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Sludge treatment reed bed planted (STRB) with Phragmites australis (P.australis) and Arundo donax (A.donax) was assessed in the presence of Eisenia fetida under control condition during the dry season. Worm-planted units were fed with mixed sewage sludge (dry and volatile solids of 29.44 g DS.L-1 and 24.23 g VS.L-1). Sludge loading rates (SLR) of 50, 60, and 70 kg DS m-2 year-1 were examined to assess dewatering efficiency. Surface layers in units with P.australis and A.donax achieved DS of 80 and 81% at a loading rate of 50 kg DS m-2 year-1, while their subsurface DS were 41 and 25%, respectively. Units with A.donax experienced plant loss when subjected to SLR exceeding 60 kg DS m-2 year-1. More than 10 cm of residual sludge accumulated on the top of units after a 2-month final rest. Evapotranspiration was greater in the unit with P.australis (5.23 mm day-1) compared to the unit with A.donax (4.24 mm day-1) while both were fed with 70 kg DS m-2 year-1. Water loss contributions from residual sludge layer, drained water, and evapotranspiration were 3, 46, and 51%, respectively. Units with P.australis indicated 20% higher water loss compared to units with A.donax. Although the drained water quality improved over time, it did not meet standard limits. The residual sludge layer contained macro and micronutrients, and heavy metals with a significant elemental order of N > Ca > P > S > mg > K (N:P:K = 31:8:1), Fe > Na > B > Mn > Mo and Zn > Cr > Cu > Pb > Ni > Cd. Overall, STRB could be a sustainable alternative technology to conventional sewage sludge management techniques.
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This study evaluated the impact of incorporating earthworms (Eisenia fetida) on the drained water quality from a sludge treatment reed bed. The experiment encompassed four setups of treatment beds in two replicates: planted with Arundo donax and addition of earthworms, planted without earthworms, unplanted with earthworms, and treatment bed without plants nor earthworms as control. The units were fed every two weeks with mixed sewage sludge, a blend of primary and secondary sludge over 24 cycles. The mixed sewage sludge had mean dry and volatile solid contents of 24.71 g.DS.L-1 (± 13.67) and 19.14 g.VS.L-1 (± 10.29) resulting a sludge loading rate of 43.59 kg.DS.m-2.year-1 (± 14.49). The inclusion of earthworms in the planted unit reduced release masses of total suspended solids, chemical oxygen demand, nitrate and phosphorous by 43, 45, 75 and 45 % compared to the planted unit. Plant biomass production increased by 43 % with the earthworm presence. The removal efficiency of the units improved after a ramp-up phase (after six months feeding) of which the concentration of TSS, COD and Escherichia coli met limits for water reuse while nitrogen components and phosphorous surpassed the limits. The planted unit with earthworms removed 99 and 99 % of TSS and COD, respectively. Overall, water loss namely through evapotranspiration and earthworm hydration need, positively correlated with pollutant concentration, and earthworm-planted unit had 46 % higher water loss compared to control unit.
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Oligoquetos , Poaceae , Aguas del Alcantarillado , Eliminación de Residuos Líquidos , Calidad del Agua , Oligoquetos/fisiología , Animales , Eliminación de Residuos Líquidos/métodos , Biodegradación Ambiental , Región MediterráneaRESUMEN
A one-year study of sludge treatment reed bed assisted with earthworms (W-STRB) was conducted in a temperate climate. The effects of using Eisenia fetid and Arundo donax on W-STRB water balance (WB) and dewatering efficiency (DE) were investigated. Four different bed configurations were tested: worm-planted (WP), planted (P), worm-control (W), and control (C), duplicated resulting in a total of eight units. The beds received a total of 24 cycles of mixed sewage sludge twice per month (average loading rate: 43.59 kg.DS. m-2.year-1). It was found seasonal variation played a significant role in WB and DE. During the dry season, the thickness of the residual sludge (RS) layer was less than 1 cm, with a dry solid (DS) content of over 80%, in contrast, the wet season indicated an increase in RS thickness to nearly 30 cm (DS < 15 % for all units). The WP unit exhibited the lowest RS accumulation, 22% less than the P, W, and C units. The subsurface layer had a 5% lower volatile solids (VS) content compared to the surface layers. After 132 days of a final resting, WP unit had the highest RS volume reduction of 65 % (DS = 71 % and VS = 53 %) and a RS thickness of 6 cm indicating a 10 % higher stabilization compared to P unit. The population of earthworms was 30% higher in the WP unit compared to the W unit. As the subsurface DS exceeded 20 % during the dry season, the population increased. The WP unit showed a 43% higher above-ground plant biomass compared to the P unit. In WB analysis, evapotranspiration (ET) was 46% higher in the WP unit (average daily ET = 5.44 mm in the dry season). The main process of water loss was through drainage and Awhile water content in RS layer was 57 % during feeding period. The water percolation rate of all units decreased by 99%, particularly during the wet season, reaching less than 0.1 m.day-1.
