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1.
Biomedicines ; 12(6)2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38927583

RESUMO

Glioblastoma multiforme (GBM) is one of the most aggressive forms of brain tumor, characterized by a daunting prognosis with a life expectancy hovering around 12-16 months. Despite a century of relentless research, only a select few drugs have received approval for brain tumor treatment, largely due to the formidable barrier posed by the blood-brain barrier. The current standard of care involves a multifaceted approach combining surgery, irradiation, and chemotherapy. However, recurrence often occurs within months despite these interventions. The formidable challenges of drug delivery to the brain and overcoming therapeutic resistance have become focal points in the treatment of brain tumors and are deemed essential to overcoming tumor recurrence. In recent years, a promising wave of advanced treatments has emerged, offering a glimpse of hope to overcome the limitations of existing therapies. This review aims to highlight cutting-edge technologies in the current and ongoing stages of development, providing patients with valuable insights to guide their choices in brain tumor treatment.

2.
Reprod Health ; 21(1): 34, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38468301

RESUMO

BACKGROUND: Human Immunodeficiency Virus (HIV) remains a significant public health concern worldwide. Women living with HIV/AIDS (WLHA) have the additional and unique need to seek sexual and reproductive health services. WLHA's maternal health journeys can be shaped by the cultural norms and resources that exist in their society. This study sought to understand if and how WLHA's family planning, pregnancy, and motherhood experiences could be influenced by the patriarchal culture, gender roles, and HIV stigma in Vietnam, specifically. METHODS: Between December 2021 and March 2022, 30 WLHA with diverse socioeconomic backgrounds and childbirth experiences were interviewed in Hanoi, Vietnam. These semi-structured interviews covered topics including HIV stigma, gender norms, pregnancy experiences, and child-rearing challenges. Interviews were audio recorded, transcribed, and analysed using ATLAS.ti. RESULTS: Qualitative analyses of participant quotes revealed how limited information on one's health prospects and reproductive options posed a significant challenge to family planning. Societal and familial expectations as well as economic circumstances also influenced reproductive decision-making. WLHA often encountered substandard healthcare during pregnancy, labor, and delivery. Stigma and lack of provider attentiveness resulted in cases where women were denied pain relief and other medical services. Communication breakdowns resulted in failure to administer antiretroviral therapy for newborns. Motherhood for WLHA was shadowed by concerns for not only their own health, but also the wellbeing of their children, as HIV stigma affected their children at school and in society as well. Many WLHA highlighted the constructive or destructive role that family members could play in their childbirth decision-making and care-giving experiences. CONCLUSIONS: Overall, this study underscores the complex ways that cultural expectations, family support, and stigma in healthcare impact WLHA. Efforts to educate and engage families and healthcare providers are warranted to better understand and address the needs of WLHA, ultimately improving their reproductive and maternal health.


HIV-related stigma and discrimination have consequential impacts on health and quality of life for women living with HIV (WLHA). WLHA in Vietnam must navigate the additional challenges of a traditionally patriarchal and hierarchical society. Women typically face less educational and occupational opportunities and are often expected to defer to expectations of family and virtue. Stigma among family members, friends, employers, and healthcare providers poses a significant challenge to WLHA autonomy, especially as it relates to their reproductive health decision-making and maternal health experiences. This study aims to better understand the experiences of WLHA throughout family planning, pregnancy, and motherhood. The findings will hopefully shed light on strategies to empower WLHA and to combat HIV- and gender-based stigma not only in Vietnam, but also globally.


Assuntos
Síndrome da Imunodeficiência Adquirida , Infecções por HIV , Gravidez , Humanos , Feminino , Recém-Nascido , HIV , Saúde Materna , Vietnã/epidemiologia , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Pesquisa Qualitativa
3.
Nucleic Acids Res ; 52(9): 5016-5032, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38471819

RESUMO

Viruses are master remodelers of the host cell environment in support of infection and virus production. For example, viruses typically regulate cell gene expression through modulating canonical cell promoter activity. Here, we show that Epstein Barr virus (EBV) replication causes 'de novo' transcription initiation at 29674 new transcription start sites throughout the cell genome. De novo transcription initiation is facilitated in part by the unique properties of the viral pre-initiation complex (vPIC) that binds a TATT[T/A]AA, TATA box-like sequence and activates transcription with minimal support by additional transcription factors. Other de novo promoters are driven by the viral transcription factors, Zta and Rta and are influenced by directional proximity to existing canonical cell promoters, a configuration that fosters transcription through existing promoters and transcriptional interference. These studies reveal a new way that viruses interact with the host transcriptome to inhibit host gene expression and they shed light on primal features driving eukaryotic promoter function.


