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Aging Cell Aug 2023Several molecular mechanisms have been described in Alzheimer's disease (AD), including repressed gene transcription and mitochondrial and endoplasmic reticulum (ER)...
Several molecular mechanisms have been described in Alzheimer's disease (AD), including repressed gene transcription and mitochondrial and endoplasmic reticulum (ER) dysfunction. In this study, we evaluate the potential efficacy of transcriptional modifications exerted by inhibition or knockdown of class I histone deacetylases (HDACs) in ameliorating ER-mitochondria cross-talk in AD models. Data show increased HDAC3 protein levels and decreased acetyl-H3 in AD human cortex, and increased HDAC2-3 in MCI peripheral human cells, HT22 mouse hippocampal cells exposed to Aβ oligomers (AβO) and APP/PS1 mouse hippocampus. Tacedinaline (Tac, a selective class I HDAC inhibitor) counteracted the increase in ER-Ca retention and mitochondrial Ca accumulation, mitochondrial depolarization and impaired ER-mitochondria cross-talk, as observed in 3xTg-AD mouse hippocampal neurons and AβO-exposed HT22 cells. We further demonstrated diminished mRNA levels of proteins involved in mitochondrial-associated ER membranes (MAM) in cells exposed to AβO upon Tac treatment, along with reduction in ER-mitochondria contacts (MERCS) length. HDAC2 silencing reduced ER-mitochondria Ca transfer and mitochondrial Ca retention, while knockdown of HDAC3 decreased ER-Ca accumulation in AβO-treated cells. APP/PS1 mice treated with Tac (30 mg/kg/day) also showed regulation of mRNA levels of MAM-related proteins, and reduced Aβ levels. These data demonstrate that Tac normalizes Ca signaling between mitochondria and ER, involving the tethering between the two organelles in AD hippocampal neural cells. Tac-mediated AD amelioration occurs through the regulation of protein expression at MAM, as observed in AD cells and animal models. Data support transcriptional regulation of ER-mitochondria communication as a promising target for innovative therapeutics in AD.
Topics: Mice; Humans; Animals; Alzheimer Disease; Amyloid beta-Peptides; Histone Deacetylases; Mitochondria; Endoplasmic Reticulum
PubMed: 37358017
DOI: 10.1111/acel.13895 -
Journal For Immunotherapy of Cancer Jan 2023While major advances have been made in improving the quality of life and survival of children with most forms of medulloblastoma (MB), those with MYC-driven tumors...
Tacedinaline (CI-994), a class I HDAC inhibitor, targets intrinsic tumor growth and leptomeningeal dissemination in MYC-driven medulloblastoma while making them susceptible to anti-CD47-induced macrophage phagocytosis via NF-kB-TGM2 driven tumor inflammation.
BACKGROUND
While major advances have been made in improving the quality of life and survival of children with most forms of medulloblastoma (MB), those with MYC-driven tumors (Grp3-MB) still suffer significant morbidity and mortality. There is an urgent need to explore multimodal therapeutic regimens which are effective and safe for children. Large-scale studies have revealed abnormal cancer epigenomes caused by mutations and structural alterations of chromatin modifiers, aberrant DNA methylation, and histone modification signatures. Therefore, targeting epigenetic modifiers for cancer treatment has gained increasing interest, and inhibitors for various epigenetic modulators have been intensively studied in clinical trials. Here, we report a cross-entity, epigenetic drug screen to evaluate therapeutic vulnerabilities in MYC amplified MB, which sensitizes them to macrophage-mediated phagocytosis by targeting the CD47-signal regulatory protein α (SIRPα) innate checkpoint pathway.