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Aguas del Alcantarillado , Humedales , Poaceae , Plantas , Agua , Eliminación de Residuos Líquidos/métodosRESUMEN
CASZ1 is a conserved transcription factor involved in neural development, blood vessel assembly and heart morphogenesis. CASZ1 has been implicated in cancer, either suppressing or promoting tumor development depending on the tissue. However, the impact of CASZ1 on hematological tumors remains unknown. Here, we show that the T-cell oncogenic transcription factor TAL1 is a direct positive regulator of CASZ1, that T-cell acute lymphoblastic leukemia (T-ALL) samples at diagnosis overexpress CASZ1b isoform, and that CASZ1b expression in patient samples correlates with PI3KAKT- mTOR signaling pathway activation. In agreement, overexpression of CASZ1b in both Ba/F3 and T-ALL cells leads to the activation of PI3K signaling pathway, which is required for CASZ1b-mediated transformation of Ba/F3 cells in vitro and malignant expansion in vivo. We further demonstrate that CASZ1b cooperates with activated NOTCH1 to promote T-ALL development in zebrafish, and that CASZ1b protects human T-ALL cells from serum deprivation and treatment with chemotherapeutic drugs. Taken together, our studies indicate that CASZ1b is a TAL1-regulated gene that promotes T-ALL development and resistance to chemotherapy.
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The environmental impact of biowaste generated during animal production can be mitigated by applying a circular economy model: recycling, reinventing the life cycle of biowaste, and developing it for a new use. The aim of this study was to evaluate the effect of adding sugar concentrate solutions obtained from the nanofiltration of fruit biowaste (mango peel) to slurry from piglets fed with diets incorporating macroalgae on biogas production performance. The nanofiltration of ultrafiltration permeates from aqueous extracts of mango peel was carried out using membranes with a molecular weight cut-off of 130 Da until a volume concentration factor of 2.0 was reached. A slurry resulting from piglets fed with an alternative diet with the incorporation of 10% Laminaria was used as a substrate. Three different trials were performed sequentially: (i) a control trial (AD0) with faeces resulting from a cereal and soybean-meal-based diet (S0); (ii) a trial with S1 (10% L. digitata) (AD1), and (iii) an AcoD trial to assess the effect of the addition of a co-substrate (20%) to S1 (80%). The trials were performed in a continuous-stirred tank reactor (CSTR) under mesophilic conditions (37.0 ± 0.4 °C), with a hydraulic retention time (HRT) of 13 days. The specific methane production (SMP) increased by 29% during the anaerobic co-digestion process. These results can support the design of alternative valorisation routes for these biowastes, contributing to sustainable development goals.
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Sludge Treatment Reed Beds (STRBs) have been used worldwide over the past few decades. This review aims to overarchingly identify and appraise the currently available knowledge of STRB technology and discern climatic patterns through Meta-Analysis (MA). We systematically searched Google Scholar, Scopus, and Web of Science databases (up to Dec 2021) via a combination of keywords to identify English-language studies published in peer-reviewed journals. Of 142 potential articles, 73 studies met the present review objectives and inclusion criteria. Four STRB classifications including typical STRB, earthworm STRB, Sludge Treatment Electro Wetland (STEW), and earthworm STEW were found since 1990. The data and information on STRBs' configuration, operational parameters in terms of location, type of sewage sludge, study scale, Sludge Loading Rate (SLR), Dry Solid (DS), the proportion of Volatile Solid to DS (VS/DS), and their association with the feeding and resting modes were extracted from the selected articles. The analysis was focused on the interconnections between operational parameters and system efficiency for Temperate type 1 (low intensity of solar radiation), Temperate type 2 (high intensity of solar radiation), and Tropical climates. Based on MA, we found the average SLRs of 50, 70, and 101 Kg.DM.m-2.year-1 for Temperate type 1, Temperate type 2, and Tropical climates respectively, and DS during the feeding of 33 %, 35 %, and 40 %. A qualitative comparison of Arid and Polar climates was also performed given the reduced number of studies available in these climates. The volume of the sludge reduced was 60 % higher and the height of accumulated sludge was annually 2 cm in the earthworm STRBs, and STEWs compared to typical STRBs, which was 6 cm annually in Tropical climates. Correlation analysis, media characterization, list of plant species, and the removal efficiency of STRBs in the residual sludge and leachate are mentioned as well.
