TY - JOUR
T1 - Delta-lactoferrin induces cell death via the mitochondrial death signaling pathway by upregulating bax expression
AU - Hardivillé, Stéphan
AU - Escobar-Ramirez, Adelma
AU - Pina-Canceco, Soccoro
AU - Elass, Elisabeth
AU - Pierce, Annick
N1 - Funding Information:
Acknowledgments This investigation was supported in part by the CNRS UMR 8576 (Unité de Glycobiologie Structurale et Fonctionnelle), the Institut Fédératif de Recherche n° 147, the Université des Sciences et Technologies de Lille I, the Comité du Nord de la Ligue Nationale contre le Cancer. We would like to thank Dr. R. J. Pierce (CIIL, Institut Pasteur de Lille, France) for critical reading of this manuscript.
Publisher Copyright:
© 2014 Springer Science+Business Media New York.
PY - 2014/5/14
Y1 - 2014/5/14
N2 - Delta-lactoferrin (δLf) is a transcription factor belonging to the lactoferrin family, the expression of which inhibits cell proliferation and leads to Skp1 and DcpS gene transactivation. In this study, we showed that δLf expression also induces cell death via apoptosis in HEK 293 and MCF7 cells using a cell viability assay and DNA fragmentation. Western blot analyses showed that apoptosis was caspase-9, 7 and 8 dependent. Proteolytic cleavage of the endonuclease PARP was significantly increased. The levels of expression of Bcl family members were detected by immunochemistry and showed that the Bcl-xl/Bax and Bcl-2/Bax protein ratios were decreased. We determined that the pro-apoptotic effects of δLf are mainly mediated by the activation of the mitochondria-dependent death-signaling pathway. Apoptosis induction by δLf is concomitant with increased cellular levels of Bax protein. Analysis of the Bax promoter region detected a δLf response element located at -155 bp from the transcription start site. Both luciferase reporter gene and chromatin immunoprecipitation assays confirmed that δLf interacts in vitro and in vivo specifically with this sequence. Its deletion, realized using directed mutagenesis, totally abolished δLf transcriptional activity, identifying it as a δLf-responsive element. These results indicate that the Bax gene is a novel δLf target. Moreover we also showed that the O-GlcNAc/P interplay, which controls δLf transcriptional activity, modulates Bax transactivation.
AB - Delta-lactoferrin (δLf) is a transcription factor belonging to the lactoferrin family, the expression of which inhibits cell proliferation and leads to Skp1 and DcpS gene transactivation. In this study, we showed that δLf expression also induces cell death via apoptosis in HEK 293 and MCF7 cells using a cell viability assay and DNA fragmentation. Western blot analyses showed that apoptosis was caspase-9, 7 and 8 dependent. Proteolytic cleavage of the endonuclease PARP was significantly increased. The levels of expression of Bcl family members were detected by immunochemistry and showed that the Bcl-xl/Bax and Bcl-2/Bax protein ratios were decreased. We determined that the pro-apoptotic effects of δLf are mainly mediated by the activation of the mitochondria-dependent death-signaling pathway. Apoptosis induction by δLf is concomitant with increased cellular levels of Bax protein. Analysis of the Bax promoter region detected a δLf response element located at -155 bp from the transcription start site. Both luciferase reporter gene and chromatin immunoprecipitation assays confirmed that δLf interacts in vitro and in vivo specifically with this sequence. Its deletion, realized using directed mutagenesis, totally abolished δLf transcriptional activity, identifying it as a δLf-responsive element. These results indicate that the Bax gene is a novel δLf target. Moreover we also showed that the O-GlcNAc/P interplay, which controls δLf transcriptional activity, modulates Bax transactivation.
KW - Apoptosis
KW - Delta-lactoferrin
KW - Lactoferrin
KW - O-GlcNAcylation
KW - Transcription factor
KW - Tumor-suppressor
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U2 - 10.1007/s10534-014-9744-5
DO - 10.1007/s10534-014-9744-5
M3 - Article
C2 - 24824995
AN - SCOPUS:84908086844
SN - 0966-0844
VL - 27
SP - 875
EP - 889
JO - BioMetals
JF - BioMetals
IS - 5
ER -