METHODS
We performed a primary screen including 78 epigenetic inhibitors and a secondary screen including 20 histone deacetylase inhibitors (HDACi) to compare response profiles in atypical teratoid/rhabdoid tumor (AT/RT, n=11), MB (n=14), and glioblastoma (n=14). This unbiased approach revealed the preferential activity of HDACi in MYC-driven MB. Importantly, the class I selective HDACi, CI-994, showed significant cell viability reduction mediated by induction of apoptosis in MYC-driven MB, with little-to-no activity in non-MYC-driven MB, AT/RT, and glioblastoma in vitro. We tested the combinatorial effect of targeting class I HDACs and the CD47-SIRPa phagocytosis checkpoint pathway using in vitro phagocytosis assays and in vivo orthotopic xenograft models.
RESULTS
CI-994 displayed antitumoral effects at the primary site and the metastatic compartment in two orthotopic mouse models of MYC-driven MB. Furthermore, RNA sequencing revealed nuclear factor-kB (NF-κB) pathway induction as a response to CI-994 treatment, followed by transglutaminase 2 (TGM2) expression, which enhanced inflammatory cytokine secretion. We further show interferon-γ release and cell surface expression of engulfment ('eat-me') signals (such as calreticulin). Finally, combining CI-994 treatment with an anti-CD47 mAb targeting the CD47-SIRPα phagocytosis checkpoint enhanced in vitro phagocytosis and survival in tumor-bearing mice.
CONCLUSION
Together, these findings suggest a dynamic relationship between MYC amplification and innate immune suppression in MYC amplified MB and support further investigation of phagocytosis modulation as a strategy to enhance cancer immunotherapy responses.
Topics: Humans; Mice; Animals; Medulloblastoma; NF-kappa B; Histone Deacetylase Inhibitors; Glioblastoma; Protein Glutamine gamma Glutamyltransferase 2; Quality of Life; Phagocytosis; Macrophages; Inflammation; Cerebellar Neoplasms
PubMed: 36639156
DOI: 10.1136/jitc-2022-005871 -
Cell Proliferation Jun 2018Histone deacetylases (HDACs) are commonly dysregulated in cancer and represent promising therapeutic targets. However, global HDAC inhibitors have shown limited efficacy...
OBJECTIVES
Histone deacetylases (HDACs) are commonly dysregulated in cancer and represent promising therapeutic targets. However, global HDAC inhibitors have shown limited efficacy in the treatment of solid tumours, including hepatocellular carcinoma (HCC). In this study, we investigated the therapeutic effect of selectively inhibiting HDAC1 and 2 in HCC.
METHODS
HDAC1 inhibitor Tacedinaline (CI994), HDAC2 inhibitor Santacruzamate A (CAY10683), HDAC1/2 common inhibitor Romidepsin (FK228) and global HDAC inhibitor Vorinostat (SAHA) were used to treat HCC cells. Cell cycle, apoptosis and the protein levels of CDKs and CDKNs were performed to evaluate HCC cell growth. Inhibition of HDAC1/2 by RNAi was further investigated.
RESULTS
Combined inhibition of HDAC1/2 led to HCC cell morphology changes, growth inhibition, cell cycle blockage and apoptosis in vitro and suppressed the growth of subcutaneous HCC xenograft tumours in vivo. p21 and p19 , which play roles in cell cycle blockage and apoptosis induction, were upregulated. Inhibition of HDAC1/2 by siRNA further demonstrated that HDAC1 and 2 cooperate in blocking the cell cycle and inducing apoptosis via p19 and p21 upregulation. Finally, H3K18, H3K56 and H4K12 in the p19 and p21 promoter regions were found to be targets of HDAC1/2.
CONCLUSIONS
Pharmacological or transcriptional inhibition of HDAC1/2 increases p19 and p21 expression, decreases CDK expression and arrests HCC growth. These results indicated a potential pharmacological mechanism of selective HDAC1/2 inhibitors in HCC therapy.
