Abstract
Pretreatment of HepG2 and H1299 cells with chloramphenicol rendered the cells resistant to mitomycin-induced apoptosis. Both mitomycin-induced caspase 3 activity and PARP activation were also inhibited. The mitochondrial DNA-encoded Cox I protein, but not nuclear-encoded proteins, was down-regulated in chloramphenicol-treated cells. Cellular levels of the p21(waf1/cip1) protein and p21(waf1/cip1) mRNA were increased through a p53-independent pathway, possibly because of the stabilization of p21(waf1/cip1) mRNA in chloramphenicol-treated cells. The p21(waf1/cip1) was redistributed from the perinuclear region to the cytoplasm and co-localized with mitochondrial marker protein. Several morphological changes and activation of the senescence-associated biomarker, SA beta-galactosidase, were observed in these cells. Both p21(waf1/cip1) antisense and small interfering RNA could restore apoptotic-associated caspase 3 activity, PARP activation, and sensitivity to mitomycin-induced apoptosis. Similar effects were seen with other antibiotics that inhibit mitochondrial translation, including minocycline, doxycycline, and clindamycin. These findings suggested that mitochondrial stress causes resistance to apoptosis through a p21-dependent pathway.
MeSH terms
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Anti-Bacterial Agents / pharmacology
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Apoptosis*
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Biomarkers / metabolism
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Blotting, Western
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Caspase 3
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Caspases / metabolism
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Cell Cycle Proteins / genetics
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Cell Cycle Proteins / metabolism
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Cell Cycle Proteins / physiology*
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Cell Line, Tumor
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Cell Nucleus / metabolism
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Cellular Senescence
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Chloramphenicol / pharmacology*
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Clindamycin / pharmacology
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Cyclin-Dependent Kinase Inhibitor p21
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Cyclooxygenase 1
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Cytochromes c / metabolism
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Cytoplasm / metabolism
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DNA / chemistry
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DNA Damage
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DNA, Complementary / metabolism
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Down-Regulation
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Doxycycline / pharmacology
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Enzyme Activation
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Enzyme Inhibitors / pharmacology
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G1 Phase
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Genes, Reporter
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Humans
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Membrane Potentials
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Membrane Proteins
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Microscopy, Fluorescence
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Minocycline / pharmacology
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Mitochondria / enzymology
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Mitochondria / metabolism
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Mitochondria / pathology*
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Mitomycin / pharmacology
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Oligonucleotides, Antisense / chemistry
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Plasmids / metabolism
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Poly(ADP-ribose) Polymerases / metabolism
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Promoter Regions, Genetic
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Prostaglandin-Endoperoxide Synthases / metabolism
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Protein Biosynthesis
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Protein Synthesis Inhibitors / pharmacology*
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RNA / metabolism
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RNA, Messenger / metabolism
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RNA, Small Interfering / metabolism
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Reverse Transcriptase Polymerase Chain Reaction
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Ribosomes / chemistry
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Transfection
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Tumor Suppressor Protein p53 / metabolism
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beta-Galactosidase / metabolism
Substances
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Anti-Bacterial Agents
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Biomarkers
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CDKN1A protein, human
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Cell Cycle Proteins
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Cyclin-Dependent Kinase Inhibitor p21
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DNA, Complementary
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Enzyme Inhibitors
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Membrane Proteins
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Oligonucleotides, Antisense
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Protein Synthesis Inhibitors
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RNA, Messenger
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RNA, Small Interfering
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Tumor Suppressor Protein p53
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Clindamycin
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Mitomycin
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RNA
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Chloramphenicol
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Cytochromes c
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DNA
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Cyclooxygenase 1
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PTGS1 protein, human
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Prostaglandin-Endoperoxide Synthases
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Poly(ADP-ribose) Polymerases
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beta-Galactosidase
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CASP3 protein, human
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Caspase 3
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Caspases
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Minocycline
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Doxycycline