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Oligoquetos , Aguas del Alcantarillado , Animales , Metaanálisis como Asunto , Aguas del Alcantarillado/análisis , Eliminación de Residuos Líquidos , HumedalesRESUMEN
In this study, co-digestion of mixed sewage sludge from a wastewater treatment plant (WWTP) and partially dephenolised two-phase olive pomace (DOP) as a co-substrate was addressed with the aim of improving the biodigestibility of both substrates. The introduction of DOP into WWTP anaerobic digester facilities could significantly increase biomethane production and enhance the sustainability of both activities. An improvement in the system's performance was supported by stability parameters: total alkalinity increased and stabilised with the addition of 5% v/v DOP, and the specific energy loading rate was maintained at 0.177 ± 0.03 d-1, which indicated better buffer capacity and stability in the bioreactor, and the possibility of enhancing the organic loading rate. In terms of average daily biogas production rate, an increase of 39% was achieved, up to 0.39 ± 0.11 L L-1d-1. Moreover, there was a 40% and 37% improvement in specific methane production and methane production rate, respectively, up to 0.28 ± 0.02 L CH4 g TVS-1 and 0.26 ± 0.08 L L-1d-1. In addition, the proposed strategy leads to an energy saving of 20,328.6 kWh year-1 at the WWTP as a result of the electric energy production surplus, corresponding to an annual saving of 3293.23.
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Olea , Aguas del Alcantarillado , Anaerobiosis , Biocombustibles/análisis , Reactores Biológicos , Digestión , MetanoRESUMEN
Interleukin-7 receptor α (encoded by IL7R) is essential for lymphoid development. Whether acute lymphoblastic leukemia (ALL)-related IL7R gain-of-function mutations can trigger leukemogenesis remains unclear. Here, we demonstrate that lymphoid-restricted mutant IL7R, expressed at physiological levels in conditional knock-in mice, establishes a pre-leukemic stage in which B-cell precursors display self-renewal ability, initiating leukemia resembling PAX5 P80R or Ph-like human B-ALL. Full transformation associates with transcriptional upregulation of oncogenes such as Myc or Bcl2, downregulation of tumor suppressors such as Ikzf1 or Arid2, and major IL-7R signaling upregulation (involving JAK/STAT5 and PI3K/mTOR), required for leukemia cell viability. Accordingly, maximal signaling drives full penetrance and early leukemia onset in homozygous IL7R mutant animals. Notably, we identify 2 transcriptional subgroups in mouse and human Ph-like ALL, and show that dactolisib and sphingosine-kinase inhibitors are potential treatment avenues for IL-7R-related cases. Our model, a resource to explore the pathophysiology and therapeutic vulnerabilities of B-ALL, demonstrates that IL7R can initiate this malignancy.