Assuntos
Infecções por Vírus Epstein-Barr , Herpesvirus Humano 4 , Iniciação da Transcrição Genética , Replicação Viral , Humanos , Herpesvirus Humano 4/fisiologia , Interações Hospedeiro-Patógeno , Regiões Promotoras Genéticas , TATA Box , Fatores de Transcrição/metabolismo , Sítio de Iniciação de Transcrição , Transcrição Gênica , Proteínas Virais/metabolismo , Proteínas Virais/genética , Infecções por Vírus Epstein-Barr/metabolismo , Infecções por Vírus Epstein-Barr/virologia
4.
Phys Chem Chem Phys ; 25(46): 31936-31947, 2023 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-37974519

RESUMO

This study provides a detailed understanding of how the reaction between CH3NH, one of the primary products of the CH3NH2 + OH/Cl reactions, and NOx occurs in the atmosphere since the reaction is expected to be a dominant sink for the tropospheric CH3NH radical. First, we focus on the reaction of the aminyl radical CH3NH with NO2, complementing the known reaction between CH3NH and NO, to provide the overall picture of the CH3NH + NOx system. The reaction was meticulously examined across the extended range of temperature (298-2000 K) and pressure (0.76-76 000 torr) using quantum chemistry calculations and kinetic modeling based on the framework of the Rice-Ramsperger-Kassel-Marcus (RRKM)-based master equation. Highly correlated electronic structure calculations unveil that the intricate reaction mechanism of the CH3NH + NO2 reaction, which can proceed through O-addition or N-addition to form NO2, encompasses numerous steps, channels, and various intermediates and products. The temperature-/pressure-dependent kinetic behaviors and product distribution of the CH3NH + NO2 reaction are revealed under atmospheric and combustion conditions. The main products under atmospheric conditions are found to be CH3NHO and NO, as well as CH3NHNO2, while under combustion conditions, the primary products are only CH3NHO and NO. Given its stability under ambient conditions, CH3NHNO2, a nitramine, is believed to have the potential to induce DNA damage, which can ultimately result in severe cancers. Secondly, by building upon prior research on the CH3NH + NO system, this study shows that the reaction of CH3NH with NOx holds greater importance in urban areas with elevated NOx emissions than other oxidants like O2. Furthermore, this reaction occurs swiftly and results in the creation of various compounds, such as the carcinogenic nitrosamine (CH3NHNO), carcinogenic nitramine (CH3NHNO2), CH3NNOH, (CH3NN + H2O) and (CH3NHO + NO).

5.
Nat Commun ; 14(1): 1187, 2023 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-36864031

RESUMO

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.


Assuntos
Ferroptose , Glioma , Humanos , Animais , Camundongos , Metionina , Cisteína , Proteômica , Racemetionina , Glioma/tratamento farmacológico
6.
bioRxiv ; 2023 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-36865302

RESUMO

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.

7.
Cells ; 11(19)2022 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-36230918

RESUMO

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.


Assuntos
Glioblastoma , Aminoácidos/metabolismo , Ácidos Graxos/uso terapêutico , Glioblastoma/metabolismo , Glucose , Humanos , Ácido Láctico/metabolismo , Fosforilação Oxidativa
8.
Cell ; 185(14): 2591-2608.e30, 2022 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-35803246

RESUMO

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.


Assuntos
Neoplasias Encefálicas , Melanoma , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/secundário , Linfócitos T CD8-Positivos/patologia , Ecossistema , Humanos , RNA-Seq
9.
J Biol Chem ; 298(5): 101907, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35398093

