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Because of synergism between tubulin and HDAC inhibitors, we used the pharmacophore fusion strategy to generate potential tubulin-HDAC dual inhibitors. Drug design was based on the introduction of a N-hydroxyacrylamide or a N-hydroxypropiolamide at the 5-position of the 2-aroylbenzo[b]furan skeleton, to produce compounds 6a-i and 11a-h, respectively. Among the synthesized compounds, derivatives 6a, 6c, 6e, 6g, 11a, and 11c showed excellent antiproliferative activity, with IC50 values at single- or double-digit nanomolar levels, against the A549, HT-29, and MCF-7 cells resistant towards the control compound combretastatin A-4 (CA-4). Compounds 11a and 6g were also 10-fold more active than CA-4 against the Hela cell line. When comparing the inhibition of tubulin polymerization versus the HDAC6 inhibitory activity, we found that 6a-g, 6i, 11a, 11c, and 11e, although very potent as inhibitors of tubulin assembly, did not have significant inhibitory activity against HDAC6.
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Antineoplásicos , Benzofuranos , Proliferación Celular , Ácidos Hidroxámicos , Moduladores de Tubulina , Tubulina (Proteína) , Humanos , Benzofuranos/farmacología , Benzofuranos/química , Benzofuranos/síntesis química , Moduladores de Tubulina/farmacología , Moduladores de Tubulina/síntesis química , Moduladores de Tubulina/química , Ácidos Hidroxámicos/farmacología , Ácidos Hidroxámicos/química , Ácidos Hidroxámicos/síntesis química , Tubulina (Proteína)/metabolismo , Antineoplásicos/farmacología , Antineoplásicos/síntesis química , Antineoplásicos/química , Proliferación Celular/efectos de los fármacos , Inhibidores de Histona Desacetilasas/farmacología , Inhibidores de Histona Desacetilasas/síntesis química , Inhibidores de Histona Desacetilasas/química , Células HeLa , Histona Desacetilasa 6/antagonistas & inhibidores , Histona Desacetilasa 6/metabolismo , Línea Celular Tumoral , Células MCF-7 , Relación Estructura-Actividad , Ensayos de Selección de Medicamentos Antitumorales , Células HT29RESUMEN
The infusions prepared from some Quercus L. species are used in folk medicine for medicinal purposes and consumed as tea. Quercus pontica K. Koch was selected in this study, for which no phytochemical isolation studies have been performed so far. Quercetin 3-O- ß-D-glucopyranoside, kaempferol 3-O-(6""-O-galloyl)-ß-D-glucopyranoside, kaempferol 3-O-ß-D-glucopyranoside, kaempferol 3-O-(6"'-coumaroyl-ß-D-glucopyranoside, phlorizin, rosmarinic acid, and catechin were isolated from the titled plant for the first time. Some polyphenolic compounds have been shown to inhibit histone deacetylase (HDAC) enzymes. However, there is no study on the any activities of Quercus species in the literature. In this study, we demonstrated that the extract has in vitro pan-HDAC inhibition activity. Through a virtual screening study, the compounds were found to inhibit HDAC7 more strongly than the other HDAC isoforms; therefore, the HDAC7 inhibition activities were studied in vitro. Kaempferol 3-O-ß-D-glucopyranoside and kaempferol 3-O-(6'"-coumaroyl-ß-D-glucopyranoside) showed the best anti-HDAC7 activity with 37% and 41% inhibition at 500 µM.
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Collectively known as psoriatic disease, psoriasis and psoriatic arthritis (PsA) are immune-mediated inflammatory diseases in which patients present with cutaneous and musculoskeletal inflammation. Affecting roughly 2-3% of the world's total population, there remains unmet therapeutic needs in both psoriasis and PsA despite the availability of current immunomodulatory treatments. As a result, patients with psoriatic disease often experience reduced quality of life. Recently, a class of small molecules, commonly investigated as anti-cancer agents, called histone deacetylase (HDAC) inhibitors, have been proposed as a new promising anti-inflammatory treatment for immune- and inflammatory-related diseases. In inflammatory diseases, current evidence is derived from studies on diseases like rheumatoid arthritis (RA) and systematic lupus erythematosus (SLE), and while there are some reports studying psoriasis, data on PsA patients are not yet available. In this review, we provide a brief overview of psoriatic disease, psoriasis, and PsA, as well as HDACs, and discuss the rationale behind the potential use of HDAC inhibitors in the management of persistent inflammation to suggest its possible use in psoriatic disease.
