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Antiviral Research May 2021Romidepsin, a histone deacetylase (HDAC) inhibitor, has been approved for the treatment of relapsed and refractory peripheral T-cell lymphoma. However the use of...
Sildenafil prevents HDACi-induced Epstein-Barr virus reactivation through the PKG pathway in NK/T cell lymphoma; potential implications for HDACi-mediated fatal complications.
Romidepsin, a histone deacetylase (HDAC) inhibitor, has been approved for the treatment of relapsed and refractory peripheral T-cell lymphoma. However the use of romidepsin reportedly causes potent EBV (Epstein-Barr virus) reactivation leading to severe adverse events in patients with natural killer (NK)/T-cell lymphoma (NKTL). As inhibition of EBV lytic cycle reactivation may help prevent romidepsin-induced adverse events in NKTL, we herein set out to identify a safe and effective drug for inhibiting EBV reactivation and examine its mechanism of inhibition. EBV reactivation was evaluated by qRT-PCR of BZLF1 and BRLF1 mRNA expression, qPCR of EBV DNA, and immunoblotting of viral EA-D protein. High-throughput screening of FDA-approved drugs was performed to identify safe and effective molecules and test their effect on romidepsin-induced EBV reactivation in the EBV-positive NKTL cell lines, SNK6 and NK92MI. We found that phosphodiesterase 5 (PDE5) inhibitors, including sildenafil (Viagra; Pfizer), appeared to be nontoxic and effective inhibitors of romidepsin-induced EBV reactivation. Clinical relevance was investigated by qPCR of EBV in two primary effusion samples of NKTL patients. We also investigated the molecular consequences downstream of sildenafil-induced PDE5 inhibition in NKTL cells. A negative correlation was established between the cGMP/PKG pathway and EBV reactivation in NKTL cells. On a molecular level, PDE5 inhibition downregulates BZLF1 and BRLF1 through cGMP/PKG signaling-induced ZNF overexpression. Co-treatment with romidepsin and sildenafil (inhibiting HDAC and PDE5, respectively) showed a synergistic inhibitory effect on NKTL cells, highlighting PDE5 as an attractive target for future therapy in NKTL.
Topics: Antibiotics, Antineoplastic; Cell Line, Tumor; Cyclic GMP-Dependent Protein Kinases; Cyclic Nucleotide Phosphodiesterases, Type 5; DNA, Viral; Depsipeptides; Down-Regulation; Enzyme Inhibitors; Epstein-Barr Virus Infections; Gene Expression Regulation, Neoplastic; Gene Expression Regulation, Viral; Herpesvirus 4, Human; Histone Deacetylase Inhibitors; Humans; Immediate-Early Proteins; Lymphoma, T-Cell; Phosphodiesterase 5 Inhibitors; Signal Transduction; Sildenafil Citrate; Trans-Activators; Virus Activation; Zinc Fingers
PubMed: 33741394
DOI: 10.1016/j.antiviral.2021.105063 -
Cancer Immunology, Immunotherapy : CII Jan 2021Romidepsin (FK228), a histone deacetylase inhibitor (HDACi), has anti-tumor effects against several types of solid tumors. Studies have suggested that HDACi could...
Romidepsin (FK228), a histone deacetylase inhibitor (HDACi), has anti-tumor effects against several types of solid tumors. Studies have suggested that HDACi could upregulate PD-L1 expression in tumor cells and change the state of anti-tumor immune responses in vivo. However, the influence of enhanced PD-L1 expression in tumor cells induced by romidepsin on anti-tumor immune responses is still under debate. So, the purpose of this study was to explore the anti-tumor effects and influence on immune responses of romidepsin in colon cancer. The results indicated that romidepsin inhibited proliferation, induced G0/G1 cell cycle arrest and increased apoptosis in CT26 and MC38 cells. Romidepsin treatment increased PD-L1 expression in vivo and in vitro via increasing the acetylation levels of histones H3 and H4 and regulating the transcription factor BRD4. In subcutaneous transplant tumor mice and colitis-associated cancer (CAC) mice, romidepsin increased the percentage of FOXP3+ regulatory T cells (Tregs), decreased the ratio of Th1/Th2 cells and the percentage of IFN-γ+ CD8+ T cells in the peripheral blood and the tumor microenvironment. Upon combination with an anti-PD-1 antibody, the anti-tumor effects of romidepsin were enhanced and the influence on CD4+ and CD8+ T cells was partially reversed. Therefore, the combination of romidepsin and anti-PD-1 immunotherapy provides a more potential treatment for colon cancer.
