Histone Deacetylase HDAC6 Inhibitor CAY10603 Blocks G1/S of the Cell Cycle and Promotes Senescence of Murine Fibroblasts Transformed with E1A and cHa-ras Oncogenes

2019 ◽  
Vol 13 (4) ◽  
pp. 268-275
Author(s):  
A.N. Kukushkin ◽  
S. B. Svetlikova
Keyword(s):  
Cell Cycle ◽  
Histone Deacetylase ◽  
Murine Fibroblasts ◽  
Hdac6 Inhibitor ◽  
Ras Oncogenes

Preclinical Screening of the HDAC6 Inhibitor Rocilinostat (ACY-1215) Combined with Bendamustine in Lymphoma Cell Lines

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3124-3124 ◽  
Author(s):  
Maria Cosenza ◽  
Monica Civallero ◽  
Samantha Pozzi ◽  
Luigi Marcheselli ◽  
Stefano Sacchi
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
T Cell ◽  
Histone Deacetylase ◽  
Cell Lines ◽  
Cell Lymphoma ◽  
Lymphoma Cell ◽  
Ic50 Values ◽  
Hdac6 Inhibitor ◽  
Dose Dependent

Abstract Background and Purpose. Histone deacetylase (HDAC) inhibitors are emerging as an exciting new therapeutic option for lymphoid malignancies. Rocilinostat (ACY-1215) is a novel selective histone deacetylase 6 (HDAC6) inhibitor. HDAC6 is a class IIB histone deacetylase that plays an important role in cellular response to environmental stress. The purpose of the present study was to evaluate the preclinical activity of HDAC6 inhibitor rocilinostat (Acetylon) alone and the potential of combining of rocilinostat with bendamustine (alkylating agent) in lymphoma cell lines. Methods. Anti-tumor activity of rocilinostat was investigated using a panel of six lymphoma cell lines: two follicular lymphoma (FL) (WSU-NHL, RL), two mantle cell lymphoma (MCL) (Granta-519, Jeko-1) and two T-cell lymphoma (TCL) (HUT-78 - cutaneous T cell lymphoma and Karpas-299 - anaplastic lymphoma cells). IC50 values of each drug were calculated from curves based on rocilinostat concentrations (0,01 - 100 µM), and bendamustine (25 - 300 µM) after 24, 48 and 72 h. The cell proliferation was determined by using the CellTiter 96® Aqueous One Solution Cell Proliferation Assay kit and cell cytotoxicity with MTT-assay. The interaction between drugs was evaluated by isobologram analysis based upon the Chou-Talalay method to determine if the combination were additive or synergistic. Apoptosis and cell cycle analysis were measured by flow cytometry. Results . Exposure of lymphoma cell lines for 24 - 72 h resulted in time- and dose-dependent inhibition of cell growth with IC50 values ranging from 0.17 to 8.65 μmol/L. Significant cytotoxic effect was evident after 48 hours of rocilinostat incubation by MTT assays with the most sensitive cell lines being WSU-NHL and Hut-78 (IC50: 1.97 – 1.5 μmol/L) and the least sensitive being Granta-519 (IC50: 20 μmol/L). Rocilinostat alone induced time- and dose-dependent increases in apoptosis. After 48 h of treatment with doses ranging from 1 to 20 μmol/L, the percentage of apoptotic cells in early and late apoptosis increased from 11% to 56% and induced an increase in the percentage of cells in the G0/G1 phase of the cell cycle compared with untreated controls.Synergy analyses were done using WSU-NHL, Hut-78 and Granta-519 cells treated with different concentrations of rocilinostat (0, 2, 4 and 8 μmol/L) in combination with bendamustine (0, 10, 20, 40, 50 and 100 μmol/L) and lymphoma cells were assayed by MTT at 24 and 48 h. A clear synergistic interaction, confirmed by the Chou-Talalay method, was observed after 24 h using low concentrations of two drugs which are lower than their IC50 values. Acy-1215 (4 and 8 μmol/L) and bendamustine (20 and 40 μmol/L) showed a synergistic interaction with CI (combination index) values ranging between 0.13 and 0,34 in Hut-78 and WSU-NHL cells. The treatment of Granta-519 cells with rocilinostat (20 and 40 μmol/L) with bendamustine (50 and 100 μmol/L) showed CI values of 0,26 and 0,21 respectively. The drug combinations enhanced apoptosis as assessed by AnnexinV/PI staining. The percentage of apoptosis after 24 h ranged from 55 to 80 %. Furthermore, rocilinostat with bendamustine reduced the proportion of cells in the G0/G1 and S phases and caused an increase of “sub-G0/G1” peak. Finally, the combination of rocilinostat with bendamustine did not trigger relevant decreases in the viability of normal peripheral blood mononuclear cells (PBMNCs). Conclusion . These preclinical results indicate that rocilinostat can have marked activity in lymphoma cell lines in combination with bendamustine. Further investigation is required to continue to study the activity of rocilinostat in lymphoma both as a single agent and in combinations. Disclosures No relevant conflicts of interest to declare.