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Artritis Psoriásica , Psoriasis , Humanos , Artritis Psoriásica/tratamiento farmacológico , Inhibidores de Histona Desacetilasas/uso terapéutico , Inflamación/tratamiento farmacológico , Psoriasis/tratamiento farmacológico , Calidad de VidaRESUMEN
The treatment of human immunodeficiency virus (HIV) infection is notoriously difficult due to the ability of this virus to remain latent in the host's CD4+ T cells. Histone deacetylases (HDACs) interfere with DNA transcription in HIV-infected hosts, resulting in viral latency. Therefore, HDAC inhibitors can be used to activate viral transcription in latently infected cells, after which the virus can be eliminated through a shock-and-kill strategy. Here, a drug delivery system is developed to effectively deliver HDAC inhibitors to latent HIV-infected cells. Given that the efficacy of HDAC inhibitors is reduced under hypoxic conditions, oxygen-containing nanosomes are used as drug carriers. Oxygen-containing nanosomes can improve the efficiency of chemotherapy by delivering essential oxygen to cells. Additionally, their phospholipid bilayer structure makes them uniquely well-suited for drug delivery. In this study, a novel drug delivery system is developed by taking advantage of the oxygen carriers in these oxygen nanosomes, incorporating a multi-drug strategy consisting of HDAC inhibitors and PKA activators, and introducing CXCR4 binding peptides to specifically target CD4+ T cells. Oxygen nanosomes with enhanced targeting capability through the introduction of the CXCR4 binding peptide mitigate drug toxicity and slow down drug release. The observed changes in the expression of p24, a capsid protein of HIV, indirectly confirm that the proposed drug delivery system can effectively induce transcriptional reactivation of HIV in latent HIV-infected cells.
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Infecciones por VIH , VIH-1 , Humanos , Inhibidores de Histona Desacetilasas/farmacología , Inhibidores de Histona Desacetilasas/uso terapéutico , Latencia del Virus , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/genética , Oxígeno/farmacología , Linfocitos T CD4-Positivos , VIH-1/genéticaRESUMEN
For many years, antibody drug conjugates (ADC) have teased with the promise of targeted payload delivery to diseased cells, embracing the targeting of the antibody to which a cytotoxic payload is conjugated. During the past decade this promise has started to be realised with the approval of more than a dozen ADCs for the treatment of various cancers. Of these ADCs, brentuximab vedotin really laid the foundations of a template for a successful ADC with lysosomal payload release from a cleavable dipeptide linker, measured DAR by conjugation to the Cys-Cys interchain bonds of the antibody and a cytotoxic payload. Using this ADC design model oncology has now expanded their repertoire of payloads to include non-cytotoxic compounds. These new payload classes have their origins in prior medicinal chemistry programmes aiming to design selective oral small molecule drugs. While this may not have been achieved, the resulting compounds provide excellent starting points for ADC programmes with some compounds amenable to immediate linker attachment while for others extensive SAR and structural information offer invaluable design insights. Many of these new oncology payload classes are of interest to other therapeutic areas facilitating rapid access to drug-linkers for exploration as non-oncology ADCs. Other therapeutic areas have also pursued unique payload classes with glucocorticoid receptor modulators (GRM) being the most clinically advanced in immunology. Here, ADC payloads come full circle, as oncology is now investigating GRM payloads for the treatment of cancer. This chapter aims to cover all these new ADC approaches while describing the medicinal chemistry origins of the new non-cytotoxic payloads.
