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1.
Paediatr Neonatal Pain ; 4(2): 61-68, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35719220

RESUMO

Children treated in a pediatric intensive care unit (PICU) are at risk of distress and pain. This study investigated if aromatherapy massage can reduce children's distress and improve comfort. This observational before-after study was performed in a 22-bed PICU in Cape Town, South Africa. The aromatherapy massage consisted of soft massaging using the "M-technique" and a 1% blend of essential oils of Lavender (Lavandula angustifolia), German Chamomile (Matricatia recutita) and Neroli (Citrus aurantium) mixed with a grapeseed carrier oil. All present children were eligible, except those who had recently returned, were asleep or deemed unstable. The primary outcome was distress measured with the COMFORT-Behavior scale (COMFORT-B). Secondary outcomes were heart rate, oxygen saturation (SatO2), the Numeric Rating Scale (NRS)-Anxiety and pain assessed by the NRS-Pain scale. Outcomes variables were evaluated with Wilcoxon signed-rank test and multiple regression analysis. The intervention was applied to 111 children, fifty-one of whom (45.9%) were younger than three years old. The group median COMFORT-B score before intervention was 15 (IQR 12-19), versus 10 (IQR 6-14) after intervention. Heart rate and NRS-Anxiety were significantly lower after the intervention (P < 0.001). Multiple regression analysis showed that interrupted massages were less effective than the uninterrupted massages. Parental presence did not influence the outcome variables. We did not find a significant change on the NRS-Pain scale or for SatO2. Aromatherapy massage appears beneficial in reducing distress, as measured by the COMFORT-B scale, heart rate and the NRS-Anxiety scale, in critically ill children. Thus, the potential of aromatherapy in clinical practice deserves further consideration.

2.
Cancers (Basel) ; 11(6)2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-31212989

RESUMO

Circulating tumor cells (CTCs) hold great potential to answer key questions of how non-small cell lung cancer (NSCLC) evolves and develops resistance upon anti-PD-1/PD-L1 treatment. Currently, their clinical utility in NSCLC is compromised by a low detection rate with the established, Food and Drug Administration (FDA)-approved, EpCAM-based CellSearch® System. We tested an epitope-independent method (ParsortixTM system) and utilized it to assess PD-L1 expression of CTCs from NSCLC patients. We prospectively collected 127 samples, 97 of which were analyzed with the epitope-independent system in comparison to the CellSearch system. CTCs were determined by immunocytochemistry as intact, nucleated, CD45-, pankeratins (K)+ cells. PD-L1 status of CTCs was evaluated from 89 samples. With the epitope-independent system, ≥1 CTC per blood sample was detected in 59 samples (61%) compared to 31 samples (32%) with the EpCAM-based system. Upon PD-L1 staining, 47% of patients harbored only PD-L1+CTCs, 47% had PD-L1+ and PD-L1-CTCs, and only 7% displayed exclusively PD-L1-CTCs. The percentage of PD-L1+CTCs did not correlate with the percentage of PD-L1+ in biopsies determined by immunohistochemistry (p = 0.179). Upon disease progression, all patients showed an increase in PD-L1+CTCs, while no change or a decrease in PD-L1+CTCs was observed in responding patients (n = 11; p = 0.001). Our data show a considerable heterogeneity in the PD-L1 status of CTCs from NSCLC patients. An increase of PD-L1+CTCs holds potential to predict resistance to PD-1/PD-L1 inhibitors.

3.
PLoS One ; 14(4): e0214610, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30969984

RESUMO

Glycogen synthase kinase-3 (GSK3) is over-expressed and hyperactivated in non-small cell lung carcinoma (NSCLC) and plays a role in ensuring the correct alignment of chromosomes on the metaphase plate during mitosis through regulation of microtubule stability. This makes the enzyme an attractive target for cancer therapy. We examined the effects of a selective cell-permeant GSK3 inhibitor (CHIR99021), used alone or in combination with paclitaxel, using an in vitro cell growth assay, a quantitative chromosome alignment assay, and a tumor xenograft model. CHIR99021 inhibits the growth of human H1975 and H1299 NSCLC cell lines in a synergistic manner with paclitaxel. CHIR99021 and paclitaxel promoted a synergistic defect in chromosomal alignment when compared to each compound administered as monotherapy. Furthermore, we corroborated our in vitro findings in a mouse tumor xenograft model. Our results demonstrate that a GSK3 inhibitor and paclitaxel act synergistically to inhibit the growth of NSCLC cells in vitro and in vivo via a mechanism that may involve converging modes of action on microtubule spindle stability and thus chromosomal alignment during metaphase. Our findings provide novel support for the use of the GSK3 inhibitor, CHIR99021, alongside taxol-based chemotherapy in the treatment of human lung cancer.


Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Quinase 3 da Glicogênio Sintase/metabolismo , Neoplasias Pulmonares/tratamento farmacológico , Paclitaxel/uso terapêutico , Piridinas/uso terapêutico , Pirimidinas/uso terapêutico , Animais , Antineoplásicos Fitogênicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Aberrações Cromossômicas/efeitos dos fármacos , Sinergismo Farmacológico , Quimioterapia Combinada , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Quinase 3 da Glicogênio Sintase/genética , Humanos , Masculino , Camundongos , Camundongos Nus , Paclitaxel/farmacologia , Piridinas/farmacologia , Pirimidinas/farmacologia , Interferência de RNA , RNA Interferente Pequeno/metabolismo
4.
Adv Drug Deliv Rev ; 125: 102-121, 2018 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-29355669

RESUMO

The CellSearch® system (CS) enables standardized enrichment and enumeration of circulating tumor cells (CTCs) that are repeatedly assessable via non-invasive "liquid biopsy". While the association of CTCs with poor clinical outcome for cancer patients has clearly been demonstrated in numerous clinical studies, utilizing CTCs for the identification of therapeutic targets, stratification of patients for targeted therapies and uncovering mechanisms of resistance is still under investigation. Here, we comprehensively review the current benefits and drawbacks of clinical CTC analyses for patients with metastatic and non-metastatic tumors. Furthermore, the review focuses on approaches beyond CTC enumeration that aim to uncover therapeutically relevant antigens, genomic aberrations, transcriptional profiles and epigenetic alterations of CTCs at a single cell level. This characterization of CTCs may shed light on the heterogeneity and genomic landscapes of malignant tumors, an understanding of which is highly important for the development of new therapeutic strategies.


Assuntos
Biomarcadores Tumorais/sangue , Separação Celular , Neoplasias/diagnóstico , Células Neoplásicas Circulantes/patologia , Humanos
5.
Burns ; 44(1): 99-107, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29089207

RESUMO

IMPORTANCE: In a previous observational study we found that massage therapy reduced anxiety and stress in pediatric burn patients. We aimed to test this effect in a randomized controlled trial. OBJECTIVE: To determine whether (1) aromatherapy massage can provide relaxation to hospitalized children with burns; (2) massage with aromatherapy oil is more effective than without; and (3) massage sessions are more effective when repeated. DESIGN, SETTING, AND PARTICIPANTS: Randomized controlled clinical trial with 3 arms conducted in a burns unit from April 2013 to December 2014 in Cape Town, South Africa. INTERVENTIONS: Massage with carrier oil, massage with aromatherapy oil, and standard nursing care only. MAIN OUTCOMES AND MEASURES: Scores on the Muscle Tension Inventory (MTI) and Behavioral Relaxation Scale (BRS) to assess level of relaxation. Scores on the COMFORT behaviour scale and Numeric Rating Scale Distress to assess level of distress. Secondary outcomes were heart rate and oxygen saturation levels. Linear mixed models were used to determine the effect of condition and session number (1 to a maximum of 5 sessions per child) correcting for baseline outcomes of COMFORT behaviour scores and heart rates after sessions. Secondary analyses included the addition of sex, age, and total body surface area (TBSA) burned as covariates. RESULTS: We included 284 children aged 5 weeks to 13 years with TBSA burned between 10 and 45%. Two-thirds (65.5%) were under the age of 3 years. Mixed model analyses revealed no significant difference in reduction of COMFORT behavior scores (p=0.18), or heart rates (p=0.18) between the three study arms. These outcomes were also not associated with the session number (p=0.92 and p=0.13, respectively). Level of relaxation could not be reliably assessed with the MTI and BRS because 119 patients (41.9%) had bandages covering the larger part of the face, and in 40.1% of cases the child was not in the required position. CONCLUSION AND RELEVANCE: Massage therapy with or without essential oil was not effective in reducing distress behavior or heart rate in hospitalized children with burns. Evaluating the effectiveness of massage in terms of relaxation proved difficult in young children. TRIAL REGISTRATION: The Netherlands National Trial Registry: NRT3929.


