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1.
Proc Natl Acad Sci U S A ; 120(25): e2300987120, 2023 06 20.
Article in English | MEDLINE | ID: mdl-37307442

ABSTRACT

T cell antigen receptor stimulation induces tyrosine phosphorylation of downstream signaling molecules and the phosphatidylinositol, Ras, MAPK, and PI3 kinase pathways, leading to T cell activation. Previously, we reported that the G-protein-coupled human muscarinic receptor could bypass tyrosine kinases to activate the phosphatidylinositol pathway and induce interleukin-2 production in Jurkat leukemic T cells. Here, we demonstrate that stimulating G-protein-coupled muscarinic receptors (M1 and synthetic hM3Dq) can activate primary mouse T cells if PLCß1 is coexpressed. Resting peripheral hM3Dq+PLCß1 (hM3Dq/ß1) T cells did not respond to clozapine, an hM3Dq agonist, unless they were preactivated by TCR and CD28 stimulation which increased hM3Dq and PLCß1 expression. This permitted large calcium and phosphorylated ERK responses to clozapine. Clozapine treatment induced high IFN-γ, CD69, and CD25 expression, but surprisingly did not induce substantial IL-2 in hM3Dq/ß1 T cells. Importantly, costimulation of both muscarinic receptors plus the TCR even led to reduced IL-2 expression, suggesting a selective inhibitory effect of muscarinic receptor costimulation. Stimulation of muscarinic receptors induced strong nuclear translocation of NFAT and NFκB and activated AP-1. However, stimulation of hM3Dq led to reduced IL-2 mRNA stability which correlated with an effect on the IL-2 3'UTR activity. Interestingly, stimulation of hM3Dq resulted in reduced pAKT and its downstream pathway. This may explain the inhibitory impact on IL-2 production in hM3Dq/ß1T cells. Moreover, an inhibitor of PI3K reduced IL-2 production in TCR-stimulated hM3Dq/ß1 CD4 T cells, suggesting that activating the pAKT pathway is critical for IL-2 production in T cells.


Subject(s)
Clozapine , Interleukin-2 , Humans , Animals , Mice , Receptors, Muscarinic , Interferon-gamma , GTP-Binding Proteins , Tyrosine
2.
Nat Commun ; 14(1): 1187, 2023 03 02.
Article in English | MEDLINE | ID: mdl-36864031

ABSTRACT

Ferroptosis is mediated by lipid peroxidation of phospholipids containing polyunsaturated fatty acyl moieties. Glutathione, the key cellular antioxidant capable of inhibiting lipid peroxidation via the activity of the enzyme glutathione peroxidase 4 (GPX-4), is generated directly from the sulfur-containing amino acid cysteine, and indirectly from methionine via the transsulfuration pathway. Herein we show that cysteine and methionine deprivation (CMD) can synergize with the GPX4 inhibitor RSL3 to increase ferroptotic cell death and lipid peroxidation in both murine and human glioma cell lines and in ex vivo organotypic slice cultures. We also show that a cysteine-depleted, methionine-restricted diet can improve therapeutic response to RSL3 and prolong survival in a syngeneic orthotopic murine glioma model. Finally, this CMD diet leads to profound in vivo metabolomic, proteomic and lipidomic alterations, highlighting the potential for improving the efficacy of ferroptotic therapies in glioma treatment with a non-invasive dietary modification.


Subject(s)
Ferroptosis , Glioma , Humans , Animals , Mice , Methionine , Cysteine , Proteomics , Racemethionine , Glioma/drug therapy
3.
bioRxiv ; 2023 Feb 23.
Article in English | MEDLINE | ID: mdl-36865302

