TY - JOUR
T1 - Vorinostat Induces Apoptosis and Differentiation in Myeloid Malignancies
T2 - Genetic and Molecular Mechanisms
AU - Silva, Gabriela de Medeiros
AU - Cardoso, Bruno
AU - Belo, Hélio
AU - Almeida, António
N1 - info:eu-repo/grantAgreement/FCT/SFRH/SFRH%2FBPD%2F46494%2F2008/PT#
This study was funded by a research grant from the Portuguese Association Against Leukemia, from the IPOLFG Oncology Research Fund, and a post-doctoral fellowship from "Fundacao para a Ciencia e Tecnologia" (SFRH/BPD/46494/2008) for GS. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Dr AMA receives consulting fees from Celgene and Novartis and is on the board of speakers for Bristol-Meyer Squibb, Shire and Amgen. This does not alter the authors' adherence to all the PLOS ONE policies on sharing data and materials.
PY - 2013/1/8
Y1 - 2013/1/8
N2 - Background: Aberrant epigenetic patterns are central in the pathogenesis of haematopoietic diseases such as myelodysplastic syndromes (MDS) and acute myeloid leukaemia (AML). Vorinostat is a HDACi which has produced responses in these disorders. The purpose of this study was to address the functional effects of vorinostat in leukemic cell lines and primary AML and MDS myeloid cells and to dissect the genetic and molecular mechanisms by which it exerts its action. Methodology/Principal Findings: Functional assays showed vorinostat promoted cell cycle arrest, inhibited growth, and induced apoptosis and differentiation of K562, HL60 and THP-1 and of CD33(+) cells from AML and MDS patients. To explore the genetic mechanism for these effects, we quantified gene expression modulation by vorinostat in these cells. Vorinostat increased expression of genes down-regulated in MDS and/or AML (cFOS, COX2, IER3, p15, RAI3) and suppressed expression of genes over-expressed in these malignancies (AXL, c-MYC, Cyclin D1) and modulated cell cycle and apoptosis genes in a manner which would favor cell cycle arrest, differentiation, and apoptosis of neoplastic cells, consistent with the functional assays. Reporter assays showed transcriptional effect of vorinostat on some of these genes was mediated by proximal promoter elements in GC-rich regions. Vorinostat-modulated expression of some genes was potentiated by mithramycin A, a compound that interferes with SP1 binding to GC-rich DNA sequences, and siRNA-mediated SP1 reduction. ChIP assays revealed vorinostat inhibited DNA binding of SP1 to the proximal promoter regions of these genes. These results suggest vorinostat transcriptional action in some genes is regulated by proximal promoter GC-rich DNA sequences and by SP1. Conclusion: This study sheds light on the effects of vorinostat in AML and MDS and supports the implementation of clinical trials to explore the use of vorinostat in the treatment of these diseases.
AB - Background: Aberrant epigenetic patterns are central in the pathogenesis of haematopoietic diseases such as myelodysplastic syndromes (MDS) and acute myeloid leukaemia (AML). Vorinostat is a HDACi which has produced responses in these disorders. The purpose of this study was to address the functional effects of vorinostat in leukemic cell lines and primary AML and MDS myeloid cells and to dissect the genetic and molecular mechanisms by which it exerts its action. Methodology/Principal Findings: Functional assays showed vorinostat promoted cell cycle arrest, inhibited growth, and induced apoptosis and differentiation of K562, HL60 and THP-1 and of CD33(+) cells from AML and MDS patients. To explore the genetic mechanism for these effects, we quantified gene expression modulation by vorinostat in these cells. Vorinostat increased expression of genes down-regulated in MDS and/or AML (cFOS, COX2, IER3, p15, RAI3) and suppressed expression of genes over-expressed in these malignancies (AXL, c-MYC, Cyclin D1) and modulated cell cycle and apoptosis genes in a manner which would favor cell cycle arrest, differentiation, and apoptosis of neoplastic cells, consistent with the functional assays. Reporter assays showed transcriptional effect of vorinostat on some of these genes was mediated by proximal promoter elements in GC-rich regions. Vorinostat-modulated expression of some genes was potentiated by mithramycin A, a compound that interferes with SP1 binding to GC-rich DNA sequences, and siRNA-mediated SP1 reduction. ChIP assays revealed vorinostat inhibited DNA binding of SP1 to the proximal promoter regions of these genes. These results suggest vorinostat transcriptional action in some genes is regulated by proximal promoter GC-rich DNA sequences and by SP1. Conclusion: This study sheds light on the effects of vorinostat in AML and MDS and supports the implementation of clinical trials to explore the use of vorinostat in the treatment of these diseases.
KW - CANCER-CELLS
KW - CELL LYMPHOMA
KW - HISTONE DEACETYLASE INHIBITOR
KW - BONE-MARROW
KW - MYELODYSPLASTIC SYNDROMES
KW - TRANSCRIPTION FACTORS
KW - CD34(+) CELLS
KW - SP FAMILY
KW - DOWN-REGULATION
KW - SUBEROYLANILIDE HYDROXAMIC ACID
KW - HISTONE DEACETYLASE INHIBITOR
KW - SUBEROYLANILIDE HYDROXAMIC ACID
KW - MYELODYSPLASTIC SYNDROMES
KW - DOWN-REGULATION
KW - BONE-MARROW
KW - TRANSCRIPTION FACTORS
KW - CELL LYMPHOMA
KW - CD34(+) CELLS
KW - CANCER-CELLS
KW - SP FAMILY
U2 - 10.1371/journal.pone.0053766
DO - 10.1371/journal.pone.0053766
M3 - Article
C2 - 23320102
SN - 1932-6203
VL - 8
SP - Online
JO - PLoS ONE
JF - PLoS ONE
IS - 1
ER -