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Antineoplásicos , Inmunoconjugados , Neoplasias , Humanos , Inmunoconjugados/farmacología , Inmunoconjugados/uso terapéutico , Antineoplásicos/farmacología , Antineoplásicos/química , Brentuximab Vedotina , Neoplasias/tratamiento farmacológicoRESUMEN
Histone deacetylase (HDAC) 1, a member of the histone deacetylases family, plays a pivotal role in various tumors. In this study, we collected 7313 human HDAC1 inhibitors with bioactivities to form a dataset. Then, the dataset was divided into a training set and a test set using two splitting methods: (1) Kohonen's self-organizing map and (2) random splitting. The molecular structures were represented by MACCS fingerprints, RDKit fingerprints, topological torsions fingerprints and ECFP4 fingerprints. A total of 80 classification models were built by using five machine learning methods, including decision tree (DT), random forest, support vector machine, eXtreme Gradient Boosting and deep neural network. Model 15A_2 built by the XGBoost algorithm based on ECFP4 fingerprints showed the best performance, with an accuracy of 88.08% and an MCC value of 0.76 on the test set. Finally, we clustered the 7313 HDAC1 inhibitors into 31 subsets, and the substructural features in each subset were investigated. Moreover, using DT algorithm we analyzed the structure-activity relationship of HDAC1 inhibitors. It may conclude that some substructures have a significant effect on high activity, such as N-(2-amino-phenyl)-benzamide, benzimidazole, AR-42 analogues, hydroxamic acid with a middle chain alkyl and 4-aryl imidazole with a midchain of alkyl whose α carbon is chiral.
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Algoritmos , Aprendizaje Automático , Humanos , Relación Estructura-Actividad , Estructura Molecular , Máquina de Vectores de Soporte , Histona Desacetilasa 1RESUMEN
Class II histone deacetylases (HDACs) are considered as potential targets to treat Alzheimer's disease (AD). Previously, C-3 substituted phenothiazine-containing compounds with class II HDAC-inhibiting activities was found to promote neurite outgrowth. This study replaced phenothiazine moiety with phenoxazine that contains many C-3 and C-4 substituents. Some resulting compounds bearing the C-4 substituent on a phenoxazine ring displayed potent class II HDAC inhibitory activities. Structure-activity relationship (SAR) of these compounds that inhibited HDAC isoenzymes was disclosed. Molecular modelling analysis demonstrates that the potent activities of C-4 substituted compounds probably arise from π-π stacked interactions between these compounds and class IIa HDAC enzymes. One of these, compound 7d exhibited the most potent class II HDAC inhibition (IC50= 3-870 nM). Notably, it protected neuron cells from H2O2-induced neuron damage at sub-µM concentrations, but with no significant cytotoxicity. These findings show that compound 7d is a lead compound for further development of anti-neurodegenerative agents.
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Antineoplásicos , Ácidos Hidroxámicos , Ácidos Hidroxámicos/farmacología , Inhibidores de Histona Desacetilasas/farmacología , Peróxido de Hidrógeno/farmacología , Relación Estructura-Actividad , Histona Desacetilasas/metabolismo , Antineoplásicos/farmacología , Histona Desacetilasa 1/farmacología , Proliferación CelularRESUMEN
Histone deacetylases (HDACs) are important targets in cancer treatment, and the development of selective and broad-spectrum HDACs inhibitors (HDACis) is urgent. In this research, a series of aroylpiperazine hybrid derivatives were designed and synthesized. Among these, indole-piperazine hybrids 6a (IC50 = 205 nM) and 6b (IC50 = 280 nM) showed submicromolar activity against HDAC1. Moreover, 6a showed a preferable affinity toward class I HDACs, especially for HDAC1-3. In vitro, 6a exhibited better antiproliferative activities against K562 and HCT116 cell lines than chidamide.
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Inhibidores de Histona Desacetilasas , Histona Desacetilasas , Humanos , Células HCT116 , Indoles , PiperazinasRESUMEN
Herein, we report the design, synthesis and evaluation of novel (E)-3-(3-oxo-4-substituted-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl)-N-hydroxypropenamides (4 a-i, 7 a-g) targeting histone deacetylases. Three human cancer cell lines were used to test the cytotoxicity of the synthesized compounds (SW620, colon; PC-3, prostate; NCI-H23, lung cancer); inhibitory activity towards HDAC; anticancer activity; as well as their impact on the cell cycle and apoptosis. As a result, compounds 4 a-i bearing the alkyl substituents seemed to be less potent than the benzyl-containing compounds 7 a-g in all biological assays. Compounds 7 e-f were found to be the most active HDAC inhibitors with IC50 of 1.498±0.020â µM and 1.794±0.159â µM, respectively. In terms of cytotoxicity and anticancer assay, 7 e and 7 f also showed good activity with IC50 values in the micromolar range. In addition, the cell cycle and apoptosis of SW620 were affected by compound 7 f in almost a similar manner to that of reference compound SAHA. Docking assays were carried out for analysis the binding mode and selectivity of this compound toward 8 HDAC isoforms. Overall, our data confirmed that the inhibition of HDAC plays a pivotal role in their anticancer activity.
