Role of GSTP1-1 in mediating the effect of As2O3 in the Acute Promyelocytic Leukemia cell line NB4.
Arsenic trioxide (As2O3) is a highly effective agent in the treatment of acute promyelocytic leukemia (APL), whereas other hematopoietic tumors are less responsive to this agent and mechanisms underlying As2O3,-resistance are poorly understood. To better understand the complex network of GSH-related pathways in As2O3 sensitivity, we investigated the role of GSH and GSH-relevant enzymes in an APL cell line sensitive to As2O3 (NB4) and in a resistant subclone (AsR). Cell proliferation, viability, and apoptosis were investigated in NB4 cells before and after treatment with 1 muM As2O3 and in AsR cells. In these experimental cell models, GSTP1-1, JNK1 and JNK2 proteins were analyzed by immunoblotting, and a kinase assay for JNK1 was performed. GSH levels as well as the activities of the enzymes glutathione peroxidase, glutathione transferase, gamma-Glutamylcysteynilsinthetase and superoxide dismutase were measured. NB4 cells treated with As2O3 showed a high level of oxidative stress and an increase of GSH levels. GSTP1-1 polymerization and JNK1 activation were detectable after 24 h and were followed by an increase of the apoptotic rate starting at 72 h. Neither GSTP1-1 polymerization nor JNK activation was found in AsR cells that showed a very low apoptotic rate. Our results suggest that APL sensitivity to As2O3 might be, at least in part, mediated by the balance between association and dissociation of JNK from GSTP1-1, depending on the redox status of the cell. Further investigation is warranted to find a way to interfere with this balance, whenever it might represent a mechanism of drug resistance.
Bernardini
Sergio
S
Department of Internal Medicine, University of Rome Tor Vergata, Viale Oxford 81, 00133, Rome, Italy. Bernardini@Med.UniRoma2.it
Nuccetelli
Marzia
M
Noguera
Nélida I
NI
Bellincampi
Lorenza
L
Lunghi
Paolo
P
Bonati
Antonio
A
Mann
Koren
K
Miller
Wilson H
WH
Federici
Giorgio
G
Lo Coco
Francesco
F
D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D000077237:Arsenic Trioxide; D001152:Arsenicals / Q000494:pharmacology* / Q000627:therapeutic use; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D019008:Drug Resistance, Neoplasm / Q000187:drug effects*; D004789:Enzyme Activation / Q000187:drug effects; D051549:Glutathione S-Transferase pi / Q000378:metabolism*; D006801:Humans; D015473:Leukemia, Promyelocytic, Acute / Q000188:drug therapy / Q000201:enzymology*; D009363:Neoplasm Proteins / Q000378:metabolism*; D010084:Oxidation-Reduction / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D010087:Oxides / Q000494:pharmacology* / Q000627:therapeutic use; D013997:Time Factors
D000970:Antineoplastic Agents; D001152:Arsenicals; D009363:Neoplasm Proteins; D010087:Oxides; C496556:GSTP1 protein, human; D051549:Glutathione S-Transferase pi; D000077237:Arsenic Trioxide