ABSTRACT

Glioma cells hijack developmental transcriptional programs to control cell state. During neural development, lineage trajectories rely on specialized metabolic pathways. However, the link between tumor cell state and metabolic programs is poorly understood in glioma. Here we uncover a glioma cell state-specific metabolic liability that can be leveraged therapeutically. To model cell state diversity, we generated genetically engineered murine gliomas, induced by deletion of p53 alone (p53) or with constitutively active Notch signaling (N1IC), a pathway critical in controlling cellular fate. N1IC tumors harbored quiescent astrocyte-like transformed cell states while p53 tumors were predominantly comprised of proliferating progenitor-like cell states. N1IC cells exhibit distinct metabolic alterations, with mitochondrial uncoupling and increased ROS production rendering them more sensitive to inhibition of the lipid hydroperoxidase GPX4 and induction of ferroptosis. Importantly, treating patient-derived organotypic slices with a GPX4 inhibitor induced selective depletion of quiescent astrocyte-like glioma cell populations with similar metabolic profiles.

4.
Cells ; 11(19)2022 09 22.
Article in English | MEDLINE | ID: mdl-36230918

ABSTRACT

Glioblastoma WHO IV (GBM), the most common primary brain tumor in adults, is a heterogenous malignancy that displays a reprogrammed metabolism with various fuel sources at its disposal. Tumor cells primarily appear to consume glucose to entertain their anabolic and catabolic metabolism. While less effective for energy production, aerobic glycolysis (Warburg effect) is an effective means to drive biosynthesis of critical molecules required for relentless growth and resistance to cell death. Targeting the Warburg effect may be an effective venue for cancer treatment. However, past and recent evidence highlight that this approach may be limited in scope because GBM cells possess metabolic plasticity that allows them to harness other substrates, which include but are not limited to, fatty acids, amino acids, lactate, and acetate. Here, we review recent key findings in the literature that highlight that GBM cells substantially reprogram their metabolism upon therapy. These studies suggest that blocking glycolysis will yield a concomitant reactivation of oxidative energy pathways and most dominantly beta-oxidation of fatty acids.


Subject(s)
Glioblastoma , Amino Acids/metabolism , Fatty Acids/therapeutic use , Glioblastoma/metabolism , Glucose , Humans , Lactic Acid/metabolism , Oxidative Phosphorylation
5.
Cell Rep ; 41(3): 111488, 2022 10 18.
Article in English | MEDLINE | ID: mdl-36260999

ABSTRACT

Cells possess several conserved adaptive mechanisms to respond to stress. Stress signaling is initiated to reestablish cellular homeostasis, but its effects on the tissue or systemic levels are far less understood. We report that the secreted luminal domain of the endoplasmic reticulum (ER) stress transducer CREB3L2 (which we name TAILS [transmissible activator of increased cell livability under stress]) is an endogenous, cell non-autonomous activator of neuronal resilience. In response to oxidative insults, neurons secrete TAILS, which potentiates hedgehog signaling through direct interaction with Sonic hedgehog (SHH) and its receptor PTCH1, leading to improved antioxidant signaling and mitochondrial function in neighboring neurons. In an in vivo model of ischemic brain injury, administration of TAILS enables survival of CNS neurons and fully preserves cognitive function in behavioral tests. Our findings reveal an SHH-mediated, cell non-autonomous branch of cellular stress signaling that confers resilience to oxidative stress in the mature brain, providing protection from ischemic neurodegeneration.


Subject(s)
Antioxidants , Hedgehog Proteins , Hedgehog Proteins/metabolism , Neurons/metabolism , Oxidative Stress/physiology , Signal Transduction/physiology
6.
Cell ; 185(14): 2591-2608.e30, 2022 07 07.
Article in English | MEDLINE | ID: mdl-35803246

ABSTRACT

Melanoma brain metastasis (MBM) frequently occurs in patients with advanced melanoma; yet, our understanding of the underlying salient biology is rudimentary. Here, we performed single-cell/nucleus RNA-seq in 22 treatment-naive MBMs and 10 extracranial melanoma metastases (ECMs) and matched spatial single-cell transcriptomics and T cell receptor (TCR)-seq. Cancer cells from MBM were more chromosomally unstable, adopted a neuronal-like cell state, and enriched for spatially variably expressed metabolic pathways. Key observations were validated in independent patient cohorts, patient-derived MBM/ECM xenograft models, RNA/ATAC-seq, proteomics, and multiplexed imaging. Integrated spatial analyses revealed distinct geography of putative cancer immune evasion and evidence for more abundant intra-tumoral B to plasma cell differentiation in lymphoid aggregates in MBM. MBM harbored larger fractions of monocyte-derived macrophages and dysfunctional TOX+CD8+ T cells with distinct expression of immune checkpoints. This work provides comprehensive insights into MBM biology and serves as a foundational resource for further discovery and therapeutic exploration.


