Fludarabine induces pro-inflammatory activation of human monocytic cells through a MAPK/ERK pathway.
Fludarabine is a nucleoside analogue that has been successfully employed for the treatment of low-grade lymphoid malignancies and, more recently, in nonmyeloablative preparative regimens for stem cell transplantation, due to its strong cytotoxic activity on lymphocytes. In this paper, we show that fludarabine can also induce pro-inflammatory stimulation of monocytic cells, as evaluated by increased expression of ICAM-1 and IL-8 release. To study the mechanisms involved, we employed selective inhibitors of MAPK and NF-kappaB pathways, both of which have been implicated in the modulation of ICAM-1 and IL-8. Our results showed that fludarabine effects were mediated through the activation of ERK and were independent on p38, JNK or NF-kappaB pathways. By Western blotting analysis we corroborated that fludarabine induced a rapid activation of ERK that was sustained for at least 30 min. Moreover, pro-inflammatory activation of monocytic cells by fludarabine was largely attenuated by coadministration of the free radical scavenger N-acetylcysteine suggesting the involvement of reactive oxygen species in fludarabine effects. Finally, we showed that fludarabine induced the activation of the transcription factor AP-1 not only in monocytic cells but also in non-proliferating lymphocytes from chronic lymphocytic leukemia. It is possible that some of fludarabine side effects in vivo may be attributed to cell activation/differentiation rather than induction of apoptosis.
Laboratorio de Inmunología Oncológica, IIHEMA, Academia Nacional de Medicina, Buenos Aires, Argentina.
Paula
P
Fernández-Calotti
Romina
R
Gamberale
Mónica
M
Costas
Julio
J
Sánchez Avalos
Jorge
J
Geffner
Mirta
M
Giordano
D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis; D001402:B-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology; D018799:Intercellular Adhesion Molecule-1 / Q000276:immunology; D016209:Interleukin-8 / Q000276:immunology; D009000:Monocytes / Q000187:drug effects* / Q000276:immunology; D018808:Transcription Factor AP-1 / Q000276:immunology; D020298:U937 Cells; D014740:Vidarabine / Q000031:analogs & derivatives* / Q000494:pharmacology
D000970:Antineoplastic Agents; D007166:Immunosuppressive Agents; D016209:Interleukin-8; D018808:Transcription Factor AP-1; D018799:Intercellular Adhesion Molecule-1; D048049:Extracellular Signal-Regulated MAP Kinases; D014740:Vidarabine; C024352:fludarabine