TY - JOUR
T1 - A novel Bim-BH3-derived Bcl-XL inhibitor
T2 - Biochemical characterization, in vitro, in vivo and ex-vivo anti-leukemic activity
AU - Ponassi, Raffaella
AU - Biasotti, Barbara
AU - Tomati, Valeria
AU - Bruno, Silvia
AU - Poggi, Alessandro
AU - Malacarne, Davide
AU - Cimoli, Guido
AU - Salis, Annalisa
AU - Pozzi, Sarah
AU - Miglino, Maurizio
AU - Damonte, Gianluca
AU - Cozzini, Pietro
AU - Spyraki, Francesca
AU - Campanini, Barbara
AU - Bagnasco, Luca
AU - Castagnino, Nicoletta
AU - Tortolina, Lorenzo
AU - Mumot, Anna
AU - Frassoni, Francesco
AU - Daga, Antonio
AU - Cilli, Michele
AU - Piccardi, Federica
AU - Monfardini, Ilaria
AU - Perugini, Miriam
AU - Zoppoli, Gabriele
AU - D'Arrigo, Cristina
AU - Pesenti, Raffaele
AU - Parodi, Silvio
PY - 2008/10/15
Y1 - 2008/10/15
N2 - BH3-only members of the Bcl-2 family exert a fundamental role in apoptosis induction. This work focuses on the development of a novel peptidic molecule based on the BH3 domain of Bim. The antiapoptotic molecule Bcl-XL, involved in cancer development/ progression and tumour resistance to cytotoxic drugs, is a target for Bim. According to a rational study of the structural interactions between wt Bim-BH3 and Bcl-XL, we replaced specific residues of Bim-BH3 with natural and non-natural aminoacids and added an internalizing sequence, thus increasing dramatically the inhibitory activity of our modified Bim-BH3 peptide, called 072RB. Confocal microscopy and flow cytometry demonstrated cellular uptake and internalization of 072RB, followed by co-localization with mitochondria. Multiparameter flow cytometry demonstrated that the 072RB dose-dependent growth inhibition of leukaemia cell lines was due to apoptotic cell death. No effect was observed when cells were treated with the internalizing vector alone or a mutated control peptide (single aminoacid substitution L94A). Ex-vivo derived leukemic cells from acute myeloid leukaemia (AML) patients underwent cell death when cultured in vitro in the presence of 072RB. Conversely, no significant cytotoxic effect was observed when 072RB was administered to cultures of peripheral blood mononuclear cells, either resting or PHA-stimulated, and bone marrow cells of normal donors. Xenografts of human AML cells in NOD/SCID mice displayed a significant delay of leukemic cell growth upon treatment with 072RB administered intravenously (15 mg/Kg three times, 48 hours after tumour cell injection). Altogether, these observations support the therapeutic potentials of this novel BH3 mimetic.
AB - BH3-only members of the Bcl-2 family exert a fundamental role in apoptosis induction. This work focuses on the development of a novel peptidic molecule based on the BH3 domain of Bim. The antiapoptotic molecule Bcl-XL, involved in cancer development/ progression and tumour resistance to cytotoxic drugs, is a target for Bim. According to a rational study of the structural interactions between wt Bim-BH3 and Bcl-XL, we replaced specific residues of Bim-BH3 with natural and non-natural aminoacids and added an internalizing sequence, thus increasing dramatically the inhibitory activity of our modified Bim-BH3 peptide, called 072RB. Confocal microscopy and flow cytometry demonstrated cellular uptake and internalization of 072RB, followed by co-localization with mitochondria. Multiparameter flow cytometry demonstrated that the 072RB dose-dependent growth inhibition of leukaemia cell lines was due to apoptotic cell death. No effect was observed when cells were treated with the internalizing vector alone or a mutated control peptide (single aminoacid substitution L94A). Ex-vivo derived leukemic cells from acute myeloid leukaemia (AML) patients underwent cell death when cultured in vitro in the presence of 072RB. Conversely, no significant cytotoxic effect was observed when 072RB was administered to cultures of peripheral blood mononuclear cells, either resting or PHA-stimulated, and bone marrow cells of normal donors. Xenografts of human AML cells in NOD/SCID mice displayed a significant delay of leukemic cell growth upon treatment with 072RB administered intravenously (15 mg/Kg three times, 48 hours after tumour cell injection). Altogether, these observations support the therapeutic potentials of this novel BH3 mimetic.
KW - Apoptosis
KW - Bim-BH3
KW - Leukaemia
KW - Multi-parameter flow cytometry
KW - Targeted therapy
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UR - http://www.scopus.com/inward/citedby.url?scp=54049131208&partnerID=8YFLogxK
M3 - Article
C2 - 18843207
AN - SCOPUS:54049131208
VL - 7
SP - 3211
EP - 3224
JO - Cell Cycle
JF - Cell Cycle
SN - 1538-4101
IS - 20
ER -