Evaluation of tellurium toxicity in transformed and non-transformed human colon cells.
Diphenyl ditelluride (DPDT) and tellurium tetrachloride (TeCl(4)) were evaluated for toxicity in transformed (HT-29, Caco-2) and non-transformed colon cells (CCD-18Co). Significant decreases in viability were observed with DPDT exposure in HT-29 (62.5-1000 μM), Caco-2 (31.25-1000 μM) and CCD-18Co cells (500-1000 μM) and with TeCl(4) in HT-29 (31.25-1000 μM), Caco-2 (31.25-1000 μM) and CCD-18Co cells (500-1000 μM). Light microscopy confirmed viability analysis. Significant increases in caspase 3/7 and 9 activity were observed with DPDT in HT-29 (500-1000 μM) and CCD-18Co cells (1000 μM) indicating apoptosis. No significant increases in caspases were seen with TeCl(4) indicating necrosis. Apoptosis or necrosis was confirmed with fluorescent staining (FITC-Annexin, Hoechst 33342 and Ethidium Homodimer). Significant decreases in GSH/GSSG ratio were observed with DPDT in HT-29 (62.5-1000 μM), and CCD-18Co cells (1000 μM) and with TeCl(4) in HT-29 (62.5-1000 μM) and CCD-18Co cells (250-1000 μM). We concluded that cells treated with DPDT resulted in apoptosis and TeCl(4) treatment in necrosis. GSH/GSSG ratio shifts indicate oxidative mechanisms are involved.
Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St John's University, Queens, NY 11439, USA.
Puneet
P
Vij
Diane
D
Hardej
D001555:Benzene Derivatives / Q000633:toxicity; D018938:Caco-2 Cells; D020169:Caspases / Q000378:metabolism; D002471:Cell Transformation, Neoplastic / Q000187:drug effects*; D019073:HT29 Cells; D015386:Hazardous Substances / Q000633:toxicity*; D006801:Humans; D009942:Organometallic Compounds / Q000633:toxicity; D013691:Tellurium / Q000633:toxicity*
D001555:Benzene Derivatives; D015386:Hazardous Substances; D009942:Organometallic Compounds; C434247:diphenylditelluride; C036605:tellurium tetrachloride; D020169:Caspases; D013691:Tellurium