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Antineoplásicos , Inhibidores de Histona Desacetilasas , Humanos , Inhibidores de Histona Desacetilasas/química , Relación Estructura-Actividad , Antineoplásicos/química , Línea Celular Tumoral , Ácidos Hidroxámicos , Ensayos de Selección de Medicamentos Antitumorales , Proliferación Celular , Diseño de Fármacos , Simulación del Acoplamiento MolecularRESUMEN
In recent years, histone deacetylases (HDACs) have emerged as promising targets in the treatment of cancer. The approach is to inhibit HDACs with drugs known as HDAC inhibitors (HDACis). Such HDACis are broadly classified according to their chemical structure, e.g., hydroxamic acids, benzamides, thiols, short-chain fatty acids, and cyclic peptides. Fluorination plays an important role in the medicinal-chemical design of new active representatives. As a result of the introduction of fluorine into the chemical structure, parameters such as potency or selectivity towards isoforms of HDACs can be increased. However, the impact of fluorination cannot always be clearly deduced. Nevertheless, a change in lipophilicity and, hence, solubility, as well as permeability, can influence the potency. The selectivity towards certain HDACs isoforms can be explained by special interactions of fluorinated compounds with the structure of the slightly different enzymes. Another aspect is that for a more detailed investigation of newly synthesized fluorine-containing active compounds, fluorination is often used for the purpose of labeling. Aside from the isotope 19F, which can be detected by nuclear magnetic resonance spectroscopy, the positron emission tomography of 18F plays a major role. However, to our best knowledge, a survey of the general effects of fluorination on HDACis development is lacking in the literature to date. Therefore, the aim of this review is to highlight the introduction of fluorine in the course of chemical synthesis and the impact on biological activity, using selected examples of recently developed fluorinated HDACis.
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Flúor , Inhibidores de Histona Desacetilasas , Inhibidores de Histona Desacetilasas/farmacología , Halogenación , Histona Desacetilasas/metabolismo , Ácidos Hidroxámicos/química , Isoformas de Proteínas/metabolismoRESUMEN
Saccharomyces cerevisiae exhibits gene expression homeostasis, which is defined as the buffering of transcription levels against changes in DNA copy number during the S phase of the cell cycle. It has been suggested that S. cerevisiae employs an active mechanism to maintain gene expression homeostasis through Rtt109-Asf1-dependent acetylation of histone H3 on lysine 56 (H3K56). Here, we show that gene expression homeostasis can be achieved independently of H3K56 acetylation by Tos4 (Target of Swi6-4). Using Nanostring technology, we establish that Tos4-dependent gene expression homeostasis depends on its forkhead-associated (FHA) domain, which is a phosphopeptide recognition domain required to bind histone deacetylases (HDACs). We demonstrate that the mechanism of Tos4-dependent gene expression homeostasis requires its interaction with the Rpd3L HDAC complex. However, this is independent of Rpd3's well-established roles in both histone deacetylation and controlling the DNA replication timing program, as established by deep sequencing of Fluorescence-Activated Cell Sorted (FACS) S and G2 phase populations. Overall, our data reveals that Tos4 mediates gene expression homeostasis through its FHA domain-dependent interaction with the Rpd3L complex, which is independent of H3K56ac.