Topics: Animals; Apoptosis; B7-H1 Antigen; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Colonic Neoplasms; Depsipeptides; Female; G1 Phase; Gene Expression Regulation, Neoplastic; Histones; Immunity, Cellular; Immunotherapy; Ligands; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Resting Phase, Cell Cycle; T-Lymphocytes; Transcription Factors; Tumor Microenvironment
PubMed: 32632663
DOI: 10.1007/s00262-020-02653-1 -
The Journal of Investigative Dermatology Jan 2022HDAC inhibitors show therapeutic promise for skin malignancies; however, the roles of specific HDACs in adult epidermal homeostasis and in disease are poorly understood....
HDAC inhibitors show therapeutic promise for skin malignancies; however, the roles of specific HDACs in adult epidermal homeostasis and in disease are poorly understood. We find that homozygous epidermal codeletion of Hdac1 and Hdac2 in adult mouse epidermis causes reduced basal cell proliferation, apoptosis, inappropriate differentiation, and eventual loss of Hdac1/2-null keratinocytes. Hdac1/2-deficient epidermis displays elevated acetylated p53 and increased expression of the senescence gene p16. Loss of p53 partially restores basal proliferation, whereas p16 deletion promotes long-term survival of Hdac1/2-null keratinocytes. In activated GLI2-driven pre-basal cell carcinoma, Hdac1/2 deletion dramatically reduces proliferation and increases apoptosis, and knockout of either p53 or p16 partially rescues both proliferation and basal cell viability. Topical application of the HDAC inhibitor romidepsin to the normal epidermis or to GLI2ΔN-driven lesions produces similar defects to those caused by genetic Hdac1/2 deletion, and these are partially rescued by loss of p16. These data reveal essential roles for HDAC1/2 in maintaining proliferation and survival of adult epidermal and basal cell carcinoma progenitors and suggest that the efficacy of therapeutic HDAC1/2 inhibition will depend in part on the mutational status of p53 and p16.
Topics: Animals; Antibiotics, Antineoplastic; Apoptosis; Carcinogenesis; Carcinoma, Basal Cell; Cell Differentiation; Cell Line, Tumor; Cell Proliferation; Cyclin-Dependent Kinase Inhibitor p16; Depsipeptides; Epidermis; Histone Deacetylase 1; Histone Deacetylase 2; Humans; Keratinocytes; Mice; Mice, Inbred C57BL; Mice, Knockout; Precancerous Conditions; Skin Neoplasms; Tumor Suppressor Protein p53
PubMed: 34284046
DOI: 10.1016/j.jid.2021.05.026 -
Journal of Virology Feb 2022While combination antiretroviral therapy maintains undetectable viremia in people living with HIV (PLWH), a lifelong treatment is necessary to prevent viremic rebound...
While combination antiretroviral therapy maintains undetectable viremia in people living with HIV (PLWH), a lifelong treatment is necessary to prevent viremic rebound after therapy cessation. This rebound seemed mainly caused by long-lived HIV-1 latently infected cells reverting to a viral productive status. Reversing latency and elimination of these cells by the so-called shock-and-kill strategy is one of the main investigated leads to achieve an HIV-1 cure. Small molecules referred to as latency reversal agents (LRAs) proved to efficiently reactivate latent CD4 T cells. However, the LRA impact on infection or HIV-1 production in productively infected macrophages remains elusive. Nontoxic doses of bryostatin-1, JQ1, and romidepsin were investigated in human monocyte-derived macrophages (MDMs). Treatment with bryostatin-1 or romidepsin resulted in a downregulation of CD4 and CCR5 receptors, respectively, accompanied by a reduction of R5 tropic virus infection. HIV-1 replication was mainly regulated by receptor modulation for bryostatin-1, while romidepsin effects rely on upregulation of SAMHD1 activity. LRA stimulation of chronically infected cells did not enhance HIV-1 production or gene expression. Surprisingly, bryostatin-1 caused a major decrease in viral production. This effect was not viral strain specific but appears to occur only in myeloid cells. Bryostatin-1 treatment of infected MDMs led to decreased amounts of capsid and matrix mature proteins with little to no modulation of precursors. Our observations revealed that bryostatin-1-treated myeloid and CD4 T cells respond differently upon HIV-1 infection. Therefore, additional studies are warranted to more fully assess the efficiency of HIV-1 eradicating strategies. HIV-1 persists in a cellular latent form despite therapy that quickly propagates infection upon treatment interruption. Reversing latency would contribute to eradicate these cells, closing the gap to a cure. Macrophages are an acknowledged HIV-1 reservoir during therapy and are suspected to harbor latency establishment . However, the impact of latency reversal agents (LRAs) on HIV-1 infection and viral production in human macrophages is poorly known but nonetheless crucial to probe the safety of this strategy. In this study, we discovered encouraging antireplicative features of distinct LRAs in human macrophages. We also described a new viral production inhibition mechanism by protein kinase C agonists that is specific to myeloid cells. This study provides new insights into HIV-1 propagation restriction potentials by LRAs in human macrophages and underline the importance of assessing latency reversal strategy on all HIV-1-targeted cells.