scholarly journals HIV-1 Vpr activates host CRL4-DCAF1 E3 ligase to degrade histone deacetylase SIRT7

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Xiaohong Zhou ◽  
Christina Monnie ◽  
Maria DeLucia ◽  
Jinwoo Ahn
Keyword(s):  
Cell Cycle ◽  
Dna Repair ◽  
Cell Cycle Arrest ◽  
Histone Deacetylase ◽  
E3 Ligase ◽  
Cycle Arrest ◽  
Wide Range ◽  
In Vitro Reconstitution ◽  
Hiv 1

Abstract Background Vpr is a virion-associated protein that is encoded by lentiviruses and serves to counteract intrinsic immunity factors that restrict infection. HIV-1 Vpr mediates proteasome-dependent degradation of several DNA repair/modification proteins. Mechanistically, Vpr directly recruits cellular targets onto DCAF1, a substrate receptor of Cullin 4 RING E3 ubiquitin ligase (CRL4) for poly-ubiquitination. Further, Vpr can mediate poly-ubiquitination of DCAF1-interacting proteins by the CRL4. Because Vpr-mediated degradation of its known targets can not explain the primary cell-cycle arrest phenotype that Vpr expression induces, we surveyed the literature for DNA-repair-associated proteins that interact with the CRL4-DCAF1. One such protein is SIRT7, a deacetylase of histone 3 that belongs to the Sirtuin family and regulates a wide range of cellular processes. We wondered whether Vpr can mediate degradation of SIRT7 via the CRL4-DCAF1. Methods HEK293T cells were transfected with cocktails of plasmids expressing DCAF1, DDB1, SIRT7 and Vpr. Ectopic and endogeneous levels of SIRT7 were monitered by immunoblotting and protein–protein interactions were assessed by immunoprecipitation. For in vitro reconstitution assays, recombinant CRL4-DCAF1-Vpr complexes and SIRT7 were prepared and poly-ubiqutination of SIRT7 was monitored with immunoblotting. Results We demonstrate SIRT7 polyubiquitination and degradation upon Vpr expression. Specifically, SIRT7 is shown to interact with the CRL4-DCAF1 complex, and expression of Vpr in HEK293T cells results in SIRT7 degradation, which is partially rescued by CRL inhibitor MNL4924 and proteasome inhibitor MG132. Further, in vitro reconstitution assays show that Vpr induces poly-ubiquitination of SIRT7 by the CRL4-DCAF1. Importantly, we find that Vpr from several different HIV-1 strains, but not HIV-2 strains, mediates SIRT7 poly-ubiquitination in the reconstitution assay and degradation in cells. Finally, we show that SIRT7 degradation by Vpr is independent of the known, distinctive phenotype of Vpr-induced cell cycle arrest at the G2 phase, Conclusions Targeting histone deacetylase SIRT7 for degradation is a conserved feature of HIV-1 Vpr. Altogether, our findings reveal that HIV-1 Vpr mediates down-regulation of SIRT7 by a mechanism that does not involve novel target recruitment to the CRL4-DCAF1 but instead involves regulation of the E3 ligase activity.

scholarly journals Family with Sequence Similarity 60A (FAM60A) Protein Is a Cell Cycle-fluctuating Regulator of the SIN3-HDAC1 Histone Deacetylase Complex

2012 ◽  
Vol 287 (39) ◽  
pp. 32346-32353 ◽  
Author(s):  
Ivan M. Muñoz ◽  
Thomas MacArtney ◽  
Luis Sanchez-Pulido ◽  
Chris P. Ponting ◽  
Sonia Rocha ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Histone Deacetylase ◽  
Sequence Similarity ◽  
A Cell

scholarly journals Histone Deacetylase Inhibitors Trigger a G2 Checkpoint in Normal Cells That Is Defective in Tumor Cells