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Subunidad alfa del Receptor de Interleucina-7/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Animales , Antineoplásicos/farmacología , Línea Celular Tumoral , Supervivencia Celular/genética , Mutación con Ganancia de Función , Heterocigoto , Homocigoto , Humanos , Subunidad alfa del Receptor de Interleucina-7/metabolismo , Ratones , Penetrancia , Lesiones Precancerosas/genética , Lesiones Precancerosas/patología , Leucemia-Linfoma Linfoblástico de Células Precursoras B/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patología , Células Precursoras de Linfocitos B/patología , Proteínas Proto-Oncogénicas p21(ras)/genética , Transducción de Señal/efectos de los fármacosRESUMEN
Few therapies are currently available for patients with KRAS-driven cancers, highlighting the need to identify new molecular targets that modulate central downstream effector pathways. Here we found that the microRNA (miRNA) cluster including miR181ab1 is a key modulator of KRAS-driven oncogenesis. Ablation of Mir181ab1 in genetically engineered mouse models of Kras-driven lung and pancreatic cancer was deleterious to tumor initiation and progression. Expression of both resident miRNAs in the Mir181ab1 cluster, miR181a1 and miR181b1, was necessary to rescue the Mir181ab1-loss phenotype, underscoring their nonredundant role. In human cancer cells, depletion of miR181ab1 impaired proliferation and 3D growth, whereas overexpression provided a proliferative advantage. Lastly, we unveiled miR181ab1-regulated genes responsible for this phenotype. These studies identified what we believe to be a previously unknown role for miR181ab1 as a potential therapeutic target in 2 highly aggressive and difficult to treat KRAS-mutated cancers.
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Carcinogénesis/metabolismo , Neoplasias Pulmonares/metabolismo , MicroARNs/metabolismo , Familia de Multigenes , Neoplasias Experimentales/metabolismo , Neoplasias Pancreáticas/metabolismo , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , ARN Neoplásico/metabolismo , Animales , Carcinogénesis/genética , Línea Celular Tumoral , Proliferación Celular , Humanos , Neoplasias Pulmonares/genética , Ratones , Ratones Noqueados , MicroARNs/genética , Neoplasias Experimentales/genética , Neoplasias Pancreáticas/genética , Proteínas Proto-Oncogénicas p21(ras)/genética , ARN Neoplásico/genéticaRESUMEN
T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological malignancy with a dismal prognosis in patients with resistant or relapsed disease. Although NOTCH is a known driver in T-ALL, its clinical inhibition has significant limitations. Our previous studies suggested that NRARP, a negative regulator of Notch signaling, could have a suppressive role in T-ALL. Here, we report that NRARP levels are significantly increased in primary T-ALL cells suggesting that NRARP is not sufficient to block NOTCH oncogenic signals. Interestingly, although NRARP overexpression blocks NOTCH1 signaling and delays the proliferation of T-ALL cells that display high levels of Notch1 signaling, it promotes the expansion of T-ALL cells with lower levels of Notch1 activity. We found that NRARP interacts with lymphoid enhancer-binding factor 1 (LEF1) and potentiates Wnt signaling in T-ALL cells with low levels of Notch. Together these results indicate that NRARP plays a dual role in T-ALL pathogenesis, regulating both Notch and Wnt pathways, with opposite functional effects depending on Notch activity. Consistent with this hypothesis, mice transplanted with T-cells co-expressing NOTCH1 and NRARP develop leukemia later than mice transplanted with T-NOTCH1 cells. Importantly, mice transplanted with T-cells overexpressing NRARP alone developed leukemia with similar kinetics to those transplanted with T-NOTCH1 cells. Our findings uncover a role for NRARP in T-ALL pathogenesis and indicate that Notch inhibition may be detrimental for patients with low levels of Notch signaling, which would likely benefit from the use of Wnt signaling inhibitors. Importantly, our findings may extend to other cancers where Notch and Wnt play a role.
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Péptidos y Proteínas de Señalización Intracelular/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patología , Receptores Notch/metabolismo , Vía de Señalización Wnt , Línea Celular Tumoral , Humanos , Regulación hacia ArribaRESUMEN
Phosphate (P) recovery from urban wastewaters is an effective strategy to address environmental protection and resource conservation, aiming at an effective circular economy. Off-grid wastewater treatment systems like urine-diverting toilets (UDT) can contribute to source separation towards nutrient recovery, namely phosphorus recovery. Effectiveness of P precipitation requires a process-based knowledge regarding pH, Mg:PO4, contact time and their interactions in P recovery and crystal morphology. Several studies failed to see the process as a whole and how factors influence both morphology and P recovery for UDT hydrolysed urine. This study addressed the above-mentioned factors and their interactions, and results showed that pH and Mg:PO4 ratio are the key factors for struvite precipitation, whereas contact time is relevant for crystal growth. The recommended set of factors proposed (pH 8.5, Mg:PO4 ratio of 1.2:1 and 30 minutes contact time) not only promotes a high precipitation yield - 99% of P with co-precipitation of at least 21% of ammonium (NH4 +) - but also leads to larger crystals with lower water solubility (10% less crystals dissolved in water after 3 days). The obtained outcome facilitates the downstream process and leads to a more efficient slow-release fertiliser, as less P is wasted to receiving waters by leaching, minimising eutrophication processes.