RESUMO

The fat mass and obesity-associated FTO protein catalyzes demethylation of the N6-methyladenosine, an epigenetic mark that controls several metabolic pathways by modulating the transcription, translation, and cellular localization of RNA molecules. Since the discovery that its overexpression links to the development of obesity and cancer, FTO was the target of screening campaigns and structure-based drug design efforts. Although several FTO inhibitors were generated, these often lack potency or selectivity. Herein, we investigate the structure and dynamics of human FTO in solution. We show that the structure of the catalytic N-terminal domain is unstable in the absence of the C-terminal domain, which explains why the isolated N-terminal domain is incompetent for catalysis and suggests that the domain interaction represents a target for the development of specific inhibitors. Then, by using NMR relaxation measurements, we show that the interface between the FTO structural domains, the active site, and several peripheral loops undergo conformational dynamics on both the picosecond-nanosecond and microsecond-millisecond timescales. Consistent with this, we found that the backbone amide residual dipolar couplings measured for FTO in phage pf1 are inconsistent with the static crystal structure of the enzyme. Finally, we generated a conformational ensemble for apo FTO that satisfies the solution NMR data by combining the experimental residual dipolar couplings with accelerated molecular dynamics simulations. Altogether, the structural ensemble reported in this work provides an atomic-resolution model of apo FTO and reveals transient surface pockets at the domain interface that represent potential targets for the design of allosteric inhibitors.


Assuntos
Dioxigenase FTO Dependente de alfa-Cetoglutarato/química , Desenho de Fármacos , Simulação de Dinâmica Molecular , Dioxigenase FTO Dependente de alfa-Cetoglutarato/antagonistas & inibidores , Domínio Catalítico , Humanos , Espectroscopia de Ressonância Magnética , Obesidade/genética
10.
Clin Cancer Res ; 28(9): 1881-1895, 2022 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-35417530

RESUMO

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.


Assuntos
Glioblastoma , Humanos , Apoptose/genética , Linhagem Celular Tumoral , Proliferação de Células , Endopeptidase Clp/genética , Endopeptidase Clp/metabolismo , Endopeptidase Clp/uso terapêutico , Glioblastoma/tratamento farmacológico , Glioblastoma/genética , Glioblastoma/metabolismo , Histona Desacetilase 1/genética , Inibidores de Histona Desacetilases/farmacologia , Inibidores de Histona Desacetilases/uso terapêutico , Peptídeo Hidrolases/genética , Mutações Sintéticas Letais , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Methods Mol Biol ; 2445: 305-328, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34973000

RESUMO

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.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Neoplasias Encefálicas/patologia , Glioblastoma/patologia , Humanos , Isocitrato Desidrogenase/genética , Isocitrato Desidrogenase/metabolismo , Mutação
12.
Nat Commun ; 12(1): 5203, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34471141

RESUMO

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.


Assuntos
Aurora Quinase A/genética , Aurora Quinase A/metabolismo , Glioblastoma/genética , Glioblastoma/metabolismo , Efeito Warburg em Oncologia , Linhagem Celular Tumoral , Proliferação de Células , Ácidos Graxos/metabolismo , Glicólise/efeitos dos fármacos , Humanos , PPAR alfa/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Proteômica , Transdução de Sinais/efeitos dos fármacos , Transcriptoma , Efeito Warburg em Oncologia/efeitos dos fármacos
13.
Sci Adv ; 7(34)2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34407931

RESUMO

Alkbh5 catalyzes demethylation of the N 6-methyladenosine (m6A), an epigenetic mark that controls several physiological processes including carcinogenesis and stem cell differentiation. The activity of Alkbh5 comprises two coupled reactions. The first reaction involves decarboxylation of α-ketoglutarate (αKG) and formation of a Fe4+═O species. This oxyferryl intermediate oxidizes the m6A to reestablish the canonical base. Despite coupling between the two reactions being required for the correct Alkbh5 functioning, the mechanisms linking dioxygen activation to m6A binding are not fully understood. Here, we use solution NMR to investigate the structure and dynamics of apo and holo Alkbh5. We show that binding of m6A to Alkbh5 induces a metal-centered rearrangement of αKG that increases the exposed area of the metal, making it available for binding O2 Our study reveals the molecular mechanisms underlying activation of Alkbh5, therefore opening new perspectives for the design of novel strategies to control gene expression and cancer progression.


Assuntos
Homólogo AlkB 5 da RNA Desmetilase , Neoplasias , Homólogo AlkB 5 da RNA Desmetilase/genética , Homólogo AlkB 5 da RNA Desmetilase/metabolismo , Diferenciação Celular , Humanos
14.
Cells ; 10(7)2021 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-34209035

RESUMO

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.