2000 ◽  
Vol 11 (6) ◽  
pp. 2069-2083 ◽  
Author(s):  
Ling Qiu ◽  
Andrew Burgess ◽  
David P. Fairlie ◽  
Helen Leonard ◽  
Peter G. Parsons ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Tumor Cells ◽  
Histone Deacetylase ◽  
Cell Cycle Progression ◽  
Histone Deacetylase Inhibitors ◽  
Cell Cycle Checkpoint ◽  
Phase Cell ◽  
Selective Toxicity ◽  
Protective Mechanisms ◽  
G2 Checkpoint

Important aspects of cell cycle regulation are the checkpoints, which respond to a variety of cellular stresses to inhibit cell cycle progression and act as protective mechanisms to ensure genomic integrity. An increasing number of tumor suppressors are being demonstrated to have roles in checkpoint mechanisms, implying that checkpoint dysfunction is likely to be a common feature of cancers. Here we report that histone deacetylase inhibitors, in particular azelaic bishydroxamic acid, triggers a G2 phase cell cycle checkpoint response in normal human cells, and this checkpoint is defective in a range of tumor cell lines. Loss of this G2 checkpoint results in the tumor cells undergoing an aberrant mitosis resulting in fractured multinuclei and micronuclei and eventually cell death. This histone deacetylase inhibitor-sensitive checkpoint appears to be distinct from G2/M checkpoints activated by genotoxins and microtubule poisons and may be the human homologue of a yeast G2 checkpoint, which responds to aberrant histone acetylation states. Azelaic bishydroxamic acid may represent a new class of anticancer drugs with selective toxicity based on its ability to target a dysfunctional checkpoint mechanism in tumor cells.

Abstract 502: Inhibition of Histone Deacetylase 6 Protects Human Induced Pluripotent Stem Cells-derived Cardiomyocytes Through Inhibition of Autophagy

2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Narasimman Gurusamy ◽  
SHEEJA RAJASINGH ◽  
Vinoth Sigamani ◽  
Shivaani Kirankumar ◽  
Jayavardini Vasanthan ◽  
...  
Keyword(s):  
Stem Cells ◽  
Angiotensin Ii ◽  
Cardiac Hypertrophy ◽  
Induced Pluripotent Stem Cells ◽  
Histone Deacetylase ◽  
Pluripotent Stem Cells ◽  
Histone Deacetylase 6 ◽  
Hdac6 Inhibitor ◽  
Induced Pluripotent ◽  
First Time

Introduction: Autophagy is known to play an important role in mediating cardiac hypertrophy. However, the mechanism is poorly understood. Since the protein histone deacetylase 6 (HDAC6) contributes to cardiac dysfunction in response to angiotensin II (AngII) signaling, we have examined the role of HDAC6 inhibitor tubastatin A (TBA) in AngII-induced remodeling in human induced pluripotent stem cells-derived cardiomyocytes (iCMCs). Hypothesis: We hypothesize that the inhibition of HDAC6 protects iCMCs from AngII-induced cardiac hypertrophy through inhibition of autophagy. Methods and Results: We have generated and characterized induced pluripotent stem cells from human adult skin fibroblasts and subsequently differentiated them into iCMCs. Treatment with 10 μM angiotensin II for 24 hrs increased the HDAC6 activity and lead to hypertrophy in iCMCs. The AngII-induced hypertrophy, and the excessive contractility in iCMCs were reversed by the inhibition of HDAC6 with TBA (1 μM for 24 hours). The number of LC3-positive iCMCs, and the mRNA and the protein expression of autophagic genes Beclin-1, LC3, and p62 were increased by the presence of AngII, and the anti-autophagic gene Bcl2 was decreased by AngII. The inhibition of HDAC6 with TBA reversed the AngII-mediated changes in the autophagic genes expressions in iCMCs. Autophagic vacuoles were identified with monodansylcadaverine (MDC, green) and lysosomes with LysoTracker (red) (Fig. 1A) . The number of autophagolysosomes were increased by AngII, and this was decreased with TBA in iCMCs (Fig. 1B) . Conclusions: Our report indicates for the first time that the AngII-induced cardiac hypertrophy-mediated autophagy is effectively inhibited by the suppression of HDAC6 in human iCMCs.

