Stress-induced activation of the p53 tumor suppressor in leukemia cells and normal lymphocytes requires mitochondrial activity and reactive oxygen species.
The p53 system is highly stress sensitive and integrates diverse intracellular signals in a complex and poorly defined manner. We report on the high dependence of stress-induced p53 activation on mitochondrial activity. Down-regulation of mitochondrial transmembrane potential (MTMP) by inhibitors of electron transport (rotenone, thenoyltrifluoroacetone (TTFA)) and adenosine triphosphate (ATP) synthesis (oligomycin) prevented stress-induced p53 protein accumulation and abrogated p53-dependent apoptosis in a wild-type p53 leukemia cell line MOLT-3, in primary leukemia cells and in normal T lymphocytes. Using genome-wide gene expression analysis, stress-induced up-regulation of the p53 transcriptional targets and their specific inhibition by oligomycin has been demonstrated. Oligomycin did not impair p53-independent apoptosis and caused only a slight reduction of intracellular ATP levels. Reactive oxygen species (ROS) localized to mitochondria decreased in the presence of oligomycin, and stress-induced p53 activation showed strong ROS sensitivity both in leukemic and normal cells. These observations identify mitochondrial activity, described by MTMP and ROS levels, as a critical intracellular determinant of the p53 stress sensitivity and suggest potential implications of this linkage in the mechanisms of chemoresistance of acute leukemia cells.
Karawajew
Leonid
L
Department of Hematology, Oncology, and Tumor Immunology, Robert-Rossle-Clinic, HELIOS Klinikum Berlin-Buch, Charité Medical School, Berlin, Germany. karawajew@rrk.charite-buch.de <karawajew@rrk.charite-buch.de>
Rhein
Peter
P
Czerwony
Grit
G
Ludwig
Wolf-Dieter
WD
D000255:Adenosine Triphosphate / Q000737:chemistry / Q000378:metabolism; D017209:Apoptosis; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D002614:Chelating Agents / Q000494:pharmacology; D015536:Down-Regulation; D019008:Drug Resistance, Neoplasm; D004583:Electrons; D005047:Etoposide / Q000494:pharmacology; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D016678:Genome; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism; D008214:Lymphocytes / Q000378:metabolism*; D008564:Membrane Potentials; D008928:Mitochondria / Q000378:metabolism*; D009154:Mutation; D009840:Oligomycins / Q000494:pharmacology; D020411:Oligonucleotide Array Sequence Analysis; D018384:Oxidative Stress; D010100:Oxygen / Q000378:metabolism; D010766:Phosphorylation; D017382:Reactive Oxygen Species; D012402:Rotenone / Q000494:pharmacology; D013601:T-Lymphocytes / Q000378:metabolism; D013804:Thenoyltrifluoroacetone / Q000494:pharmacology; D013997:Time Factors; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D014475:Uncoupling Agents / Q000494:pharmacology; D015854:Up-Regulation
D002614:Chelating Agents; D009840:Oligomycins; D017382:Reactive Oxygen Species; D016159:Tumor Suppressor Protein p53; D014475:Uncoupling Agents; D012402:Rotenone; D013804:Thenoyltrifluoroacetone; D005047:Etoposide; D000255:Adenosine Triphosphate; D010100:Oxygen