Abstract
The utility of dominant acting proapoptotic molecules to induce cell death in cancer cells is being evaluated in preclinical studies and clinical trials. We recently developed a binary adenoviral expression system to enable the efficient gene transfer of Bax and other proapoptotic molecules. Using this system, overexpression of Bax protein in four non-small-cell lung cancer (NSCLC) cell lines, H1299, A549, H226 and H322, was evaluated. The H322 line exhibited significant resistance to Bax-induced cell death compared to the other cell lines. H322 cells had the highest level of glutathione (GSH). GSH levels were significantly decreased following buthionine sulfoximine treatment and this coincided with enhanced apoptosis induction by Ad-Bax in H322 cells. GSH depletion enhanced Bax protein translocation to mitochondrial membranes. These findings suggest that the redox status may be a determinant of Bax-mediated cell death and that manipulation of intracellular thiols may sensitize cells to apoptosis by facilitating Bax insertion into mitochondrial membranes.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Adenoviridae / genetics
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Apoptosis* / drug effects
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Biological Assay
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Buthionine Sulfoximine / pharmacology
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Carcinoma, Non-Small-Cell Lung / metabolism
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Carcinoma, Non-Small-Cell Lung / pathology
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Carcinoma, Non-Small-Cell Lung / therapy*
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Caspase 3
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Caspases / metabolism
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Cell Line, Tumor
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Combined Modality Therapy
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Cytochromes c / metabolism
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Deoxyribonucleases / metabolism
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Gene Transfer Techniques
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Genes, bcl-2 / genetics
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Genetic Vectors / genetics
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Glutathione / analysis
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Glutathione / metabolism*
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Humans
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Lung Neoplasms / metabolism
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Lung Neoplasms / pathology
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Lung Neoplasms / therapy*
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Mitochondria / metabolism
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Oxidation-Reduction
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Poly-ADP-Ribose Binding Proteins
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Proto-Oncogene Proteins c-bcl-2 / genetics*
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Proto-Oncogene Proteins c-bcl-2 / metabolism
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bcl-2-Associated X Protein
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bcl-X Protein
Substances
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BAX protein, human
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BCL2L1 protein, human
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Poly-ADP-Ribose Binding Proteins
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Proto-Oncogene Proteins c-bcl-2
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bcl-2-Associated X Protein
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bcl-X Protein
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Buthionine Sulfoximine
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Cytochromes c
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DFFB protein, human
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Deoxyribonucleases
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CASP3 protein, human
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Caspase 3
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Caspases
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Glutathione