Topics: Anti-HIV Agents; Bryostatins; CD4 Antigens; CD4-Positive T-Lymphocytes; Depsipeptides; Diterpenes; HIV Core Protein p24; HIV-1; Humans; Macrophages; Receptors, CCR5; SAM Domain and HD Domain-Containing Protein 1; Virus Activation; Virus Latency; Virus Replication
PubMed: 34878918
DOI: 10.1128/JVI.01953-21 -
PLoS Pathogens Sep 2018Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiologic agent of three human malignancies, the endothelial cell cancer Kaposi's sarcoma, and two B cell cancers,...
Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiologic agent of three human malignancies, the endothelial cell cancer Kaposi's sarcoma, and two B cell cancers, Primary Effusion Lymphoma and multicentric Castleman's disease. KSHV has latent and lytic phases of the viral life cycle, and while both contribute to viral pathogenesis, lytic proteins contribute to KSHV-mediated oncogenesis. Reactivation from latency is driven by the KSHV lytic gene transactivator RTA, and RTA transcription is controlled by epigenetic modifications. To identify host chromatin-modifying proteins that are involved in the latent to lytic transition, we screened a panel of inhibitors that target epigenetic regulatory proteins for their ability to stimulate KSHV reactivation. We found several novel regulators of viral reactivation: an inhibitor of Bmi1, PTC-209, two additional histone deacetylase inhibitors, Romidepsin and Panobinostat, and the bromodomain inhibitor (+)-JQ1. All of these compounds stimulate lytic gene expression, viral genome replication, and release of infectious virions. Treatment with Romidepsin, Panobinostat, and PTC-209 induces histone modifications at the RTA promoter, and results in nucleosome depletion at this locus. Finally, silencing Bmi1 induces KSHV reactivation, indicating that Bmi1, a member of the Polycomb repressive complex 1, is critical for maintaining KSHV latency.
Topics: Cell Line; Chromatin Assembly and Disassembly; Depsipeptides; Epigenesis, Genetic; Genome, Viral; Herpesvirus 8, Human; Heterocyclic Compounds, 2-Ring; Histone Deacetylase Inhibitors; Host-Pathogen Interactions; Humans; Immediate-Early Proteins; Panobinostat; Polycomb Repressive Complex 1; Promoter Regions, Genetic; RNA Interference; Thiazoles; Trans-Activators; Virus Activation; Virus Latency
PubMed: 30212584
DOI: 10.1371/journal.ppat.1007267 -
BioRxiv : the Preprint Server For... Nov 2023Although few resistance mechanisms for histone deacetylase inhibitors (HDACis) have been described, we recently demonstrated that TMT1A (formerly METTL7A) and TMT1B...
Although few resistance mechanisms for histone deacetylase inhibitors (HDACis) have been described, we recently demonstrated that TMT1A (formerly METTL7A) and TMT1B (formerly METTL7B) can mediate resistance to HDACis with a thiol as the zinc-binding group by methylating and inactivating the drug. TMT1A and TMT1B are poorly characterized, and their normal physiological role has yet to be determined. As animal model systems are often used to determine the physiological function of proteins, we investigated whether the ability of these methyltransferases to methylate thiol-based HDACis is conserved across different species. We found that TMT1A was conserved across rats, mice, chickens, and zebrafish, displaying 85.7%, 84.8%, 60.7% and 51.0% amino acid sequence identity, respectively, with human TMT1A. Because TMT1B was not found in the chicken or zebrafish, we focused our studies on the TMT1A homologs. HEK-293 cells were transfected to express mouse, rat, chicken, or zebrafish homologs of TMT1A and all conferred resistance to the thiol-based HDACIs NCH-51, KD-5170 and romidepsin compared to empty vector-transfected cells. Additionally, all homologs blunted the downstream effects of HDACi treatment such as increased p21 expression, increased acetylated histone H3, and cell cycle arrest. Increased levels of dimethylated romidepsin were also found in the culture medium of cells transfected to express any of the TMT1A homologs after a 24 h incubation with romidepsin compared to empty-vector transfected cells. Our results indicate that the ability of TMT1A to methylate molecules is conserved across species. Animal models may therefore be useful in elucidating the role of these enzymes in humans.
