title: Combined arsenic and retinoic acid treatment enhances differentiation and apoptosis in arsenic-resistant NB4 cells.
abstract: In the acute promyelocytic leukemia (APL) cell line NB4, as well as in APL patients' cells, arsenic trioxide (As2O3) leads to incomplete cell maturation, induction of apoptosis, as well as to the degradation of the oncogenic PML/RARalpha fusion protein. We have isolated an arsenic-resistant NB4 subline (NB4-AsR), which fails to undergo apoptosis, but maintains the partial differentiation response to this drug. When grown in the presence of As2O3, NB4-AsR cells degrade PML/RARalpha, slightly differentiate, and become more sensitive to serum deprivation-induced apoptosis. Similarly, in RA-resistant NB4-R1 cells, RA induced a significant PML/RARalpha degradation and yet failed to induce cell maturation. Thus, As2O3- or retinoic acid (RA)-induced PML/RARalpha degradation may be a prerequisite, but is not sufficient for the full differentiative/apoptotic response to these drugs. Strikingly, RA-triggered differentiation and apoptosis were greatly accelerated in As2O3-treated NB4-AsR cells. The synergism between these two agents in this setting could provide an experimental basis for combined or sequential RA/As2O3 therapies.
authors.affiliation: Centre National de la Recherche Scientifique Unité Propre de Recherche 9051, Laboratoire associé au Comité de Paris de la Ligue Contre le Cancer, UIH, Université Paris VII, Service de Biochimie B, Hôpital St Louis, Paris, France.
authors.forename: M
authors.initials: M
authors.lastname: Giannì
authors.forename: M H
authors.initials: MH
authors.lastname: Koken
authors.forename: M K
authors.initials: MK
authors.lastname: Chelbi-Alix
authors.forename: G
authors.initials: G
authors.lastname: Benoit
authors.forename: M
authors.initials: M
authors.lastname: Lanotte
authors.forename: Z
authors.initials: Z
authors.lastname: Chen
authors.forename: H
authors.initials: H
authors.lastname: de Thé
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D000077237:Arsenic Trioxide; D001152:Arsenicals / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects; D019008:Drug Resistance, Neoplasm; D004357:Drug Synergism; D006801:Humans; D015473:Leukemia, Promyelocytic, Acute / Q000473:pathology; D018613:Microscopy, Confocal; D010087:Oxides / Q000494:pharmacology*; D014212:Tretinoin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D001152:Arsenicals; D010087:Oxides; D014212:Tretinoin; D000077237:Arsenic Trioxide