Subject(s)
Brain Neoplasms , Melanoma , Brain Neoplasms/drug therapy , Brain Neoplasms/secondary , CD8-Positive T-Lymphocytes/pathology , Ecosystem , Humans , RNA-Seq
7.
Clin Cancer Res ; 28(9): 1881-1895, 2022 05 02.
Article in English | MEDLINE | ID: mdl-35417530

ABSTRACT

PURPOSE: Novel therapeutic targets are critical to unravel for the most common primary brain tumor in adults, glioblastoma (GBM). We have identified a novel synthetic lethal interaction between ClpP activation and HDAC1/2 inhibition that converges on GBM energy metabolism. EXPERIMENTAL DESIGN: Transcriptome, metabolite, and U-13C-glucose tracing analyses were utilized in patient-derived xenograft (PDX) models of GBM. Orthotopic GBM models were used for in vivo studies. RESULTS: We showed that activation of the mitochondrial ClpP protease by mutant ClpP (Y118A) or through utilization of second-generation imipridone compounds (ONC206 and ONC212) in combination with genetic interference of HDAC1 and HDAC2 as well as with global (panobinostat) or selective (romidepsin) HDAC inhibitors caused synergistic reduction of viability in GBM model systems, which was mediated by interference with tricarboxylic acid cycle activity and GBM cell respiration. This effect was partially mediated by activation of apoptosis along with activation of caspases regulated chiefly by Bcl-xL and Mcl-1. Knockdown of the ClpP protease or ectopic expression of a ClpP D190A mutant substantially rescued from the inhibition of oxidative energy metabolism as well as from the reduction of cellular viability by ClpP activators and the combination treatment, respectively. Finally, utilizing GBM PDX models, we demonstrated that the combination treatment of HDAC inhibitors and imipridones prolonged host survival more potently than single treatments or vehicle in vivo. CONCLUSIONS: Collectively, these observations suggest that the efficacy of HDAC inhibitors might be significantly enhanced through ClpP activators in model systems of human GBM.


Subject(s)
Glioblastoma , Humans , Apoptosis/genetics , Cell Line, Tumor , Cell Proliferation , Endopeptidase Clp/genetics , Endopeptidase Clp/metabolism , Endopeptidase Clp/therapeutic use , Glioblastoma/drug therapy , Glioblastoma/genetics , Glioblastoma/metabolism , Histone Deacetylase 1/genetics , Histone Deacetylase Inhibitors/pharmacology , Histone Deacetylase Inhibitors/therapeutic use , Peptide Hydrolases/genetics , Synthetic Lethal Mutations , Xenograft Model Antitumor Assays
8.
Methods Mol Biol ; 2445: 305-328, 2022.
Article in English | MEDLINE | ID: mdl-34973000

ABSTRACT

Glioblastoma (GBM), a highly malignant primary brain tumor, inevitably leads to death. In the last decade, a variety of novel molecular characteristics of GBMs were unraveled. The identification of the mutation in the IDH1 and less commonly IDH2 gene was surprising and ever since has nurtured research in the field of GBM metabolism. While initially thought that mutated IDH1 were to act as a loss of function mutation it became clear that it conferred the production of an oncometabolite that in turn substantially reprograms GBM metabolism. While mutated IDH1 represents truly the tip of the iceberg, there are numerous other related observations in GBM that are of significant interest to the field, including the notion that oxidative metabolism appears to play a more critical role than believed earlier. Metabolic zoning is another important hallmark of GBM since it was found that the infiltrative margin that drives GBM progression reveals enrichment of fatty acid derivatives. Consistently, fatty acid metabolism appears to be a novel therapeutic target for GBM. How metabolism in GBM intersects is another pivotal issue that appears to be important for its progression and response and resistance to therapies. In this review, we will summarize some of the most relevant findings related to GBM metabolism and cell death and how these observations are influencing the field. We will provide current approaches that are applied in the field to measure metabolomic changes in GBM models, including the detection of unlabeled and labeled metabolites as well as extracellular flux analysis.