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Regulación Fúngica de la Expresión Génica , Histona Acetiltransferasas/metabolismo , Histonas/metabolismo , Homeostasis , Lisina/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Acetilación , Histona Acetiltransferasas/genética , Histonas/genética , Lisina/genética , Procesamiento Proteico-Postraduccional , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crecimiento & desarrollo , Proteínas de Saccharomyces cerevisiae/genéticaRESUMEN
Signal transducer and activator of transcription 3 (STAT3) is an important transcription factor involved in many physiological functions including embryonic development and immune responses and is often activated under pathological conditions such as cancer. Strategies to inactivate STAT3 are being pursued as potential anticancer therapies and have led to the identification of Stattic (6-nitrobenzo[b]thiophene-1,1-dioxide) as a "specific" STAT3 inhibitor that is often used to interrogate STAT3-mediated gene expression in vitro and in vivo. Here, we show that Stattic exerts many STAT3-independent effects on cancer cells, calling for reassessment of results previously ascribed to STAT3 functions. Studies of the STAT3-deficient prostate cancer cell line PC-3 (PC3) along with STAT3-proficient breast cancer cell lines (MDA-MB-231, SUM149) revealed that Stattic attenuated histone acetylation and neutralized effects of the histone deacetylase (HDAC) inhibitor romidepsin. In PC3 cells, Stattic alone inhibited gene expression of CCL20 and CCL2, but activated expression of TNFA, CEBPD, SOX2, and MYC. In addition, we found that Stattic promoted autophagy and caused cell death. These data point to profound epigenetic effects of Stattic that are independent of its function as a STAT3 inhibitor. Our results demonstrate that Stattic directly or indirectly reduces histone acetylation and suggest reevaluation of Stattic and related compounds as polypharmacological agents through multipronged cytotoxic effects on cancer cells.
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Antineoplásicos/farmacología , Óxidos S-Cíclicos/farmacología , Regulación Neoplásica de la Expresión Génica , Histonas/genética , Procesamiento Proteico-Postraduccional , Factor de Transcripción STAT3/genética , Acetilación/efectos de los fármacos , Autofagia/efectos de los fármacos , Autofagia/genética , Proteína delta de Unión al Potenciador CCAAT/agonistas , Proteína delta de Unión al Potenciador CCAAT/genética , Proteína delta de Unión al Potenciador CCAAT/metabolismo , Muerte Celular/efectos de los fármacos , Muerte Celular/genética , Línea Celular Tumoral , Quimiocina CCL2/antagonistas & inhibidores , Quimiocina CCL2/genética , Quimiocina CCL2/metabolismo , Quimiocina CCL20/antagonistas & inhibidores , Quimiocina CCL20/genética , Quimiocina CCL20/metabolismo , Femenino , Genes Reporteros , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Histonas/antagonistas & inhibidores , Histonas/metabolismo , Humanos , Proteínas Luminiscentes/genética , Proteínas Luminiscentes/metabolismo , Masculino , Células PC-3 , Isoformas de Proteínas/antagonistas & inhibidores , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas Proto-Oncogénicas c-myc/agonistas , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , Factores de Transcripción SOXB1/agonistas , Factores de Transcripción SOXB1/genética , Factores de Transcripción SOXB1/metabolismo , Factor de Transcripción STAT3/antagonistas & inhibidores , Factor de Transcripción STAT3/metabolismo , Transducción de Señal , Factor de Necrosis Tumoral alfa/agonistas , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismo , Proteína Fluorescente RojaRESUMEN
The reputation of conventional treatment in acute lymphoblastic leukemia (ALL) has recently been questioned due to the considerable increment in the number of relapsed patients. The remarkable role of histone deacetylase (HDAC) enzymes in induction of chemo-resistance has provided an opportunity for HDAC inhibitors to be used as a treatment strategy in ALL; however, the compensatory activation of oncogenic pathways may negatively affect their promising effects. In the present study, we found an attenuating effect for PI3K axis on the anti-leukemic effects of panobinostat in pre-B ALL-derived Nalm-6 cells, as the harnessing of this pathway using BKM120 or CAL-101 resulted in a significant reduction in the number of viable cells as well as the metabolic activity. Moreover, we found the altered expression of p21, p27, c-Myc, and CDK4 upon co-treatment of the cells with panobinostat and BKM120, which was associated with a substantial blockage of cell cycle progression at G2/M phase. The companionship of the PI3K inhibitor with HDAC inhibitor also potentiated panobinostat-induced apoptotic cell death and enhanced the mRNA of Foxo3a and Foxo4. Conclusively, this study sheds light on the adjuvantive effects of BKM120 on panobinostat efficacy and outlined that the simultaneous inhibition of PI3K and HDACs may be a promising therapeutic approach to improve the cure rates of ALL.
