Expression of BAX in cell nucleus after experimentally induced apoptosis revealed by immunogold and embedment-free electron microscopy.
The unique combination of immunocytochemistry with embedment-free electron microscopy was applied for precise and specific localisation of BAX in the human colon adenocarcinoma COLO 205 cell line stimulated to undergo apoptosis by camptothecin (DNA topoisomerase I inhibitor). Camptothecin-induced apoptosis was associated with redistribution of BAX from cytosol to organelle membranes: mitochondria, Golgi apparatus, endoplasmic reticulum and via nuclear envelope pores to the nucleus, occurring within 60-180 min of cell exposure to the drug. An increase in BAX immunoreactivity on fine filaments and the lamina-pore complex of the nuclear matrix was also observed. The increase in BAX expression in the nuclear area of camptothecin-treated COLO 205 cells was confirmed by quantitative analysis using laser scanning cytometry. The subcellular translocations of BAX preceded the appearance of any morphological symptoms of apoptosis.
Gajkowska
B
B
Laboratory of Cell Ultrastructure, Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland. gajk@cmdik.pan.pl
Motyl
T
T
Olszewska-Badarczuk
H
H
Godlewski
M M
MM
D017209:Apoptosis / Q000187:drug effects; D002166:Camptothecin / Q000494:pharmacology; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D003593:Cytoplasm / Q000378:metabolism / Q000648:ultrastructure; D004721:Endoplasmic Reticulum / Q000378:metabolism / Q000648:ultrastructure; D005434:Flow Cytometry / Q000379:methods; D006056:Golgi Apparatus / Q000378:metabolism / Q000648:ultrastructure; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism / Q000648:ultrastructure; D008854:Microscopy, Electron / Q000379:methods; D016253:Microscopy, Immunoelectron; D008928:Mitochondria / Q000378:metabolism / Q000648:ultrastructure; D009685:Nuclear Envelope / Q000378:metabolism / Q000648:ultrastructure; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis*; D019253:Proto-Oncogene Proteins c-bcl-2; D059004:Topoisomerase I Inhibitors; D014407:Tumor Cells, Cultured; D051028:bcl-2-Associated X Protein
C494826:BAX protein, human; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D059004:Topoisomerase I Inhibitors; D051028:bcl-2-Associated X Protein; D002166:Camptothecin