Topics: Animals; Antineoplastic Agents; Apoptosis; Carcinoma, Hepatocellular; Cell Cycle Checkpoints; Cyclin-Dependent Kinase Inhibitor p19; Cyclin-Dependent Kinase Inhibitor p21; Depsipeptides; Gene Expression Regulation, Neoplastic; Hep G2 Cells; Histone Deacetylase 1; Histone Deacetylase 2; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; Liver Neoplasms; Mice, Nude; Transcription, Genetic; Up-Regulation; Vorinostat; Xenograft Model Antitumor Assays
PubMed: 29484736
DOI: 10.1111/cpr.12447 -
Life Sciences Dec 2023The aim of our study was to determine the effect of histone deacetylase (HDAC) inhibitors (HDACis) on somatostatin type-2 receptor (SSTR2) expression and...
AIMS
The aim of our study was to determine the effect of histone deacetylase (HDAC) inhibitors (HDACis) on somatostatin type-2 receptor (SSTR2) expression and [In]In-/[Lu]Lu-DOTA-TATE uptake in vitro and in vivo.
MATERIALS AND METHODS
The human cell lines NCI-H69 (small-cell lung carcinoma) and BON-1 (pancreatic neuroendocrine tumor) were treated with HDACis (i.e. entinostat, mocetinostat (MOC), LMK-235, CI-994 or panobinostat (PAN)), and SSTR2 mRNA expression levels and [In]In-DOTA-TATE uptake were measured. Furthermore, vehicle- and HDACi-treated NCI-H69 and BON-1 tumor-bearing mice were injected with radiolabeled DOTA-TATE followed by biodistribution studies. Additionally, SSTR2 and HDAC mRNA expression of xenografts, and of NCI-H69, BON-1, NCI-H727 (human pulmonary carcinoid) and GOT1 (human midgut neuroendocrine tumor) cells were determined.
KEY FINDINGS
HDACi treatment resulted in the desired effects in vitro. However, no significant increase in tumoral DOTA-TATE uptake was observed after HDACi treatment in NCI-H69 tumor-bearing animals, whereas tumoral SSTR2 mRNA and/or protein expression levels were significantly upregulated after treatment with MOC, CI-994 and PAN, i.e. a maximum of 2.1- and 1.3-fold, respectively. Analysis of PAN-treated BON-1 xenografts solely demonstrated increased SSTR2 mRNA expression levels. Comparison of HDACs and SSTR2 expression in BON-1 and NCI-H69 xenografts showed a significantly higher expression of 6/11 HDACs in BON-1 xenografts. Of these HDACs, a significant inverse correlation was found between HDAC3 and SSTR2 expression (Pearson r = -0.92) in the studied cell lines.
SIGNIFICANCE
To conclude, tumoral uptake levels of radiolabeled DOTA-TATE were not enhanced after HDACi treatment in vivo, but, depending on the applied inhibitor, increased SSTR2 expression levels were observed.
Topics: Humans; Mice; Animals; Receptors, Somatostatin; Tissue Distribution; Somatostatin; Cell Line, Tumor; RNA, Messenger
PubMed: 37907154
DOI: 10.1016/j.lfs.2023.122173 -
ChemMedChem May 2022Herein we report the structure-activity and structure-physicochemical property relationships of a series of class I selective ortho-aminoanilides targeting the...
Herein we report the structure-activity and structure-physicochemical property relationships of a series of class I selective ortho-aminoanilides targeting the "foot-pocket" in HDAC1&2. To balance the structural benefits and the physicochemical disadvantages of these substances, we started with a set of HDACi related to tacedinaline (CI-994) and evaluated their solubility, lipophilicity (log D ) and inhibition of selected HDAC isoforms. Subsequently, we selected the most promising "capless" HDACi and transferred its ZBG to our previously published scaffold featuring a peptoid-based cap group. The resulting hit compound 10 c (LSH-A54) showed favorable physicochemical properties and is a potent, selective HDAC1/2 inhibitor. The following evaluation of its slow binding properties revealed that LSH-A54 binds tightly to HDAC1 in an induced-fit mechanism. The potent HDAC1/2 inhibitory properties were reflected by attenuated cell migration in a modified wound healing assay and reduced cell viability in a clonogenic survival assay in selected breast cancer cell lines.