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Aparatos Sanitarios , Fosfatos , Precipitación Química , Concentración de Iones de Hidrógeno , Compuestos de Magnesio , Fósforo , Estruvita , Eliminación de Residuos LíquidosRESUMEN
T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological cancer for which treatment options often result in incomplete therapeutic efficacy and long-term side-effects. Interleukin 7 (IL-7) and its receptor IL-7Rα promote T-ALL development and mutational activation of IL-7Rα associates with very high risk in relapsed disease. Using combinatorial phage-display libraries and antibody reformatting, we generated a fully human IgG1 monoclonal antibody (named B12) against both wild-type and mutant human IL-7Rα, predicted to form a stable complex with IL-7Rα at a different site from IL-7. B12 impairs IL-7/IL-7R-mediated signaling, sensitizes T-ALL cells to treatment with dexamethasone and can induce cell death per se. The antibody also promotes antibody-dependent natural killer-mediated leukemia cytotoxicity in vitro and delays T-cell leukemia development in vivo, reducing tumor burden and promoting mouse survival. B12 is rapidly internalized and traffics to the lysosome, rendering it an attractive vehicle for targeted intracellular delivery of cytotoxic cargo. Consequently, we engineered a B12-MMAE antibody-drug conjugate and provide proof-of-concept evidence that it has increased leukemia cell killing abilities as compared with the naked antibody. Our studies serve as a stepping stone for the development of novel targeted therapies in T-ALL and other diseases where IL-7Rα has a pathological role.
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Anticuerpos Monoclonales/farmacología , Antineoplásicos/farmacología , Leucemia-Linfoma Linfoblástico de Células T Precursoras/economía , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Receptores de Interleucina-7/metabolismo , Animales , Línea Celular , Humanos , Inmunoglobulina G/metabolismo , Interleucina-7/metabolismo , Ratones , Transducción de Señal/efectos de los fármacos , Linfocitos T/efectos de los fármacos , Linfocitos T/metabolismoRESUMEN
Despite remarkable progress in polychemotherapy protocols, pediatric B-cell acute lymphoblastic leukemia (B-ALL) remains fatal in around 20% of cases. Hence, novel targeted therapies are needed for patients with poor prognosis. Glucocorticoids (GCs) are drugs commonly administrated for B-ALL treatment. Activation of the phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin signaling pathway is frequently observed in B-ALL and contributes to GC-resistance. Here, we analyzed for the first time to our knowledge, the therapeutic potential of pan and isoform-selective PI3K p110 inhibitors, alone or combined with dexamethasone (DEX), in B-ALL leukemia cell lines and patient samples. We found that a pan PI3K p110 inhibitor displayed the most powerful cytotoxic effects in B-ALL cells, by inducing cell cycle arrest and apoptosis. Both a pan PI3K p110 inhibitor and a dual γ/δ PI3K p110 inhibitor sensitized B-ALL cells to DEX by restoring nuclear translocation of the GC receptor and counteracted stroma-induced DEX-resistance. Finally, gene expression analysis documented that, on one hand the combination consisting of a pan PI3K p110 inhibitor and DEX strengthened the DEX-induced up- or down-regulation of several genes involved in apoptosis, while on the other, it rescued the effects of genes that might be involved in GC-resistance. Overall, our findings strongly suggest that PI3K p110 inhibition could be a promising strategy for treating B-ALL patients by improving GC therapeutic effects and/or overcoming GC-resistance.