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Antineoplásicos , Fosfatidilinositol 3-Quinasas , Aminopiridinas/farmacología , Antineoplásicos/farmacología , Apoptosis , Línea Celular Tumoral , Histona Desacetilasas/genética , Humanos , Morfolinas , Panobinostat/farmacologíaRESUMEN
INTRODUCTION: Diffuse midline gliomas (DMG) with the H3 K27M-mutation are a well-described entity with most DMG harboring this mutation, with notable heterogeneity in adults. No therapy has been proven to improve survival in this tumor type. Panobinostat is a histone deacetylase inhibitor that may have therapeutic benefit. METHODS: We report our retrospective experience with use of panobinostat in adults (> 18 years) with H3 K27M-mutant DMG treated at Mayo Clinic (Rochester) from January 2016 to August 2020, with follow-up until October 2021. Survival was calculated using the Kaplan-Meier method. RESULTS: 4 patients with H3 K27M-mutant glioma were treated with panobinostat as compassionate use. Patients had a median age of 40 years (range 22-62 years) and 2 were female. Tumor location was midline for all patients, spinal cord (n = 2), brainstem (n = 1), and thalamus (n = 1). All tumors were IDH1/IDH2 wildtype. 3 patients received radiotherapy followed by adjuvant panobinostat. All patients had no other pharmacologic therapy utilized prior to or during panobinostat therapy aside from concurrent dexamethasone utilized in 3 patients. No patient experienced a grade 2 or higher (per CTCAE grade) adverse effect. The median overall survival was 42 months, median progression free survival of 19 months, 2 patients were alive at last follow up (both with spinal cord tumors and received radiation). The best response was stable disease in 2 patients and a partial response in 1 patient. CONCLUSIONS: This is the first report of clinical outcomes of panobinostat in adults with H3 K27M-mutant DMG. We showed that it is well-tolerated at the dosage schedule that we describe, with no serious adverse effects throughout the study period.
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Neoplasias Encefálicas , Glioma , Adulto , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patología , Femenino , Glioma/tratamiento farmacológico , Glioma/genética , Glioma/patología , Histonas/genética , Humanos , Persona de Mediana Edad , Mutación , Panobinostat/uso terapéutico , Estudios Retrospectivos , Adulto JovenRESUMEN
The salt-inducible kinases, SIK1, SIK2 and SIK3, most closely resemble the AMP-activated protein kinase (AMPK) and other AMPK-related kinases, and like these family members they require phosphorylation by LKB1 to be catalytically active. However, unlike other AMPK-related kinases they are phosphorylated by cyclic AMP-dependent protein kinase (PKA), which promotes their binding to 14-3-3 proteins and inactivation. The most well-established substrates of the SIKs are the CREB-regulated transcriptional co-activators (CRTCs), and the Class 2a histone deacetylases (HDAC4/5/7/9). Phosphorylation by SIKs promotes the translocation of CRTCs and Class 2a HDACs to the cytoplasm and their binding to 14-3-3s, preventing them from regulating their nuclear binding partners, the transcription factors CREB and MEF2. This process is reversed by PKA-dependent inactivation of the SIKs leading to dephosphorylation of CRTCs and Class 2a HDACs and their re-entry into the nucleus. Through the reversible regulation of these substrates and others that have not yet been identified, the SIKs regulate many physiological processes ranging from innate immunity, circadian rhythms and bone formation, to skin pigmentation and metabolism. This review summarises current knowledge of the SIKs and the evidence underpinning these findings, and discusses the therapeutic potential of SIK inhibitors for the treatment of disease.
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Ritmo Circadiano , Trastornos Mentales/tratamiento farmacológico , Neoplasias/tratamiento farmacológico , Osteoporosis/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Humanos , Trastornos Mentales/enzimología , Trastornos Mentales/patología , Neoplasias/enzimología , Neoplasias/patología , Osteoporosis/enzimología , Osteoporosis/patologíaRESUMEN
Regenerative medicine represents a growing hot topic in biomedical sciences, aiming at setting out novel therapeutic strategies to repair or regenerate damaged tissues and organs. For this perspective, human mesenchymal stem cells (hMSCs) play a key role in tissue regeneration, having the potential to differentiate into many cell types, including chondrocytes. Accordingly, in the last few years, researchers have focused on several in vitro strategies to optimize hMSC differentiation protocols, including those relying on epigenetic manipulations that, in turn, lead to the modulation of gene expression patterns. Therefore, in the present study, we investigated the role of the class II histone deacetylase (HDAC) inhibitor, MC1568, in the hMSCs-derived chondrogenesis. The hMSCs we used for this work were the hMSCs obtained from the amniotic fluid, given their greater differentiation capacity. Our preliminary data documented that MC1568 drove both the improvement and acceleration of hMSCs chondrogenic differentiation in vitro, since the differentiation process in MC1568-treated cells took place in about seven days, much less than that normally observed, namely 21 days. Collectively, these preliminary data might shed light on the validity of such a new differentiative protocol, in order to better assess the potential role of the epigenetic modulation in the process of the hypertrophic cartilage formation, which represents the starting point for endochondral ossification.