Assuntos
Queimaduras/psicologia , Queimaduras/terapia , Massagem/métodos , Estresse Psicológico/terapia , Adolescente , Ansiedade/terapia , Aromaterapia , Criança , Pré-Escolar , Feminino , Frequência Cardíaca/fisiologia , Humanos , Lactente , Masculino , Oxigênio/sangue , Medição da Dor , Óleos de Plantas/uso terapêutico
6.
Transl Lung Cancer Res ; 6(4): 431-443, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28904887

RESUMO

By identifying and tracking genetic changes in primary tumors and metastases, patients can be stratified for the most efficient therapeutic regimen by screening for known biomarkers. However, retrieving tissues biopsies is not always feasible due to tumor location or risk to patient. Therefore, a liquid biopsies approach offers an appealing solution to an otherwise invasive procedure. The rapid growth of the liquid biopsy field has been aided by improvements in the sensitivity and specificity of enrichment assays for isolating circulating tumor cells (CTCs) from normal surrounding blood cells. Furthermore, the identification and molecular characterization of CTCs has been shown in numerous studies to be of diagnostic and prognostic relevance in breast, prostate and colon cancer patients. Despite these advancements, and the highly metastatic nature of lung cancer, it remains a challenge to detect CTCs in advanced non-small cell lung cancer (NSCLC). It may be that loss of epithelial features, in favor of a mesenchymal phenotype, and the highly heterogeneous nature of NSCLC CTCs contribute to their evasion from current detection methods. By identifying a broader spectrum of biomarkers that could better differentiate the various NSCLC CTCs subpopulations, it may be possible to not only improve detection rates but also to shed light on which CTC clones are likely to drive metastatic initiation. Here we review the biology of CTCs and describe a number of proteins and genetic targets which could potentially be utilized for the dissemination of heterogenic subpopulations of CTCs in NSCLC.

7.
PLoS One ; 9(12): e114725, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25486534

RESUMO

BACKGROUND: Glycogen synthase kinase 3 (GSK3) is a central regulator of cellular metabolism, development and growth. GSK3 activity was thought to oppose tumourigenesis, yet recent studies indicate that it may support tumour growth in some cancer types including in non-small cell lung carcinoma (NSCLC). We examined the undefined role of GSK3 protein kinase activity in tissue from human NSCLC. METHODS: The expression and protein kinase activity of GSK3 was determined in 29 fresh frozen samples of human NSCLC and patient-matched normal lung tissue by quantitative immunoassay and western blotting for the phosphorylation of three distinct GSK3 substrates in situ (glycogen synthase, RelA and CRMP-2). The proliferation and sensitivity to the small-molecule GSK3 inhibitor; CHIR99021, of NSCLC cell lines (Hcc193, H1975, PC9 and A549) and non-neoplastic type II pneumocytes was further assessed in adherent culture. RESULTS: Expression and protein kinase activity of GSK3 was elevated in 41% of human NSCLC samples when compared to patient-matched control tissue. Phosphorylation of GSK3α/ß at the inhibitory S21/9 residue was a poor biomarker for activity in tumour samples. The GSK3 inhibitor, CHIR99021 dose-dependently reduced the proliferation of three NSCLC cell lines yet was ineffective against type II pneumocytes. CONCLUSION: NSCLC tumours with elevated GSK3 protein kinase activity may have evolved dependence on the kinase for sustained growth. Our results provide further important rationale for exploring the use of GSK3 inhibitors in treating NSCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/enzimologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Proliferação de Células , Quinase 3 da Glicogênio Sintase/metabolismo , Neoplasias Pulmonares/enzimologia , Neoplasias Pulmonares/patologia , Apoptose , Western Blotting , Estudos de Casos e Controles , Humanos , Técnicas Imunoenzimáticas , Pulmão/enzimologia , Fosforilação , Transdução de Sinais , Células Tumorais Cultivadas
8.
Cell Rep ; 3(5): 1440-8, 2013 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-23643539