PubMed: 38076968
DOI: 10.1101/2023.11.17.567538 -
Asian Pacific Journal of Cancer... Jan 2023Quantitative profiling of specific cell surface markers is a new approach in characterization of tumor heterogeneity and single cell biology. The current tools have...
BACKGROUND
Quantitative profiling of specific cell surface markers is a new approach in characterization of tumor heterogeneity and single cell biology. The current tools have dearth in detection and quantification of receptor proteins on single cells.
METHODS
we focused on our newly developed protocol to determine the distribution pattern and density of cell surface markers on single acute myeloid leukemia cells. Cell surface proteins were labeled with quantum dots (Qdots) followed by super resolution Structured Illumination Microscopy (SIM) imaging to imprisonment the optical signals emitted by Qdots which were further analyzed by software imaris to do three dimensional (3D) structure reconstruction and digital simulation. Furthermore, MTT assays and flow cytometry was performed to establish association between expression of cell surface markers and drug response.
RESULTS
In the present study, we found that the Molm13 and cytarabine-enriched Molm13 cells exhibit different densities of CD123, an alpha-subunit of interleukin-3 receptor, i.e. 0.92 and 1.73 per μm2 of cell surface respectively. Sub-populations of Molm13 cells expressing higher densities of CD123 on cells membranes showed resistance against cytarabine. Further study revealed that romidepsin sensitized and augmented the cytotoxicity of cytarabine in Molm13 and cytarabine-enriched Molm13 cells. Romidepsin increased the percentage of cell death-induced by cytarabine from 21.6 % to 28.6 % and 37.1 % to 57.2 % in Molm13 and cytarabine-enriched Molm13 cells respectively.
CONCLUSION
Altogether, the study suggests that Molm13 cells have sub-populations with differential expression of CD123+ phenotype. Romidepsin sensitizes and augments the effect of cytarabine in Molm13 and cytarabine-enriched Molm13 cells.
Topics: Humans; Receptors, Interleukin-3; Interleukin-3 Receptor alpha Subunit; Leukemia, Myeloid, Acute; Cytarabine; Flow Cytometry; Cell Line, Tumor
PubMed: 36708567
DOI: 10.31557/APJCP.2023.24.1.185 -
Journal of Virus Eradication Sep 2019To test the potential of fimepinostat (CUDC-907), a dual inhibitor of histone deacetylases (HDAC) and phosphatidylinositol-3-kinases (PI3K), to reverse human...
OBJECTIVES
To test the potential of fimepinostat (CUDC-907), a dual inhibitor of histone deacetylases (HDAC) and phosphatidylinositol-3-kinases (PI3K), to reverse human immunodeficiency virus type 1 (HIV-1) latency in infected cell lines and in CD4+ T cells from HIV-1-infected donors on long-term combination antiretroviral therapy (cART).
METHODS
Latently HIV-1-infected J-lat Tat-GFP and ACH-2 cell lines were stimulated with clinically relevant concentrations of fimepinostat using the HDAC inhibitors (HDACi) panobinostat and romidepsin for comparison. Next, CD4+ T cells from donors living with HIV-1 on long-term cART were stimulated and cell-associated unspliced HIV-1 RNA was measured to quantify changes in HIV-1 transcription. Finally, the impact of fimepinostat on T cell activation (CD69 expression) and proliferation (Ki67 expression) was determined using peripheral blood mononuclear cells from uninfected donors.
RESULTS
We found fimepinostat to be a potent latency-reversing agent. This was true in two latently infected cell lines as well as in CD4+ T cells isolated from donors living with HIV-1. Relative to therapeutic dosing levels, fimepinostat showed latency-reversing potential comparable to romidepsin, which is the most potent HDACi tested in HIV-1 cure-related trials. Interestingly, in contrast to romidepsin, fimepinostat stimulation resulted in decreased T cell activation and had no negative impact on T cell proliferation.