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Condrogénesis , Células Madre Mesenquimatosas , Diferenciación Celular/genética , Células Cultivadas , Condrocitos/metabolismo , Condrogénesis/genética , Epigénesis Genética , Humanos , Células Madre Mesenquimatosas/metabolismo , Osteogénesis/genéticaRESUMEN
The treatment of leukemias, especially acute myeloid leukemia (AML), is still a challenge as can be seen by poor 5-year survival of AML. Therefore, new therapeutic approaches are needed to increase the treatment success. Epigenetic aberrations play a role in pathogenesis and resistance of leukemia. Histone deacetylase (HDAC) inhibitors (HDACIs) can normalize epigenetic disbalance by affecting gene expression. In order to decrease side effects of so far mainly used pan-HDACIs, this paper introduces the novel highly selective class IIa HDACI YAK540. A synergistic cytotoxic effect was observed between YAK540 and the proteasome inhibitor bortezomib (BTZ) as analyzed by the Chou-Talalay method. The combination of YAK540 and BTZ showed generally increased proapoptotic gene expression, increased p21 expression, and synergistic, caspase 3/7-mediated apoptosis. Notably, the cytotoxicity of YAK540 is much lower than that of pan-HDACIs. Further, combinations of YAK540 and BTZ are clearly less toxic in non-cancer HEK293 compared to HL-60 leukemia cells. Thus, the synergistic combination of class IIa selective HDACIs such as YAK540 and proteasome inhibitors represents a promising approach against leukemias to increase the anticancer effect and to reduce the general toxicity of HDACIs.
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Inhibidores de Histona Desacetilasas , Leucemia Mieloide Aguda , Humanos , Inhibidores de Histona Desacetilasas/farmacología , Inhibidores de Histona Desacetilasas/uso terapéutico , Bortezomib/farmacología , Bortezomib/uso terapéutico , Células HEK293 , Inhibidores de Proteasoma/farmacología , Apoptosis , Leucemia Mieloide Aguda/genética , Línea Celular Tumoral , Sinergismo FarmacológicoRESUMEN
Protein arginine methyltransferase-5 (PRMT5) is overexpressed in aggressive B-cell non-Hodgkin's lymphomas, including mantle cell lymphoma and diffuse large B-cell lymphoma, and supports constitutive expression of CYCLIN D1 and c-MYC. Here, we combined ChIP analysis with next-generation sequencing to identify microRNA (miRNA) genes that are targeted by PRMT5 in aggressive lymphoma cell lines. We identified enrichment of histone 3 dimethylation at Arg-8 (H3(Me2)R8) in the promoter regions of miR33b, miR96, and miR503. PRMT5 knockdown de-repressed transcription of all three miRNAs, accompanied by loss of recruitment of epigenetic repressor complexes containing PRMT5 and either histone deacetylase 2 (HDAC2) or HDAC3, enhanced binding of co-activator complexes containing p300 or CREB-binding protein (CBP), and increased acetylation of specific histones, including H2BK12, H3K9, H3K14, and H4K8 at the miRNA promoters. Re-expression of individual miRNAs in B-cell lymphoma cells down-regulated expression of PRMT5, CYCLIN D1, and c-MYC, which are all predicted targets of these miRNAs, and reduced lymphoma cell survival. Luciferase reporter assays with WT and mutant 3'UTRs of CYCLIN D1 and c-MYC mRNAs revealed that binding sites for miR33b, miR96, and miR503 are critical for translational regulation of the transcripts of these two genes. Our findings link altered PRMT5 expression to transcriptional silencing of tumor-suppressing miRNAs in lymphoma cells and reinforce PRMT5's relevance for promoting lymphoma cell growth and survival.