RESUMO

The identification of mutated metabolic enzymes in hereditary cancer syndromes has established a direct link between metabolic dysregulation and cancer. Mutations in the Krebs cycle enzyme, fumarate hydratase (FH), predispose affected individuals to leiomyomas, renal cysts, and cancers, though the respective pathogenic roles of mitochondrial and cytosolic FH isoforms remain undefined. On the basis of comprehensive metabolomic analyses, we demonstrate that FH1-deficient cells and tissues exhibit defects in the urea cycle/arginine metabolism. Remarkably, transgenic re-expression of cytosolic FH ameliorated both renal cyst development and urea cycle defects associated with renal-specific FH1 deletion in mice. Furthermore, acute arginine depletion significantly reduced the viability of FH1-deficient cells in comparison to controls. Our findings highlight the importance of extramitochondrial metabolic pathways in FH-associated oncogenesis and the urea cycle/arginine metabolism as a potential therapeutic target.


Assuntos
Fumarato Hidratase/metabolismo , Neoplasias Renais/enzimologia , Animais , Arginina/metabolismo , Ácido Argininossuccínico/metabolismo , Linhagem Celular , Ciclo do Ácido Cítrico , Fumarato Hidratase/deficiência , Fumarato Hidratase/genética , Fumaratos/metabolismo , Rim/enzimologia , Neoplasias Renais/metabolismo , Neoplasias Renais/patologia , Metaboloma , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Mitocôndrias/metabolismo , Mutação , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Ureia/metabolismo
9.
Cell Rep ; 3(3): 689-700, 2013 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-23499446

RESUMO

The gene encoding the Krebs cycle enzyme fumarate hydratase (FH) is mutated in hereditary leiomyomatosis and renal cell cancer (HLRCC). Loss of FH activity causes accumulation of intracellular fumarate, which can directly modify cysteine residues to form 2-succinocysteine through succination. We undertook a proteomic-based screen in cells and renal cysts from Fh1 (murine FH)-deficient mice and identified 94 protein succination targets. Notably, we identified the succination of three cysteine residues in mitochondrial Aconitase2 (ACO2) crucial for iron-sulfur cluster binding. We show that fumarate exerts a dose-dependent inhibition of ACO2 activity, which correlates with increased succination as determined by mass spectrometry, possibly by interfering with iron chelation. Importantly, we show that aconitase activity is impaired in FH-deficient cells. Our data provide evidence that succination, resulting from FH deficiency, targets and potentially alters the function of multiple proteins and may contribute to the dysregulated metabolism observed in HLRCC.


Assuntos
Aconitato Hidratase/metabolismo , Fumarato Hidratase/deficiência , Fumarato Hidratase/metabolismo , Neoplasias Renais/metabolismo , Leiomiomatose/metabolismo , Mitocôndrias/metabolismo , Síndromes Neoplásicas Hereditárias/metabolismo , Ácido Succínico/metabolismo , Aconitato Hidratase/antagonistas & inibidores , Animais , Linhagem Celular , Cisteína/metabolismo , Fumarato Hidratase/genética , Fumaratos/metabolismo , Humanos , Ferro/metabolismo , Camundongos , Camundongos Transgênicos , Proteoma/metabolismo , Neoplasias Cutâneas , Neoplasias Uterinas
10.
Mol Cell Biol ; 32(15): 3081-94, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22645311