CONCLUSIONS
At therapeutic concentration, the dual HDAC and PI3K inhibitor fimepinostat was a potent HIV-1 latency-reversing agent and it did not induce T cell activation and proliferation. The potential of fimepinostat as a latency-reversing agent warrants further investigation.
PubMed: 31700655
DOI: No ID Found -
Antioxidants & Redox Signaling Jul 2015The contribution of epigenetic alterations to cancer development and progression is becoming increasingly clear, prompting the development of epigenetic therapies.... (Review)
Review
SIGNIFICANCE
The contribution of epigenetic alterations to cancer development and progression is becoming increasingly clear, prompting the development of epigenetic therapies. Histone deacetylase inhibitors (HDIs) represent one of the first classes of such therapy. Two HDIs, Vorinostat and Romidepsin, are broad-spectrum inhibitors that target multiple histone deacetylases (HDACs) and are FDA approved for the treatment of cutaneous T-cell lymphoma. However, the mechanism of action and the basis for the cancer-selective effects of these inhibitors are still unclear.
RECENT ADVANCES
While the anti-tumor effects of HDIs have traditionally been attributed to their ability to modify gene expression after the accumulation of histone acetylation, recent studies have identified the effects of HDACs on DNA replication, DNA repair, and genome stability. In addition, the HDIs available in the clinic target multiple HDACs, making it difficult to assign either their anti-tumor effects or their associated toxicities to the inhibition of a single protein. However, recent studies in mouse models provide insights into the tissue-specific functions of individual HDACs and their involvement in mediating the effects of HDI therapy.
CRITICAL ISSUES
Here, we describe how altered replication contributes to the efficacy of HDAC-targeted therapies as well as discuss what knowledge mouse models have provided to our understanding of the specific functions of class I HDACs, their potential involvement in tumorigenesis, and how their disruption may contribute to toxicities associated with HDI treatment.
FUTURE DIRECTIONS
Impairment of DNA replication by HDIs has important therapeutic implications. Future studies should assess how best to exploit these findings for therapeutic gain.
Topics: Acetylation; Animals; Chromatin; DNA Repair; DNA Replication; Depsipeptides; Histone Deacetylase Inhibitors; Histone Deacetylases; Humans; Hydroxamic Acids; Neoplasms; Vorinostat
PubMed: 24730655
DOI: 10.1089/ars.2014.5915 -
International Journal of Molecular... Jul 2021Neurotrophins and their receptors are relevant factors in controlling neuroblastoma growth and progression. The histone deacetylase (HDAC) inhibitor valproic acid (VPA)...
Neurotrophins and their receptors are relevant factors in controlling neuroblastoma growth and progression. The histone deacetylase (HDAC) inhibitor valproic acid (VPA) has been shown to downregulate TrkB and upregulate the p75NTR/sortilin receptor complex. In the present study, we investigated the VPA effect on the expression of the neurotrophin-3 (NT-3) receptor TrkC, a favorable prognostic marker of neuroblastoma. We found that VPA induced the expression of both full-length and truncated (TrkC-T1) isoforms of TrkC in human neuroblastoma cell lines without (SH-SY5Y) and with (Kelly, BE(2)-C and IMR 32) amplification. VPA enhanced cell surface expression of the receptor and increased Akt and ERK1/2 activation by NT-3. The HDAC inhibitors entinostat, romidepsin and vorinostat also increased TrkC in SH-SY5Y, Kelly and BE(2)-C but not IMR 32 cells. TrkC upregulation by VPA involved induction of RUNX3, stimulation of ERK1/2 and JNK, and ERK1/2-mediated Egr1 expression. In SH-SY5Y cell monolayers and spheroids the exposure to NT-3 enhanced the apoptotic cascade triggered by VPA. Gene silencing of both TrkC-T1 and p75NTR prevented the NT-3 proapoptotic effect. Moreover, NT-3 enhanced p75NTR/TrkC-T1 co-immunoprecipitation. The results indicate that VPA upregulates TrkC by activating epigenetic mechanisms and signaling pathways, and sensitizes neuroblastoma cells to NT-3-induced apoptosis.
Topics: Anticonvulsants; Apoptosis; Cell Proliferation; Gene Expression Regulation, Neoplastic; Humans; Molecular Targeted Therapy; Neuroblastoma; Receptor, trkC; Tumor Cells, Cultured; Valproic Acid
PubMed: 34360553
DOI: 10.3390/ijms22157790