Asunto(s)
Ciclina D1/genética , Linfoma de Células B/enzimología , MicroARNs/metabolismo , Proteína-Arginina N-Metiltransferasas/metabolismo , Proteínas Proto-Oncogénicas c-myc/genética , Regiones no Traducidas 3' , Acetilación , Proteína de Unión a CREB/metabolismo , Secuenciación de Inmunoprecipitación de Cromatina , Ciclina D1/metabolismo , Regulación hacia Abajo , Proteína p300 Asociada a E1A/metabolismo , Silenciador del Gen , Genes Supresores de Tumor , Histona Desacetilasas/genética , Histona Desacetilasas/metabolismo , Histonas/metabolismo , Humanos , Linfoma de Células B/genética , Linfoma de Células B/metabolismo , Metilación , MicroARNs/genética , Regiones Promotoras Genéticas , Proteína-Arginina N-Metiltransferasas/genética , Proteínas Proto-Oncogénicas c-myc/metabolismoRESUMEN
The histone deacetylase sirtuin 6 (SIRT6) regulates numerous biological functions, including transcriptional repression, DNA repair, and telomere maintenance. Recombinant SIRT6 displays catalytic efficiencies 2 orders of magnitude greater for long-chain deacylation than deacetylation against peptide substrates; however, deacetylation can be enhanced by allosteric small-molecule activators. Here, we investigated the mechanisms of activated lysine deacetylation and enhanced long-chain acyl-group removal by SIRT6. Activity-based screening identified compounds that activated histone peptide deacetylation 18-48-fold. Chemical optimization based on structure-activity relationships yielded an activator with improved potency and selectivity for SIRT6. Using this novel activator, we conducted biochemical and kinetic analyses revealing that SIRT6 is activated via acceleration of a catalytic step occurring after substrate binding but before NAD+ cleavage. We identified a SIRT6 variant, R65A, that maintains basal deacetylase activity but cannot be activated and failed to enhance long-chain deacylation. Additional biochemical studies revealed that Arg-65 is critical for activation by facilitating a conformational step that initiates chemical catalysis. This work suggests that SIRT6 activation of deacetylation involves a similar mechanism to improved catalysis as that of long-chain deacylation. The identification of novel SIRT6 activators and the molecular insights into activation and catalysis presented here provide a foundational understanding for physiological SIRT6 activation and for rational design of activating molecules.
Asunto(s)
Histonas/metabolismo , Sirtuinas/química , Regulación Alostérica/efectos de los fármacos , Biocatálisis/efectos de los fármacos , Ácidos Grasos/química , Células HEK293 , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Cinética , Lípidos/química , Mutagénesis , Mutación , NAD/metabolismo , Péptidos/química , Péptidos/metabolismo , Unión Proteica/efectos de los fármacos , Unión Proteica/genética , Conformación Proteica/efectos de los fármacos , Sirtuinas/genética , Sirtuinas/metabolismo , Bibliotecas de Moléculas Pequeñas/químicaRESUMEN
Sirtuin 6 (SIRT6) is a nuclear NAD+-dependent deacetylase of histone H3 that regulates genome stability and gene expression. However, nonhistone substrates and additional catalytic activities of SIRT6, including long-chain deacylation and mono-ADP-ribosylation of other proteins, have also been reported, but many of these noncanonical roles remain enigmatic. Genetic studies have revealed critical homeostatic cellular functions of SIRT6, underscoring the need to better understand which catalytic functions and molecular pathways are driving SIRT6-associated phenotypes. At the physiological level, SIRT6 activity promotes increased longevity by regulating metabolism and DNA repair. Recent work has identified natural products and synthetic small molecules capable of activating the inefficient in vitro deacetylase activity of SIRT6. Here, we discuss the cellular functions of SIRT6 with a focus on attributing its catalytic activity to its proposed biological functions. We cover the molecular architecture and catalytic mechanisms that distinguish SIRT6 from other NAD+-dependent deacylases. We propose that combining specific SIRT6 amino acid substitutions identified in enzymology studies and activity-selective compounds could help delineate SIRT6 functions in specific biological contexts and resolve the apparently conflicting roles of SIRT6 in processes such as tumor development. We further highlight the recent development of small-molecule modulators that provide additional biological insight into SIRT6 functions and offer therapeutic approaches to manage metabolic and age-associated diseases.