RESUMO

Loss-of-function mutations of the tumor suppressor gene encoding fumarase (FH) occur in individuals with hereditary leiomyomatosis and renal cell cancer syndrome (HLRCC). We found that loss of FH activity conferred protection from apoptosis in normal human renal cells and fibroblasts. In FH-defective cells, both hypoxia-inducible factor 1α (HIF-1α) and HIF-2α accumulated, but they were not required for apoptosis protection. Conversely, AMP-activated protein kinase (AMPK) was activated and required, as evidenced by the finding that FH inactivation failed to protect AMPK-null mouse embryo fibroblasts (MEFs) and AMPK-depleted human renal cells. Activated AMPK was detected in renal cysts, which occur in mice with kidney-targeted deletion of Fh1 and in kidney cancers of HLRCC patients. In Fh1-null MEFs, AMPK activation was sustained by fumarate accumulation and not by defective energy metabolism. Addition of fumarate and succinate to kidney cells led to extracellular signal-regulated kinase 1/2 (ERK1/2) and AMPK activation, probably through a receptor-mediated mechanism. These findings reveal a new mechanism of tumorigenesis due to FH loss and an unexpected pro-oncogenic role for AMPK that is important in considering AMPK reactivation as a therapeutic strategy against cancer.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Fumarato Hidratase/genética , Fumaratos/metabolismo , Proteínas Quinases Ativadas por AMP/deficiência , Proteínas Quinases Ativadas por AMP/genética , Animais , Apoptose , Fatores de Transcrição Hélice-Alça-Hélice Básicos/biossíntese , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Linhagem Celular , Fumarato Hidratase/deficiência , Fumarato Hidratase/metabolismo , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/biossíntese , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Neoplasias Renais/genética , Leiomiomatose/genética , Camundongos , Proteína Quinase 1 Ativada por Mitógeno/biossíntese , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/biossíntese , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Síndromes Neoplásicas Hereditárias/genética , Interferência de RNA , RNA Interferente Pequeno , Espécies Reativas de Oxigênio/análise , Transdução de Sinais , Neoplasias Cutâneas , Proteínas Supressoras de Tumor/deficiência , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo , Neoplasias Uterinas
11.
Burns ; 38(6): 840-5, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22305182

RESUMO

OBJECTIVE: This observational pilot study investigated effects of aromatherapy massage in paediatric burn patients. METHODS: The setting was a 17 beds level I burn unit in Cape Town, South Africa. Between January and October 2009 heart rates and respiratory rates of patients who underwent aromatherapy massage sessions were read before and after the sessions. Primary outcomes were decline in heart rates and respiratory rates, a sign of relaxation. Behavioural responses (sleep/awake state, facial expression, body posture) were documented as secondary outcomes. RESULTS: A convenience sample of 71 paediatric burn patients (median age 3 years) underwent a total of 126 massage sessions. Mean heart rate decreased significantly from 118 (SD 20) to 109 (SD 21), t=9.8, p<0.001. Mean respiratory rate decreased significantly from 34 (SD 8) to 30 (SD 8), t=10.2, p<0.001. Most massage sessions (92.8%) elicited positive behaviour to the massage, e.g. the child fell asleep, calmed or asked to continue. Nine patients (7.2%) with a median age of 15 months who underwent a single massage session did not show positive behaviour but cried, wriggled or were distressed. CONCLUSIONS: Aromatherapy massage seems to be a helpful nonpharmacological approach to reduce hospitalized paediatric burn patients' distress. Future studies with better research designs and validated outcome measures should confirm our findings.


Assuntos
Ansiedade/prevenção & controle , Aromaterapia/métodos , Queimaduras/terapia , Massagem/métodos , Queimaduras/fisiopatologia , Pré-Escolar , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Projetos Piloto , Estudos Prospectivos , Terapia de Relaxamento/métodos , Taxa Respiratória/fisiologia , África do Sul
12.
Cancer Cell ; 20(4): 524-37, 2011 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-22014577

RESUMO

The Krebs cycle enzyme fumarate hydratase (FH) is a human tumor suppressor whose inactivation is associated with the development of leiomyomata, renal cysts, and tumors. It has been proposed that activation of hypoxia inducible factor (HIF) by fumarate-mediated inhibition of HIF prolyl hydroxylases drives oncogenesis. Using a mouse model, we provide genetic evidence that Fh1-associated cyst formation is Hif independent, as is striking upregulation of antioxidant signaling pathways revealed by gene expression profiling. Mechanistic analysis revealed that fumarate modifies cysteine residues within the Kelch-like ECH-associated protein 1 (KEAP1), abrogating its ability to repress the Nuclear factor (erythroid-derived 2)-like 2 (Nrf2)-mediated antioxidant response pathway, suggesting a role for Nrf2 dysregulation in FH-associated cysts and tumors.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas do Citoesqueleto/metabolismo , Fumarato Hidratase/fisiologia , Fumaratos/metabolismo , Doenças Renais Císticas/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Succinatos/metabolismo , Animais , Antioxidantes/metabolismo , Hipóxia Celular , Fumarato Hidratase/genética , Fumarato Hidratase/metabolismo , Regulação Neoplásica da Expressão Gênica , Fator 1 Induzível por Hipóxia/genética , Fator 1 Induzível por Hipóxia/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch , Doenças Renais Císticas/genética , Camundongos , Pró-Colágeno-Prolina Dioxigenase/metabolismo , Transdução de Sinais
13.
J Pathol ; 225(1): 4-11, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21630274