Subject(s)
Brain Neoplasms , Glioblastoma , Brain Neoplasms/pathology , Glioblastoma/pathology , Humans , Isocitrate Dehydrogenase/genetics , Isocitrate Dehydrogenase/metabolism , Mutation
9.
Immunol Rev ; 307(1): 145-160, 2022 05.
Article in English | MEDLINE | ID: mdl-34923645

ABSTRACT

Establishing both central and peripheral tolerance requires the appropriate TCR signaling strength to discriminate self- from agonist-peptide bound to self MHC molecules. ZAP70, a cytoplasmic tyrosine kinase, directly interacts with the TCR complex and plays a central and requisite role in TCR signaling in both thymocytes and peripheral T cells. By studying ZAP70 hypomorphic mutations in mice and humans with a spectrum of hypoactive or hyperactive activities, we have gained insights into mechanisms of central and peripheral tolerance. Interestingly, both hypoactive and hyperactive ZAP70 can lead to the development of autoimmune diseases, albeit through distinct mechanisms. Immature thymocytes and mature T cells rely on normal ZAP70 function to complete their development in the thymus and to modulate T cell responses in the periphery. Hypoactive ZAP70 function compromises key developmental checkpoints required to establish central tolerance, allowing thymocytes with potentially self-reactive TCRs a greater chance to escape negative selection. Such 'forbidden clones' may escape into the periphery and may pose a greater risk for autoimmune disease development since they may not engage negative regulatory mechanisms as effectively. Hyperactive ZAP70 enhances thymic negative selection but some thymocytes will, nonetheless, escape negative selection and have greater sensitivity to weak and self-ligands. Such cells must be controlled by mechanisms involved in anergy, expansion of Tregs, and upregulation of inhibitory receptors or signaling molecules. However, such potentially autoreactive cells may still be able to escape control by peripheral negative regulatory constraints. Consistent with findings in Zap70 mutants, the signaling defects in at least one ZAP70 substrate, LAT, can also lead to autoimmune disease. By dissecting the similarities and differences among mouse models of patient disease or mutations in ZAP70 that affect TCR signaling strength, we have gained insights into how perturbed ZAP70 function can lead to autoimmunity. Because of our work and that of others on ZAP70, it is likely that perturbations in other molecules affecting TCR signaling strength will be identified that also overcome tolerance mechanisms and cause autoimmunity. Delineating these molecular pathways could lead to the development of much needed new therapeutic targets in these complex diseases.


Subject(s)
Autoimmune Diseases , Autoimmunity , Protein-Tyrosine Kinases/metabolism , Animals , Humans , Immune Tolerance , Mice , Receptors, Antigen, T-Cell/metabolism , Thymocytes , Thymus Gland
10.
Nat Commun ; 12(1): 5203, 2021 09 01.
Article in English | MEDLINE | ID: mdl-34471141

ABSTRACT

Aurora kinase A (AURKA) has emerged as a drug target for glioblastoma (GBM). However, resistance to therapy remains a critical issue. By integration of transcriptome, chromatin immunoprecipitation sequencing (CHIP-seq), Assay for Transposase-Accessible Chromatin sequencing (ATAC-seq), proteomic and metabolite screening followed by carbon tracing and extracellular flux analyses we show that genetic and pharmacological AURKA inhibition elicits metabolic reprogramming mediated by inhibition of MYC targets and concomitant activation of Peroxisome Proliferator Activated Receptor Alpha (PPARA) signaling. While glycolysis is suppressed by AURKA inhibition, we note an increase in the oxygen consumption rate fueled by enhanced fatty acid oxidation (FAO), which was accompanied by an increase of Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α). Combining AURKA inhibitors with inhibitors of FAO extends overall survival in orthotopic GBM PDX models. Taken together, these data suggest that simultaneous targeting of oxidative metabolism and AURKAi might be a potential novel therapy against recalcitrant malignancies.


