title: Arsenic trioxide induces apoptosis of cutaneous T cell lymphoma cells: evidence for a partially caspase-independent pathway and potentiation by ascorbic acid (vitamin C).
abstract: Arsenic trioxide (As2O3) displays apoptogenic properties against various types of hematopoietic malignancies. We investigated the effects of As2O3 on the viability of the cutaneous T cell lymphoma cell lines HuT-78, SeAx, and Myla, and of peripheral blood mononuclear cells from patients with Sézary syndrome, by using propidium iodide and annexin-V staining, terminal deoxyuridine triphosphate nick end labeling (TUNEL), cell cycle analysis, mitochondrial transmembrane potential (delta psi(m)) alterations, cytochrome c release, and detection of processed caspase-3. We also report in vivo effects of As2O3 in two patients with cutaneous T cell lymphoma. The results show that As2O3 induces apoptosis of cutaneous T cell lymphoma lines and of Sézary cells from patients in a time- and concentration-dependent manner in vitro, as demonstrated by annexin-V staining, mitochondrial depolarization, and DNA fragmentation. Ascorbic acid 100 microM potentiated As2O3-induced Sézary cell death, whereas interferon-alpha had no synergistic effect. As2O3-induced Sézary cell death involves activation of caspase-3, cleavage of poly(ADP-ribose)polymerase, and cytochrome c release, but was only partially inhibited by the pancaspase inhibitor Z-VAD.fluoromethylketone. Finally, As2O3 was administered to two patients with cutaneous T cell lymphoma, allowing us to obtain a partial response in one case, whereas stability was observed in the second patient. These results demonstrate that As2O3 synergizes with ascorbic acid to induce Sézary cell death at clinically achievable concentrations, through a caspase-partially independent pathway, and provide a rationale for further in vivo studies addressing the therapeutic efficacy of As2O3 in cutaneous T cell lymphoma patients.
authors: Skin Research Institute, Institut National de la Santé et de la Recherche Médicale U532, Department of Dermatology, Hôpital Saint-Louis, Paris, France. l.michel@chu-stlouis.fr
authors: Laurence
authors: L
authors: Michel
authors: Alain
authors: A
authors: Dupuy
authors: Francette
authors: F
authors: Jean-Louis
authors: Aurore
authors: A
authors: Sors
authors: Joël
authors: J
authors: Poupon
authors: Manuelle
authors: M
authors: Viguier
authors: Philippe
authors: P
authors: Musette
authors: Louis
authors: L
authors: Dubertret
authors: Laurent
authors: L
authors: Degos
authors: Hervé
authors: H
authors: Dombret
authors: Hervé
authors: H
authors: Bachelez
mesh_terms: D000368:Aged; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D000077237:Arsenic Trioxide; D001152:Arsenicals / Q000008:administration & dosage* / Q000494:pharmacology; D001205:Ascorbic Acid / Q000494:pharmacology*; D020169:Caspases / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D002999:Clone Cells; D004357:Drug Synergism; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000187:drug effects; D016410:Lymphoma, T-Cell, Cutaneous / Q000188:drug therapy*; D008875:Middle Aged; D008928:Mitochondria / Q000187:drug effects; D010087:Oxides / Q000008:administration & dosage* / Q000494:pharmacology; D012878:Skin Neoplasms / Q000188:drug therapy*
chemical_list: D000970:Antineoplastic Agents; D000975:Antioxidants; D001152:Arsenicals; D010087:Oxides; D020169:Caspases; D001205:Ascorbic Acid; D000077237:Arsenic Trioxide