scholarly journals Oncogenic ras and p53 Cooperate To Induce Cellular Senescence

2002 ◽  
Vol 22 (10) ◽  
pp. 3497-3508 ◽  
Author(s):  
Gerardo Ferbeyre ◽  
Elisa de Stanchina ◽  
Athena W. Lin ◽  
Emmanuelle Querido ◽  
Mila E. McCurrach ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Map Kinase ◽  
Cell Cycle Arrest ◽  
Cellular Senescence ◽  
Null Mouse ◽  
P53 Expression ◽  
Oncogenic Ras ◽  
Cycle Arrest ◽  
Murine Fibroblasts ◽  
Mitogen Activated Protein

ABSTRACT Oncogenic activation of the mitogen-activated protein (MAP) kinase cascade in murine fibroblasts initiates a senescence-like cell cycle arrest that depends on the ARF/p53 tumor suppressor pathway. To investigate whether p53 is sufficient to induce senescence, we introduced a conditional murine p53 allele (p53val135 ) into p53-null mouse embryonic fibroblasts and examined cell proliferation and senescence in cells expressing p53, oncogenic Ras, or both gene products. Conditional p53 activation efficiently induced a reversible cell cycle arrest but was unable to induce features of senescence. In contrast, coexpression of oncogenic ras or activated mek1 with p53 enhanced both p53 levels and activity relative to that observed for p53 alone and produced an irreversible cell cycle arrest that displayed features of cellular senescence. p19ARF was required for this effect, since p53 −/− ARF −/− double-null cells were unable to undergo senescence following coexpression of oncogenic Ras and p53. Although the levels of exogenous p53 achieved in ARF-null cells were relatively low, the stabilizing effects of p19ARF on p53 could not explain the cooperation between oncogenic Ras and p53 in promoting senescence. Hence, enforced p53 expression without oncogenic ras in p53 −/− mdm2 −/− double-null cells produced extremely high p53 levels but did not induce senescence. Taken together, our results indicate that oncogenic activation of the MAP kinase pathway in murine fibroblasts converts p53 into a senescence inducer through both quantitative and qualitative mechanisms.

scholarly journals Histone Deacetylase Inhibitors Down-Regulate bcl-2 Expression and Induce Apoptosis in t(14;18) Lymphomas

2005 ◽  
Vol 25 (5) ◽  
pp. 1608-1619 ◽  
Author(s):  
Hong Duan ◽  
Caroline A. Heckman ◽  
Linda M. Boxer
Keyword(s):  
Cell Cycle ◽  
Histone Deacetylase ◽  
Chromatin Immunoprecipitation ◽  
Histone Deacetylase Inhibitors ◽  
Antitumor Agents ◽  
Trichostatin A ◽  
Hdac Inhibitors ◽  
Transcriptional Level ◽  
Cycle Arrest ◽  
Induced Apoptosis

ABSTRACT Histone deacetylase (HDAC) inhibitors are promising antitumor agents, but they have not been extensively explored in B-cell lymphomas. Many of these lymphomas have the t(14;18) translocation, which results in increased bcl-2 expression and resistance to apoptosis. In this study, we examined the effects of two structurally different HDAC inhibitors, trichostatin A (TSA) and sodium butyrate (NaB), on the cell cycle, apoptosis, and bcl-2 expression in t(14;18) lymphoma cells. We found that in addition to potent cell cycle arrest, TSA and NaB also dramatically induced apoptosis and down-regulated bcl-2 expression, and overexpression of bcl-2 inhibited TSA-induced apoptosis. The repression of bcl-2 by TSA occurred at the transcriptional level. Western blot analysis and quantitative chromatin immunoprecipitation (ChIP) assay showed that even though HDAC inhibitors increased overall acetylation of histones, localized histone H3 deacetylation occurred at both bcl-2 promoters. TSA treatment increased the acetylation of the transcription factors Sp1 and C/EBPα and decreased their binding as well as the binding of CBP and HDAC2 to the bcl-2 promoters. Mutation of Sp1 and C/EBPα binding sites reduced the TSA-induced repression of bcl-2 promoter activity. This study provides a mechanistic rationale for the use of HDAC inhibitors in the treatment of human t(14;18) lymphomas.

Abstract 1884: Dual targeting of cell cycle checkpoint and histone deacetylase overcomes bortezomib resistance in multiple myeloma

2018 ◽  
Author(s):  
Takayuki Tabayashi ◽  
Yuka Tanaka ◽  
Yasuyuki Takahashi ◽  
Yuta Kimura ◽  
Tatsuki Tomikawa ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Multiple Myeloma ◽  
Histone Deacetylase ◽  
Cell Cycle Checkpoint ◽  
Dual Targeting ◽  
Cycle Checkpoint
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