Subject(s)
Aurora Kinase A/genetics , Aurora Kinase A/metabolism , Glioblastoma/genetics , Glioblastoma/metabolism , Warburg Effect, Oncologic , Cell Line, Tumor , Cell Proliferation , Fatty Acids/metabolism , Glycolysis/drug effects , Humans , PPAR alpha/metabolism , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/metabolism , Proteomics , Signal Transduction/drug effects , Transcriptome , Warburg Effect, Oncologic/drug effects
11.
Oncotarget ; 12(13): 1309-1313, 2021 Jun 22.
Article in English | MEDLINE | ID: mdl-34194627

ABSTRACT

The concept that tumor cells demand a distinct form of metabolism was appreciated almost a century ago when the German biochemist Otto Warburg realized that tumor cells heavily utilize glucose and produce lactic acid while relatively reducing oxidative metabolism. How this phenomenon is orchestrated and regulated is only partially understood and seems to involve certain transcription factors, including c-Myc, HIF1A and others. The epigenome eintails the posttranslational modification of histone proteins which in turn are involved in regulation of transcription. Recently, it was found that cis-regulatory elements appear to facilitate the Warburg effects since several genes encoding for glycolysis and associated pathways are surrounded by enhancer/super-enhancer regions. Disruption of these regions by FDA-approved HDAC inhibitors suppressed the transcription of these genes and elicited a reversal of the Warburg effect with activation of transcription factors facilitating oxidative energy metabolism with increases in transcription factors that are part of the PPARA family. Therefore, combined targeting of HDACs and oxidative metabolism suppressed tumor growth in patient-derived xenograft models of solid tumors, including glioblastoma.

12.
Cells ; 10(7)2021 06 30.
Article in English | MEDLINE | ID: mdl-34209035

ABSTRACT

Glioblastoma is a high-grade glial neoplasm with a patient survival of 12-18 months. Therefore, the identification of novel therapeutic targets is an urgent need. RAB38 is a GTPase protein implicated in regulating cell proliferation and survival in tumors. The role of RAB38 in glioblastoma is relatively unexplored. Here, we test the hypothesis that RAB38 regulates glioblastoma growth using human glioblastoma cell lines. We found that genetic interference of RAB38 resulted in a decrease in glioblastoma growth through inhibition of proliferation and cell death induction. Transcriptome analysis showed that RAB38 silencing leads to changes in genes related to mitochondrial metabolism and intrinsic apoptosis (e.g., Bcl-xL). Consistently, rescue experiments demonstrated that loss of RAB38 causes a reduction in glioblastoma viability through downregulation of Bcl-xL. Moreover, RAB38 knockdown inhibited both glycolysis and oxidative phosphorylation. Interference with RAB38 enhanced cell death induced by BH3-mimetics. RAB38 antagonists are under development, but not yet clinically available. We found that FDA-approved statins caused a rapid reduction in RAB38 protein levels, increased cell death, and phenocopied some of the molecular changes elicited by loss of RAB38. In summary, our findings suggest that RAB38 is a potential therapeutic target for glioblastoma treatment.


Subject(s)
Energy Metabolism , Glioblastoma/metabolism , Glioblastoma/pathology , rab GTP-Binding Proteins/metabolism , Astrocytes/drug effects , Astrocytes/metabolism , Biomarkers, Tumor/metabolism , Cell Cycle/drug effects , Cell Death/drug effects , Cell Line, Tumor , Cell Survival/drug effects , Down-Regulation/drug effects , Energy Metabolism/drug effects , Gene Silencing/drug effects , Humans , Mitochondria/metabolism , Myeloid Cell Leukemia Sequence 1 Protein/metabolism , Prognosis , Proto-Oncogene Proteins c-myc/metabolism , Simvastatin/pharmacology , bcl-X Protein/metabolism
13.
Cancers (Basel) ; 13(10)2021 May 20.
Article in English | MEDLINE | ID: mdl-34065488

