Differential effects of chemotherapeutic drugs versus the MDM-2 antagonist nutlin-3 on cell cycle progression and induction of apoptosis in SKW6.4 lymphoblastoid B-cells.
We have compared the cytotoxic/cytostatic responses of the SKW6.4 lymphoblastoid B-cells to the alkylating agent chlorambucil, the purine analog fludarabine, the non-genotoxic activator of the p53 pathway, Nutlin-3, used alone or in association with the death-inducing ligand recombinant TRAIL. Exposure to chlorambucil, fludarabine, and Nutlin-3 induced p53 accumulation and variably affected cell cycle progression in SKW6.4 lymphoblastoid cells. In particular, chlorambucil induced cell cycle accumulation at the G2/M checkpoint; Nutlin-3 induced early cell cycle arrest at the G1/S checkpoint, while fludarabine showed an intermediate behavior. On the other hand, recombinant TRAIL alone did not affect cell cycle progression but induced a rapid increase of apoptosis. Analysis of the gene expression profile of the p53-transcriptional targets showed distinct features between chlorambucil, Nutlin-3 and fludarabine, which likely account for their differential effect on cell cycle in SKW6.4 cells. In particular, chlorambucil upregulated the steady-state mRNA expression of SFN/14-3-3sigma, a gene involved in G2/M cell cycle arrest. Of note, all agonists upregulated TRAIL-R2 expression in SKW6.4 cells both at the mRNA and protein levels. Consistently, pretreatment with chlorambucil, fludarabine and Nutlin-3 enhanced SKW6.4 sensitivity to TRAIL-mediated apoptosis.
Barbarotto
Elisa
E
Department of Morphology and Embryology, University of Ferrara, Via Fossato di Mortara 66, 44100 Ferrara, Italy.
Corallini
Federica
F
Rimondi
Erika
E
Fadda
Roberto
R
Mischiati
Carlo
C
Grill
Vittorio
V
Vaccarezza
Mauro
M
Celeghini
Claudio
C
D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects*; D001402:B-Lymphocytes / Q000473:pathology; D001752:Blast Crisis / Q000473:pathology; D002453:Cell Cycle / Q000187:drug effects*; D045744:Cell Line, Tumor; D002699:Chlorambucil / Q000494:pharmacology; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology*; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000473:pathology*; D010879:Piperazines / Q000494:pharmacology*; D051736:Proto-Oncogene Proteins c-mdm2 / Q000037:antagonists & inhibitors*; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand / Q000235:genetics*; D015854:Up-Regulation / Q000235:genetics; D014740:Vidarabine / Q000031:analogs & derivatives / Q000494:pharmacology
D007093:Imidazoles; D010879:Piperazines; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D002699:Chlorambucil; C482205:nutlin 3; D051736:Proto-Oncogene Proteins c-mdm2; D014740:Vidarabine; C024352:fludarabine