Assuntos
Metabolismo Energético , Glioblastoma/metabolismo , Glioblastoma/patologia , Proteínas rab de Ligação ao GTP/metabolismo , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Biomarcadores Tumorais/metabolismo , Ciclo Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Inativação Gênica/efeitos dos fármacos , Humanos , Mitocôndrias/metabolismo , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Prognóstico , Proteínas Proto-Oncogênicas c-myc/metabolismo , Sinvastatina/farmacologia , Proteína bcl-X/metabolismo
15.
Oncotarget ; 12(13): 1309-1313, 2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34194627

RESUMO

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.

16.
Int J Mol Sci ; 22(11)2021 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-34205118

RESUMO

During metastasis, cancer cells that originate from the primary tumor circulate in the bloodstream, extravasate, and form micrometastases at distant locations. Several lines of evidence suggest that specific interactions between cancer cells and endothelial cells, in particular tumor cell adhesion to the endothelium and transendothelial migration, play a crucial role in extravasation. Here we have studied the role of vascular endothelial (VE)-cadherin which is expressed aberrantly by breast cancer cells and might promote such interactions. By comparing different human breast cancer cell lines, we observed that the number of cancer cells that adhered to endothelium correlated with VE-cadherin expression levels. VE-cadherin silencing experiments confirmed that VE-cadherin enhances cancer cell adhesion to endothelial cells. However, in contrast, the number of cancer cells that incorporated into the endothelium was not dependent on VE-cadherin. Thus, it appears that cancer cell adhesion and incorporation are distinct processes that are governed by different molecular mechanisms. When cancer cells incorporated into the endothelial monolayer, they formed VE-cadherin positive contacts with endothelial cells. On the other hand, we also observed tumor cells that had displaced endothelial cells, reflecting either different modes of incorporation, or a temporal sequence where cancer cells first form contact with endothelial cells and then displace them to facilitate transmigration. Taken together, these results show that VE-cadherin promotes the adhesion of breast cancer cells to the endothelium and is involved in the initial phase of incorporation, but not their transmigration. Thus, VE-cadherin might be of relevance for therapeutic strategies aiming at preventing the metastatic spread of breast cancer cells.


Assuntos
Antígenos CD/genética , Neoplasias da Mama/genética , Caderinas/genética , Adesão Celular/genética , Endotélio Vascular/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Técnicas de Cocultura , Endotélio Vascular/patologia , Endotélio Vascular/ultraestrutura , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Células Endoteliais da Veia Umbilical Humana/citologia , Humanos , Imagem Molecular/métodos , Metástase Neoplásica
17.
Cancers (Basel) ; 13(10)2021 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-34065488

RESUMO

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.

18.
J Exp Med ; 218(7)2021 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-33974042

RESUMO

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.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/imunologia , Linfócitos T CD4-Positivos/imunologia , Proteínas Proto-Oncogênicas c-cbl/imunologia , Linfócitos T Reguladores/imunologia , Animais , Anergia Clonal/imunologia , Tolerância Imunológica/imunologia , Ativação Linfocitária/imunologia , Masculino , Camundongos , Camundongos Transgênicos , Tolerância Periférica/imunologia , Receptor de Morte Celular Programada 1/imunologia , Transdução de Sinais/imunologia , Ubiquitina-Proteína Ligases/imunologia , Proteína-Tirosina Quinase ZAP-70/imunologia
19.
Cancers (Basel) ; 12(8)2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32752193

RESUMO

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.

20.
Int J Surg Case Rep ; 73: 285-288, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32721890

RESUMO

INTRODUCTION: Situs inversus totalis (SIT) is an uncommon congenital condition characterized by total transposition of abdominal and thoracic viscera. Performing minimally invasive cardiac surgery on individuals with SIT requires different surgical planning because of the unfamiliar positions of the heart and great vessels. PRESENTATION OF CASE: A 52-year-old female was admitted to our center with palpitations and dyspnea on exertion. Chest X-ray showed dextrocardia. Echocardiography and chest computerized tomography (CT) revealed SIT with severe rheumatic mitral valve disease. DISCUSSION: Pre-operative three-dimensional (3D) chest CT reconstruction was helpful in surgical planning and management of cardiopulmonary bypass (CPB). Mitral valve replacement and concomitant atrial fibrillation (AF) ablation using radiofrequency (RF) energy via left mini-thoracotomy was successfully performed on the patient. CONCLUSION: Minimally invasive approach can be safely and effectively employed in patients with SIT.

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