Characterization of the cellular response during apoptosis induction in cadmium-treated Hep G2 human hepatoma cells.
Cadmium is a toxic transition heavy metal of continuing occupational and environmental concern, with a wide variety of adverse effects on regulation of gene expression and cellular signal transduction pathways. Injury to cells by cadmium leads to a complex series of events that can culminate in the death of the cell. It has been reported that cadmium induces apoptosis in many cell lines. However, the morphological characteristics leading to apoptosis or subsequent regeneration in cells exposed to cadmium have not been clarified. We evaluated whether human hepatoma cells maintained in culture undergo apoptosis when exposed to cadmium. Cytotoxic activity of cadmium on Hep G2 cells determined using 3-[4,5-dimethylthiazol-2-yl]-2,5- diphenyltetrazolium bromide assay. A DNA ladder assay was performed by electrophoresis. Cell cycle analysis was quantified by flow cytometry. Nuclear morphology was studied by fluorescence microscopy after staining with propidium iodide and Hoechst 33342. Morphologic alterations in culture hepatocytes treated with CdCl2 were observed by transmission electron microscopy. We have demonstrated that apoptosis is a major mode of elimination of damaged HepG2 cells in cadmium toxicity and it precedes necrosis.
Aydin
Hikmet Hakan
HH
Department of Biochemistry, Ege University School of Medicine, Ege University Bornova, TR-35100 Izmir, Turkey.
Celik
Handan Ak
HA
Deveci
Remziye
R
Terzioglu
Ender
E
Karacali
Sabire
S
Mete
Nihal
N
Akarca
Ulus
U
Batur
Yücel
Y
D017209:Apoptosis / Q000187:drug effects*; D002104:Cadmium / Q000494:pharmacology* / Q000633:toxicity; D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000473:pathology*; D002453:Cell Cycle / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D053938:DNA Fragmentation / Q000187:drug effects; D005453:Fluorescence; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics / Q000473:pathology*; D008854:Microscopy, Electron
D002104:Cadmium