ABSTRACT

Transcription factors are key players underlying cancer formation, growth, survival, metastasis and treatment resistance, yet few drugs exist to directly target them. Here, we characterized the in vitro and in vivo anti-cancer efficacy of novel synthetic cell-penetrating peptides (Bpep and Dpep) designed to interfere with the formation of active leucine-zipper-based dimers by CEBPB and CEBPD, transcription factors implicated in multiple malignancies. Both peptides similarly promoted apoptosis of multiple tumor lines of varying origins, without such effects on non-transformed cells. Combined with other treatments (radiation, Taxol, chloroquine, doxorubicin), the peptides acted additively to synergistically and were fully active on Taxol-resistant cells. The peptides suppressed expression of known direct CEBPB/CEBPD targets IL6, IL8 and asparagine synthetase (ASNS), supporting their inhibition of transcriptional activation. Mechanisms by which the peptides trigger apoptosis included depletion of pro-survival survivin and a required elevation of pro-apoptotic BMF. Bpep and Dpep significantly slowed tumor growth in mouse models without evident side effects. Dpep significantly prolonged survival in xenograft models. These findings indicate the efficacy and potential of Bpep and Dpep as novel agents to treat a variety of cancers as mono- or combination therapies.

14.
NPJ Genom Med ; 6(1): 36, 2021 May 28.
Article in English | MEDLINE | ID: mdl-34050178

ABSTRACT

Telomere biology disorders (TBD) are a heterogeneous group of diseases arising from germline mutations affecting genes involved in telomere maintenance. Telomeres are DNA-protein structures at chromosome ends that maintain chromosome stability; their length affects cell replicative potential and senescence. A constellation of bone marrow failure, pulmonary fibrosis, liver cirrhosis and premature greying is suggestive, however incomplete penetrance results in highly variable manifestations, with idiopathic pulmonary fibrosis as the most common presentation. Currently, the true extent of TBD burden is unknown as there is no established diagnostic criteria and the disorder often is unrecognised and underdiagnosed. There is no gold standard for measuring telomere length and not all TBD-related mutations have been identified. There is no specific cure and the only treatment is organ transplantation, which has poor outcomes. This review summarises the current literature and discusses gaps in understanding and areas of need in managing TBD.

15.
J Exp Med ; 218(7)2021 07 05.
Article in English | MEDLINE | ID: mdl-33974042

ABSTRACT

T cell anergy is an important peripheral tolerance mechanism. We studied how T cell anergy is established using an anergy model in which the Zap70 hypermorphic mutant W131A is coexpressed with the OTII TCR transgene (W131AOTII). Anergy was established in the periphery, not in the thymus. Contrary to enriched tolerance gene signatures and impaired TCR signaling in mature peripheral CD4 T cells, CD4SP thymocytes exhibited normal TCR signaling in W131AOTII mice. Importantly, the maintenance of T cell anergy in W131AOTII mice required antigen presentation via MHC-II. We investigated the functional importance of the inhibitory receptor PD-1 and the E3 ubiquitin ligases Cbl-b and Grail in this model. Deletion of each did not affect expression of phenotypic markers of anergic T cells or T reg numbers. However, deletion of Cbl-b, but not Grail or PD-1, in W131AOTII mice restored T cell responsiveness and signaling. Thus, Cbl-b plays an essential role in the establishment and/or maintenance of unresponsiveness in T cell anergy.