Topics: Histone Deacetylase 1; Histone Deacetylase Inhibitors; Histone Deacetylases; Peptoids
PubMed: 35073610
DOI: 10.1002/cmdc.202100755 -
Frontiers in Neuroscience 2021Elderly patients treated with antipsychotic drugs often experience increased severity and frequency of side effects, yet the mechanisms are not well understood. Studies...
Elderly patients treated with antipsychotic drugs often experience increased severity and frequency of side effects, yet the mechanisms are not well understood. Studies from our group indicate age-related histone modifications at drug targeted receptor gene promoters may contribute to the increased side effects, and histone deacetylase (HDAC) inhibitors entinostat (MS-275) and valproic acid (VPA) could reverse typical antipsychotic haloperidol (HAL) induced motor-side effects. However, whether such effects could be dose dependent and whether HDAC inhibitors could improve memory function in aged mice is unknown. We co-treated selective class 1 HDAC inhibitor tacedinaline (CI-994) at different doses (10, 20, and 30 mg/kg) with HAL (0.05 mg/kg) in young (3 months) and aged (21 months) mice for 14 consecutive days, then motor and memory behavioral tests were conducted, followed by biochemical measurements. CI-994 at doses of 10 and 20 mg/kg could decrease HAL-induced cataleptic episodes but only 20 mg/kg was sufficient to improve motor coordination in aged mice. Additionally, CI-994 at 10 and 20 mg/kg mitigate HAL-induced memory impairment in aged mice. Biochemical analyses showed increased acetylation of histone marks H3K27ac and H3K18ac at the dopamine 2 receptor (D2R) gene () promoter and increased expression of the mRNA and D2R protein in the striatum of aged mice after administration of CI-994 at 20 mg/kg. Our results suggest CI-994 can reduce HAL-induced motor and memory side effects in aged mice. These effects may act through an increase of acetylation at the promoter, thereby restoring D2R expression and improving antipsychotic drug action.
PubMed: 34690667
DOI: 10.3389/fnins.2021.674745 -
Journal of Nuclear Medicine : Official... Nov 2016Targeted diagnosis and therapy enable precise tumor detection and treatment. Successful examples for precise tumor targeting are diagnostic and therapeutic radioligands....
UNLABELLED
Targeted diagnosis and therapy enable precise tumor detection and treatment. Successful examples for precise tumor targeting are diagnostic and therapeutic radioligands. However, patients with tumors expressing low levels of the relevant molecular targets are deemed ineligible for such targeted approaches.
METHODS
We performed a screen for drugs that upregulate the somatostatin receptor subtype 2 (sstr). Then, we characterized the effects of these drugs on transcriptional, translational, and functional levels in vitro and in vivo.
RESULTS
We identified 9 drugs that act as epigenetic modifiers, including the inhibitor of DNA methyltransferase decitabine as well as the inhibitors of histone deacetylase tacedinaline and romidepsin. In vitro, these drugs upregulated sstr on transcriptional, translational, and functional levels in a time- and dose-dependent manner. Thereby, their combinations revealed synergistic effects. In vivo, drug-based sstr upregulation improved the tumor-to-background and tumor-to-kidney ratios, which are the key determinants of successful sstr-targeted imaging and radiopeptide therapy.
CONCLUSION
We present an approach that uses epigenetic modifiers to improve sstr targeting in vitro and in vivo. Translation of this method into the clinic may potentially convert patients ineligible for targeted imaging and therapy to eligible candidates.
