Abstract
Cyclooxygenase-2 and release of prostaglandin E2 are up-regulated in replicative senescence of dermal and prostate fibroblasts and in H(2)O(2)-induced premature senescence of IMR-90 lung fibroblasts expressing the catalytic subunit of telomerase. Inhibition of cyclooxygenase-2 activity by specific chemical inhibitor or siRNA attenuates the H(2)O(2)-induced increase of senescence associated beta-galactosidase positive cells and attenuates growth arrest. In this work, p38(MAPK) activation and increased DNA binding activities of ATF-2 and p53 are shown to mediate cyclooxygenase-2 overexpression in premature senescence.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Activating Transcription Factor 2 / genetics
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Activating Transcription Factor 2 / metabolism*
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Cell Line
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Cell Proliferation / drug effects*
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Cellular Senescence / drug effects*
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Cyclooxygenase 2 / genetics
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Cyclooxygenase 2 / metabolism*
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Cyclooxygenase 2 Inhibitors / pharmacology
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Enzyme Activation
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Fibroblasts / drug effects*
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Fibroblasts / enzymology
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Humans
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Hydrogen Peroxide / pharmacology*
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NF-kappa B / metabolism
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Protein Kinase Inhibitors / pharmacology
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RNA Interference
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RNA, Small Interfering / metabolism
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Signal Transduction / drug effects
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Telomerase / genetics
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Telomerase / metabolism
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Tumor Suppressor Protein p53 / genetics
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Tumor Suppressor Protein p53 / metabolism*
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Up-Regulation
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p38 Mitogen-Activated Protein Kinases / antagonists & inhibitors
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p38 Mitogen-Activated Protein Kinases / metabolism
Substances
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ATF2 protein, human
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Activating Transcription Factor 2
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Cyclooxygenase 2 Inhibitors
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NF-kappa B
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Protein Kinase Inhibitors
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RNA, Small Interfering
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TP53 protein, human
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Tumor Suppressor Protein p53
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Hydrogen Peroxide
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Cyclooxygenase 2
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PTGS2 protein, human
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p38 Mitogen-Activated Protein Kinases
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TERT protein, human
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Telomerase