Subject(s)
Adaptor Proteins, Signal Transducing/immunology , CD4-Positive T-Lymphocytes/immunology , Proto-Oncogene Proteins c-cbl/immunology , T-Lymphocytes, Regulatory/immunology , Animals , Clonal Anergy/immunology , Immune Tolerance/immunology , Lymphocyte Activation/immunology , Male , Mice , Mice, Transgenic , Peripheral Tolerance/immunology , Programmed Cell Death 1 Receptor/immunology , Signal Transduction/immunology , Ubiquitin-Protein Ligases/immunology , ZAP-70 Protein-Tyrosine Kinase/immunology
16.
Plant Foods Hum Nutr ; 75(4): 656-658, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33009632

ABSTRACT

Bitter gourd fruits contain high amounts of charantin, stigmasterol glucoside and ß-sitosterol glucoside, which have been shown to provide health benefits for humans. However, the bitterness of the fruit means they are rarely consumed. This study aimed to assess the effects of Lactobacillus plantarum fermentation, which has previously been reported to effectively reduce bitterness, on the contents of these compounds. The current results suggest that Lactobacillus plantarum fermentation should be considered as a potential approach to enhance the levels of these compounds in bitter gourd juice.


Subject(s)
Lactobacillus plantarum , Momordica charantia , Fermentation , Glucosides , Humans , Sitosterols , Stigmasterol/analogs & derivatives
17.
Cancers (Basel) ; 12(8)2020 Aug 01.
Article in English | MEDLINE | ID: mdl-32752193

ABSTRACT

Apoptotic resistance remains a hallmark of glioblastoma (GBM), the most common primary brain tumor in adults, and a better understanding of this process may result in more efficient treatments. By utilizing chromatin immunoprecipitation with next-generation sequencing (CHIP-seq), we discovered that GBMs harbor a super enhancer around the Mcl-1 locus, a gene that has been known to confer cell death resistance in GBM. We utilized THZ1, a known super-enhancer blocker, and BH3-mimetics, including ABT263, WEHI-539, and ABT199. Combined treatment with BH3-mimetics and THZ1 led to synergistic growth reduction in GBM models. Reduction in cellular viability was accompanied by significant cell death induction with features of apoptosis, including disruption of mitochondrial membrane potential followed by activation of caspases. Mechanistically, THZ1 elicited a profound disruption of the Mcl-1 enhancer region, leading to a sustained suppression of Mcl-1 transcript and protein levels, respectively. Mechanism experiments suggest involvement of Mcl-1 in the cell death elicited by the combination treatment. Finally, the combination treatment of ABT263 and THZ1 resulted in enhanced growth reduction of tumors without induction of detectable toxicity in two patient-derived xenograft models of GBM in vivo. Taken together, these findings suggest that combined epigenetic targeting of Mcl-1 along with Bcl-2/Bcl-xL is potentially therapeutically feasible.

18.
Cells ; 9(7)2020 07 10.
Article in English | MEDLINE | ID: mdl-32664214

ABSTRACT

The heterogeneity of glioblastomas, the most common primary malignant brain tumor, remains a significant challenge for the treatment of these devastating tumors. Therefore, novel combination treatments are warranted. Here, we showed that the combined inhibition of TRAP1 by gamitrinib and histone deacetylases (HDAC1/HDAC2) through romidepsin or panobinostat caused synergistic growth reduction of established and patient-derived xenograft (PDX) glioblastoma cells. This was accompanied by enhanced cell death with features of apoptosis and activation of caspases. The combination treatment modulated the levels of pro- and anti-apoptotic Bcl-2 family members, including BIM and Noxa, Mcl-1, Bcl-2 and Bcl-xL. Silencing of Noxa, BAK and BAX attenuated the effects of the combination treatment. At the metabolic level, the combination treatment led to an enhanced reduction of oxygen consumption rate and elicited an unfolded stress response. Finally, we tested whether the combination treatment of gamitrinib and panobinostat exerted therapeutic efficacy in PDX models of glioblastoma (GBM) in mice. While single treatments led to mild to moderate reduction in tumor growth, the combination treatment suppressed tumor growth significantly stronger than single treatments without induction of toxicity. Taken together, we have provided evidence that simultaneous targeting of TRAP1 and HDAC1/2 is efficacious to reduce tumor growth in model systems of glioblastoma.


