title: Activation of nuclear factor kappaB through the IKK complex by the topoisomerase poisons SN38 and doxorubicin: a brake to apoptosis in HeLa human carcinoma cells.
abstract: The transcription factor nuclear factor (NF) kappaB is involved in the regulation of cell survival. NFkappaB is activated in many malignant tumors and seems to play a role in the resistance to cytostatic treatments and escape from apoptosis. We have studied the effects on NFkappaB activation of two topoisomerase poisons and DNA damaging agents that are used in chemotherapy: SN38 (7-ethyl-10-hydroxycamptothecin), the active metabolite of CPT11, and doxorubicin. In HeLa cells, both drugs activate NFkappaB using a preexisting pathway that requires a functional IkappaB-specific kinase complex, IkappaB-specific kinase activation, IkappaB-alpha phosphorylation, and degradation. Blocking NFkappaB activation by stable expression of a mutant super-repressor IkappaB-alpha molecule sensitized HeLa cells to the apoptotic actions of drugs and tumor necrosis factor. RNase protection assay analysis demonstrate that NFkappaB is involved in the regulation of a complex pattern of gene activation and repression during the cellular response of HeLa cells to topoisomerase poisons. The blockade of NF-kappaB activation seems to shift the death/survival balance toward apoptosis.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale U526, Activation des Cellules Hématopoïétiques, Physiologie de la Survie et de la Mort Cellulaires et Infections Virales, 06107 Nice cedex 02, France.
authors.forename: V
authors.initials: V
authors.lastname: Bottero
authors.forename: V
authors.initials: V
authors.lastname: Busuttil
authors.forename: A
authors.initials: A
authors.lastname: Loubat
authors.forename: N
authors.initials: N
authors.lastname: Magné
authors.forename: J L
authors.initials: JL
authors.lastname: Fischel
authors.forename: G
authors.initials: G
authors.lastname: Milano
authors.forename: J F
authors.initials: JF
authors.lastname: Peyron
mesh_terms: D000903:Antibiotics, Antineoplastic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D002166:Camptothecin / Q000031:analogs & derivatives* / Q000494:pharmacology*; D002470:Cell Survival / Q000235:genetics; D003513:Cycloheximide / Q000494:pharmacology; D004249:DNA Damage / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000378:metabolism; D004317:Doxorubicin / Q000494:pharmacology*; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D006367:HeLa Cells; D006801:Humans; D051550:I-kappa B Kinase; D020672:I-kappa B Proteins; D000077146:Irinotecan; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000378:metabolism*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D059004:Topoisomerase I Inhibitors; D059005:Topoisomerase II Inhibitors
chemical_list: D000903:Antibiotics, Antineoplastic; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D020672:I-kappa B Proteins; D016328:NF-kappa B; C000606204:NFKBIA protein, human; D059004:Topoisomerase I Inhibitors; D059005:Topoisomerase II Inhibitors; D000072000:NF-KappaB Inhibitor alpha; D000077146:Irinotecan; D004317:Doxorubicin; D003513:Cycloheximide; D017346:Protein Serine-Threonine Kinases; C496559:CHUK protein, human; D051550:I-kappa B Kinase; C496560:IKBKB protein, human; C496565:IKBKE protein, human; D002166:Camptothecin