RESUMO

Germline mutations in the FH gene encoding the Krebs cycle enzyme fumarate hydratase predispose to hereditary leiomyomatosis and renal cell cancer (HLRCC) syndrome. FH-deficient cells and tissues accumulate high levels of fumarate, which may act as an oncometabolite and contribute to tumourigenesis. A recently proposed role for fumarate in the covalent modification of cysteine residues to S-(2-succinyl) cysteine (2SC) (termed protein succination) prompted us to assess 2SC levels in our existing models of HLRCC. Herein, using a previously characterized antibody against 2SC, we show that genetic ablation of FH causes high levels of protein succination. We next hypothesized that immunohistochemistry for 2SC would serve as a metabolic biomarker for the in situ detection of FH-deficient tissues. Robust detection of 2SC was observed in Fh1 (murine FH)-deficient renal cysts and in a retrospective series of HLRCC tumours (n = 16) with established FH mutations. Importantly, 2SC was undetectable in normal tissues (n = 200) and tumour types not associated with HLRCC (n = 1342). In a prospective evaluation of cases referred for genetic testing for HLRCC, the presence of 2SC-modified proteins (2SCP) correctly predicted genetic alterations in FH in every case. In two series of unselected type II papillary renal cancer (PRCC), prospectively analysed by 2SCP staining followed by genetic analysis, the biomarker accurately identified previously unsuspected FH mutations (2/33 and 1/36). The investigation of whether metabolites in other tumour types produce protein modification signature(s) that can be assayed using similar strategies will be of interest in future studies of cancer.


Assuntos
Carcinoma de Células Renais/diagnóstico , Fumarato Hidratase/deficiência , Neoplasias Renais/diagnóstico , Leiomiomatose/diagnóstico , Síndromes Neoplásicas Hereditárias/diagnóstico , Adulto , Idoso , Animais , Biomarcadores Tumorais/deficiência , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinoma de Células Renais/genética , Modelos Animais de Doenças , Feminino , Fumarato Hidratase/genética , Fumarato Hidratase/metabolismo , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Humanos , Neoplasias Renais/genética , Leiomiomatose/genética , Perda de Heterozigosidade , Masculino , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Pessoa de Meia-Idade , Síndromes Neoplásicas Hereditárias/genética , Estudos Prospectivos , Sensibilidade e Especificidade , Ácido Succínico/metabolismo
14.
PLoS One ; 6(1): e16210, 2011 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-21264265

RESUMO

Human 2-oxoglutarate oxygenases catalyse a range of biological oxidations including the demethylation of histone and nucleic acid substrates and the hydroxylation of proteins and small molecules. Some of these processes are centrally involved in regulation of cellular responses to hypoxia. The ALKBH proteins are a sub-family of 2OG oxygenases that are defined by homology to the Escherichia coli DNA-methylation repair enzyme AlkB. Here we report evidence that ALKBH5 is probably unique amongst the ALKBH genes in being a direct transcriptional target of hypoxia inducible factor-1 (HIF-1) and is induced by hypoxia in a range of cell types. We show that purified recombinant ALKBH5 is a bona fide 2OG oxygenase that catalyses the decarboxylation of 2OG but appears to have different prime substrate requirements from those so far defined for other ALKBH family members. Our findings define a new class of HIF-transcriptional target gene and suggest that ALKBH5 may have a role in the regulation of cellular responses to hypoxia.


Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Ácidos Cetoglutáricos/metabolismo , Oxigenases/metabolismo , Homólogo AlkB 5 da RNA Desmetilase , Linhagem Celular , Dioxigenases , Humanos , Hipóxia , Proteínas de Membrana , Proteínas Nucleares/genética , Proteínas Nucleares/fisiologia , Oxigenases/genética , Oxigenases/fisiologia , Ativação Transcricional
15.
Cancer Res ; 70(22): 9153-65, 2010 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-20978192

RESUMO

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is caused by mutations in the Krebs cycle enzyme fumarate hydratase (FH). It has been proposed that "pseudohypoxic" stabilization of hypoxia-inducible factor-α (HIF-α) by fumarate accumulation contributes to tumorigenesis in HLRCC. We hypothesized that an additional direct consequence of FH deficiency is the establishment of a biosynthetic milieu. To investigate this hypothesis, we isolated primary mouse embryonic fibroblast (MEF) lines from Fh1-deficient mice. As predicted, these MEFs upregulated Hif-1α and HIF target genes directly as a result of FH deficiency. In addition, detailed metabolic assessment of these MEFs confirmed their dependence on glycolysis, and an elevated rate of lactate efflux, associated with the upregulation of glycolytic enzymes known to be associated with tumorigenesis. Correspondingly, Fh1-deficient benign murine renal cysts and an advanced human HLRCC-related renal cell carcinoma manifested a prominent and progressive increase in the expression of HIF-α target genes and in genes known to be relevant to tumorigenesis and metastasis. In accord with our hypothesis, in a variety of different FH-deficient tissues, including a novel murine model of Fh1-deficient smooth muscle, we show a striking and progressive upregulation of a tumorigenic metabolic profile, as manifested by increased PKM2 and LDHA protein. Based on the models assessed herein, we infer that that FH deficiency compels cells to adopt an early, reversible, and progressive protumorigenic metabolic milieu that is reminiscent of that driving the Warburg effect. Targets identified in these novel and diverse FH-deficient models represent excellent potential candidates for further mechanistic investigation and therapeutic metabolic manipulation in tumors.


Assuntos
Fumarato Hidratase/deficiência , Fumarato Hidratase/genética , Perfilação da Expressão Gênica , Regulação Enzimológica da Expressão Gênica , Animais , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/patologia , Proliferação de Células , Células Cultivadas , Embrião de Mamíferos/citologia , Feminino , Fibroblastos/citologia , Fibroblastos/metabolismo , Glicólise , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Neoplasias Renais/genética , Neoplasias Renais/metabolismo , Neoplasias Renais/patologia , Leiomiomatose/genética , Leiomiomatose/metabolismo , Leiomiomatose/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Músculo Liso/metabolismo , Músculo Liso/patologia , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patologia , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Cariotipagem Espectral
16.
Hum Mol Genet ; 19(19): 3844-51, 2010 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-20660115

RESUMO

Mutations in the gene encoding the Krebs cycle enzyme fumarate hydratase (FH) predispose to hereditary leiomyomatosis and renal cell cancer in affected individuals. FH-associated neoplasia is characterized by defective mitochondrial function and by upregulation of transcriptional pathways mediated by hypoxia-inducible factor (HIF), although whether and by what means these processes are linked has been disputed. We analysed the HIF pathway in Fh1-/- mouse embryonic fibroblasts (MEFs), in FH-defective neoplastic tissues and in Fh1-/- MEFs re-expressing either wild-type or an extra-mitochondrial restricted form of FH. These experiments demonstrated that upregulation of HIF-1alpha occurs as a direct consequence of FH inactivation. Fh1-/- cells accumulated intracellular fumarate and manifested severe impairment of HIF prolyl but not asparaginyl hydroxylation which was corrected by provision of exogenous 2-oxoglutarate (2-OG). Re-expression of the extra-mitochondrial form of FH in Fh1-/- cells was sufficient to reduce intracellular fumarate and to correct dysregulation of the HIF pathway completely, even in cells that remained profoundly defective in mitochondrial energy metabolism. The findings indicate that upregulation of HIF-1alpha arises from competitive inhibition of the 2-OG-dependent HIF hydroxylases by fumarate and not from disruption of mitochondrial energy metabolism.


Assuntos
Fumarato Hidratase/deficiência , Mitocôndrias/metabolismo , Transdução de Sinais , Animais , Hipóxia Celular , Embrião de Mamíferos/citologia , Fibroblastos/enzimologia , Fibroblastos/patologia , Fumarato Hidratase/metabolismo , Teste de Complementação Genética , Humanos , Hidroxilação , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Camundongos , Modelos Biológicos , Consumo de Oxigênio , Prolina/metabolismo , Processamento de Proteína Pós-Traducional
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