Subject(s)
Antineoplastic Agents/therapeutic use , Glioblastoma/drug therapy , HSP90 Heat-Shock Proteins/metabolism , Histone Deacetylase 1/metabolism , Histone Deacetylase 2/metabolism , Histone Deacetylase Inhibitors/therapeutic use , Animals , Blotting, Western , Cell Line, Tumor , Cell Survival/drug effects , Chromatin Immunoprecipitation , Electron Transport/drug effects , Flow Cytometry , Glioblastoma/metabolism , Humans , In Situ Nick-End Labeling , Mice , Proto-Oncogene Proteins c-bcl-2/metabolism , RNA, Small Interfering/genetics , RNA, Small Interfering/metabolism , Real-Time Polymerase Chain Reaction , Xenograft Model Antitumor Assays
19.
Sci Rep ; 10(1): 12497, 2020 07 27.
Article in English | MEDLINE | ID: mdl-32719338

ABSTRACT

Acute lung injury (ALI), a common condition in critically ill patients, has limited treatments and high mortality. Aging is a risk factor for ALI. Sirtuins (SIRTs), central regulators of the aging process, decrease during normal aging and in aging-related diseases. We recently showed decreased SIRT7 expression in lung tissues and fibroblasts from patients with pulmonary fibrosis compared to controls. To gain insight into aging-related mechanisms in ALI, we investigated the effects of SIRT7 depletion on lipopolysaccharide (LPS)-induced inflammatory responses and endothelial barrier permeability in human primary pulmonary endothelial cells. Silencing SIRT7 in pulmonary artery or microvascular endothelial cells attenuated LPS-induced increases in ICAM1, VCAM1, IL8, and IL6 and induced endomesenchymal transition (EndoMT) with decreases in VE-Cadherin and PECAM1 and increases in collagen, alpha-smooth muscle actin, TGFß receptor 1, and the transcription factor Snail. Loss of endothelial adhesion molecules was accompanied by increased F-actin stress fibers and increased endothelial barrier permeability. Together, these results show that an aging phenotype induced by SIRT7 deficiency promotes EndoMT with impaired inflammatory responses and dysfunction of the lung vascular barrier.


Subject(s)
Capillary Permeability , Endothelial Cells/pathology , Epithelium/pathology , Inflammation/metabolism , Lung/pathology , Sirtuins/deficiency , Adult , Animals , Bleomycin , Cell Membrane Permeability , Cells, Cultured , Endothelial Cells/metabolism , Gene Expression Regulation , Gene Silencing , Humans , Inflammation Mediators/metabolism , Lipopolysaccharides , Mice, Inbred C57BL , NF-kappa B/metabolism , Pulmonary Fibrosis/genetics , Pulmonary Fibrosis/pathology , Pulmonary Fibrosis/physiopathology , RNA, Messenger/genetics , RNA, Messenger/metabolism , Signal Transduction , Sirtuins/genetics , Sirtuins/metabolism , Transforming Growth Factor beta/metabolism
20.
Metabolites ; 10(6)2020 Jun 15.
Article in English | MEDLINE | ID: mdl-32549240

ABSTRACT

The methanol extracts of nine popular cultivated Vietnamese rice cultivars (Oryza sativa L.cv. OM 2395, 5451, 6976, 380, 5930, 4498, 3536, N406, and 7347) were used to explore their allelopathic potential on barnyardgrass (Echinochola crus-galli L.). At 0.1 g mL-1, OM 5930, OM 4498, and OM 6976 correlatively possessed greatest phytotoxicity on barnyardgrass shoot (98.77%, 90.75%, and 87.17%) and root (99.39%, 92.83%, and 86.56%) growth. The following study aimed to detect previously-known allelochemicals in those rice using XCMS online cloud-based metabolomics platform. Twenty allelochemicals were semi-quantified and seven of them were detected predominantly and five was putatively confirmed in OM 5930 (mg/ 100g fresh rice) as salicylic acid (5.0076), vanillic acid (0.1246), p-coumaric acid (0.1590), 2,4-dimethoxybenzoic acid (0.1045), and cinnamic acid (3.3230). These compounds were active at concentrations greater than 0.5 mM and the average EC50 were 1.24 mM. The results indicated that OM 5930 may use as promising candidates in weed biological control for rice production.

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