H and NAD(+) through PARP-1 activation mediated by formation of DNA strand breaks. In addition, we demonstrated that the extent of oxidative stress and DNA damage was greater in MDA-MB-231 cells than in MCF-7 cells, with a strong correlation to estrogen receptor (ER) status. In conclusions, our findings add further support to the theme that ROS formation is a significant determinant factor in mediating the induction of oxidative DNA damage and repair in human breast cancer cells exposed to TCDD and that the TCDD-induced oxidative stress and DNA damage may, in part, contribute to TCDD-induced carcinogenesis. (C) 2007 Elsevier Ireland Ltd. All rights reserved.
    Keywords: Toxicology
    Date: 2007-08-10
    Relation: Toxicology Letters. 2007 Aug;172(3):146-158.
    Link to: http://dx.doi.org/10.1016/j.toxlet.2007.06.003
    JIF/Ranking 2023: http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=NHRI&SrcApp=NHRI_IR&KeyISSN=0378-4274&DestApp=IC2JCR
    Cited Times(WOS): https://www.webofscience.com/wos/woscc/full-record/WOS:000249214300006
    Cited Times(Scopus): http://www.scopus.com/inward/record.url?partnerID=HzOxMe3b&scp=34547559840
    Appears in Collections:[Pinpin Lin] Periodical Articles

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