Topics: Animals; Azacitidine; Biomarkers, Tumor; Cell Line, Tumor; Decitabine; Drug Evaluation, Preclinical; Gene Expression Regulation, Neoplastic; Mice; Mice, Nude; Molecular Targeted Therapy; Neoplasms, Experimental; Organometallic Compounds; Pathology, Molecular; Positron-Emission Tomography; Receptors, Somatostatin; Reproducibility of Results; Sensitivity and Specificity; Up-Regulation
PubMed: 27363833
DOI: 10.2967/jnumed.115.165092 -
Frontiers in Immunology 2023To address a novel lower-dose rituximab (RTX) therapy strategy based on our clinical experience and assess its efficacy and safety in neuromyelitis optica spectrum...
OBJECTIVE
To address a novel lower-dose rituximab (RTX) therapy strategy based on our clinical experience and assess its efficacy and safety in neuromyelitis optica spectrum disorder (NMOSD).
METHODS
A multicenter, open-label, self-controlled, prospective follow-up study. Totally, 108 NMOSD patients were enrolled and a lower-dose RTX strategy was applied including 100 mg weekly for 3 weeks and then reinfusions every 6 months. Annualized relapse rate (ARR), the expanded disability status scale (EDSS) score and length of spinal cord lesions were included to evaluate the efficacy. Side effects were recorded to assess the safety profile.
RESULTS
Of 108 patients, 80 (74.1%) initiated low-dose RTX therapy immediately after acute attack treatment and 33 (30.6%) initiated it after the first attack. During a median treatment period of 35.5 (22.0-48.8) months, significant decreases were observed in median ARR (1.1 [0.8-2.0] versus 0 [0-0.2], < 0.001), EDSS score (3.5 [2.5-4.0] versus 2.0 [1.0-3.0], < 0.001) and spinal cord lesion segments (5.0 [4.0-8.0] versus 3.0 [1.0-6.0], < 0.001). The cumulative risk of relapses significantly decreased during the post- versus pre-RTX period (HR 0.238, 95%CI 0.160-0.356, < 0.001) and on early therapy initiated within 24 months after disease onset versus delayed therapy (HR 0.506, 95%CI 0.258-0.994, = 0.041). No serious side effects were recorded and all the subjects did not discontinue treatment due to RTX-related side effects.
CONCLUSION
Our research provided evidence supporting the lower-dose RTX strategy in treating NMOSD and reopened the issues of optimal dosage and therapy initiation timing.
Topics: Humans; Neuromyelitis Optica; Follow-Up Studies; Rituximab; Prospective Studies; Secondary Prevention; Drug-Related Side Effects and Adverse Reactions
PubMed: 37614240
DOI: 10.3389/fimmu.2023.1148632 -
Journal of Nuclear Medicine : Official... Sep 2019Peptide receptor radionuclide therapy in advanced neuroendocrine tumors (NETs) demonstrates a limited objective response rate. The therapeutic efficacy might be further...
Combination of 5-Fluorouracil with Epigenetic Modifiers Induces Radiosensitization, Somatostatin Receptor 2 Expression, and Radioligand Binding in Neuroendocrine Tumor Cells In Vitro.
Peptide receptor radionuclide therapy in advanced neuroendocrine tumors (NETs) demonstrates a limited objective response rate. The therapeutic efficacy might be further increased by peptide receptor chemoradionuclide therapy. In this preclinical study, we explored the effects of 5-fluorouracil plus the DNA methyltransferase inhibitor decitabine or the histone deacetylase inhibitor tacedinaline on NET cells in vitro. Human NET cell lines BON1 and QGP1 were treated with 5-fluorouracil alone or in combination with decitabine or tacedinaline, respectively. Radiosensitivity was tested in combination with γ-irradiation at doses of 0, 2, 4, or 6 Gy by colony formation assay. Somatostatin receptor type 2 (SSTR2) expression and Ga-DOTATOC uptake by human NET cell lines were investigated by Western blot analysis and by a radioligand binding assay. Treatment with 5-fluorouracil alone or in combination with decitabine or tacedinaline reduced tumor cell viability and induced apoptosis, enhanced radiosensitivity in BON1 and QGP1 cells, induced SSTR2 expression, and resulted in increased radioligand binding of Ga-DOTATOC in NET cells. This preclinical study demonstrated that 5-fluorouracil alone or in combination with decitabine or tacedinaline caused radiosensitization of tumor cells, upregulation of SSTR2 expression in tumor cells, and increased radioligand binding of Ga-DOTATOC to these tumor cells. These preclinical in vitro findings indicate that 5-fluorouracil in combination with epigenetic modifiers might be a putative strategy to improve the treatment efficacy of peptide receptor chemoradionuclide therapy in NET.
