Blood, Vol. 94 No. 12 (December 15), 1999:
pp. 4060-4066
Amifostine Inhibits Hematopoietic Progenitor Cell Apoptosis by
Activating NF-
B/Rel Transcription Factors
Maria Fiammetta Romano,
Annalisa Lamberti,
Rita Bisogni,
Corrado Garbi,
Antonio M. Pagnano,
Pasquale Auletta,
Pierfrancesco Tassone,
Maria Caterina Turco, and
Salvatore Venuta
From the Dipartimento di Biochimica e Biotecnologie Mediche,
"Federico II" University, Naples, Italy; the Dipartimento di
Oncologia Sperimentale, Cancer Institute "Pascale," Naples,
Italy; the Dipartimento di Patologia e Biologia Molecolare e Cellulare
and the Clinica Ostetrica e Ginecologica, "Federico II"
University, Naples, Italy; and the Dipartimento di Medicina
Sperimentale e Clinica, University of Catanzaro, Catanzaro, Italy.
We investigated the involvement of NF-
B/Rel transcription factors
that reportedly can inhibit apoptosis in various cell types in the
antiapoptotic mechanism of the cytoprotectant amifostine. In the
nontumorigenic murine myeloid progenitor 32D cells incubated with
amifostine, we detected a reduction of the IB
cytoplasmic levels
by Western blotting and a raising of nuclear NF-B/Rel complexes by
electrophoretic mobility shift assay. Amifostine inhibited by more than
30% the growth factor deprivation-induced apoptosis, whereas its
effect failed when we blocked the NF-B/Rel activity with an
NF-B/Rel-binding phosphorothioate decoy oligodeoxynucleotide. In
human cord blood CD34+ cells, the NF-B/Rel p65 subunit
was detectable (using immunofluorescence analysis) mainly in the
cytoplasm in the absence of amifostine, whereas its presence was
appreciable in the nuclei of cells incubated with the cytoprotectant.
In 4 CD34+ samples incubated for 3 days in
cytokine-deficient conditions, cell apoptosis was reduced by more than
30% in the presence of amifostine (or amifostine plus a control
oligo); the effect of amifostine was abolished in cultures with the
decoy oligo. These findings indicate that the inhibition of
hematopoietic progenitor cell apoptosis by amifostine requires the
induction of NF-B/Rel factors and that the latter can therefore
exert an antiapoptotic activity in the hematopoietic progenitor cell
compartment. Furthermore, the identification of this specific mechanism
underlying the survival-promoting activity of amifostine lends support
to the possible use of this agent in apoptosis-related pathologies,
such as myelodysplasias.