Topics: Apoptosis; Benzamides; Cell Line, Tumor; Cell Survival; Decitabine; Dose-Response Relationship, Radiation; Epigenesis, Genetic; Flow Cytometry; Fluorouracil; Histones; Humans; Microscopy, Fluorescence; Neuroendocrine Tumors; Octreotide; Organometallic Compounds; Phenylenediamines; Radiation-Sensitizing Agents; Receptors, Somatostatin; Tumor Suppressor p53-Binding Protein 1
PubMed: 30796167
DOI: 10.2967/jnumed.118.224048 -
AIDS Research and Human Retroviruses Feb 2016Cessation of highly active antiretroviral therapy (HAART) in HIV-infected individual leads to a rebound of viral replication due to reactivation of a viral reservoir...
Short Communication: The Broad-Spectrum Histone Deacetylase Inhibitors Vorinostat and Panobinostat Activate Latent HIV in CD4(+) T Cells In Part Through Phosphorylation of the T-Loop of the CDK9 Subunit of P-TEFb.
Cessation of highly active antiretroviral therapy (HAART) in HIV-infected individual leads to a rebound of viral replication due to reactivation of a viral reservoir composed largely of latently infected memory CD4(+) T cells. Efforts to deplete this reservoir have focused on reactivation of transcriptionally silent latent proviruses. HIV provirus transcription depends critically on the positive transcription elongation factor b (P-TEFb), whose core components are cyclin-dependent kinase 9 (CDK9) and cyclin T1. In resting CD4(+) cells, the functional levels of P-TEFb are extremely low. Cellular activation upregulates cyclin T1 protein levels and CDK9 T-loop (T186) phosphorylation. The broad-spectrum histone deacetylase inhibitors (HDACis) vorinostat and panobinostat have been shown to reactivate latent virus in vivo in HAART-treated individuals. In this study, we have found that vorinostat and panobinostat activate P-TEFb in resting primary CD4(+) T cells through induction of CDK9 T-loop phosphorylation. In contrast, tacedinaline and romidepsin, HDAC 1 and 2 inhibitors, were unable to activate CDK9 T-loop phosphorylation. We used a CCL19 primary CD4(+) T-cell model HIV latency to assess the correlation between induction of CDK9 T-loop phosphorylation and reactivation of latent HIV virus by HDACis. Vorinostat and panobinostat treatment of cells harboring latent HIV increased CDK9 T-loop phosphorylation and reactivation of latent virus, whereas tacedinaline and romidepsin failed to induce T-loop phosphorylation or reactivate latent virus. We conclude that the ability of vorinostat and panobinostat to induce latent HIV is, in part, likely due to the ability of the broad-spectrum HDACis to upregulate P-TEFb through increased CDK9 T-loop phosphorylation.
Topics: Antiretroviral Therapy, Highly Active; Benzamides; CD4-Positive T-Lymphocytes; Cells, Cultured; Cyclin T; Cyclin-Dependent Kinase 9; Depsipeptides; Enzyme Activation; Gene Expression Regulation, Viral; HIV Infections; HIV-1; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; Indoles; Panobinostat; Phenylenediamines; Phosphorylation; Positive Transcriptional Elongation Factor B; Proviruses; Virus Activation; Virus Latency; Virus Replication; Vorinostat
PubMed: 26727990
DOI: 10.1089/AID.2015.0347