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Antineoplásicos/farmacología , Fosfatidilinositol 3-Quinasa Clase I/antagonistas & inhibidores , Dexametasona/farmacología , Glucocorticoides/farmacología , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Apoptosis/efectos de los fármacos , Linfocitos B/metabolismo , Puntos de Control del Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Niño , Preescolar , Compuestos Heterocíclicos con 3 Anillos/farmacología , Humanos , Isoquinolinas/farmacología , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Purinas/farmacología , Quinazolinonas/farmacología , Quinoxalinas/farmacología , Tiazolidinedionas/farmacología , Triazinas/farmacologíaRESUMEN
T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological cancer that arises from clonal expansion of transformed T-cell precursors. In this review we summarize the current knowledge on the external stimuli and cell-intrinsic lesions that drive aberrant activation of pivotal, pro-tumoral intracellular signaling pathways in T-cell precursors, driving transformation, leukemia expansion, spread or resistance to therapy. In addition to their pathophysiological relevance, receptors and kinases involved in signal transduction are often attractive candidates for targeted drug development. As such, we discuss also the potential of T-ALL signaling players as targets for therapeutic intervention.
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Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Transducción de Señal , Animales , Humanos , Modelos BiológicosRESUMEN
Previous results indicated that miR-146b-5p is downregulated by TAL1, a transcription factor critical for early hematopoiesis that is frequently overexpressed in T-cell acute lymphoblastic leukemia (T-ALL) where it has an oncogenic role. Here, we confirmed that miR-146b-5p expression is lower in TAL1-positive patient samples than in other T-ALL cases. Furthermore, leukemia T-cells display decreased levels of miR-146b-5p as compared to normal T-cells, thymocytes and other hematopoietic progenitors. MiR-146b-5p silencing enhances the in vitro migration and invasion of T-ALL cells, associated with increased levels of filamentous actin and chemokinesis. In vivo, miR-146b overexpression in a TAL1-positive cell line extends mouse survival in a xenotransplant model of human T-ALL. In contrast, knockdown of miR-146b-5p results in leukemia acceleration and decreased mouse overall survival, paralleled by faster tumor infiltration of the central nervous system. Our results suggest that miR-146b-5p is a functionally relevant microRNA gene in the context of T-ALL, whose negative regulation by TAL1 and possibly other oncogenes contributes to disease progression by modulating leukemia cell motility and disease aggressiveness.
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Movimiento Celular/genética , Regulación Leucémica de la Expresión Génica , MicroARNs/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Animales , Línea Celular Tumoral , Progresión de la Enfermedad , Femenino , Técnicas de Silenciamiento del Gen , Humanos , Estimación de Kaplan-Meier , Masculino , Ratones Endogámicos NOD , Ratones SCID , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patología , Proteína 1 de la Leucemia Linfocítica T Aguda/genética , Ensayos Antitumor por Modelo de Xenoinjerto/métodosRESUMEN
Phosphorylation regulates the conformation, stability, homo- and heterotypic protein interactions, localization, and activity of the tumor suppressor PTEN. From a simple picture, at the beginning of this millennium, recognizing that CK2 phosphorylated PTEN at the C-terminus and thereby impacted on PTEN stability and activity, research has led to a significantly more complex scenario today, where for instance GSK3, Plk3, ATM, ROCK or Src-family kinases are also gaining the spotlight in this evolving play. Here, we review the current knowledge on the kinases that phosphorylate PTEN, and on the impact that specific phosphorylation events have on PTEN function.
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Fosfohidrolasa PTEN/fisiología , Proteínas Quinasas/fisiología , Proteínas Supresoras de Tumor/fisiología , Secuencia de Aminoácidos , Animales , Humanos , Datos de Secuencia Molecular , Fosforilación/fisiologíaRESUMEN
Leukemia stem cells (LSCs) are considered responsible for leukemia initiation, relapse and resistance to chemotherapy. These cells have self-renewal capacity and originate the other cells in the leukemia pool. Therefore, in order to completely eradicate leukemia cells and consequently cure the disease, therapies should in principle necessarily target LSCs. However, the fact that LSCs share functional and phenotypic properties with normal hematopoietic stem cells (HSCs) poses a significant challenge: how to target LSCs without damaging normal HSCs and compromising hematopoiesis? The discovery that PTEN regulates LSCs and HSCs through different mechanisms, demonstrated that it is possible to identify pathways that differentially impact leukemia and normal stem cell function and opened new therapeutic perspectives for the selective elimination of LSCs. In this review, we briefly discuss the mechanisms that regulate PTEN function in LSCs and HSCs and their potential for the development of LSC-targeted therapies.
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Leucemia/enzimología , Células Madre Neoplásicas/enzimología , Fosfohidrolasa PTEN/metabolismo , Animales , Células Madre Hematopoyéticas/enzimología , Humanos , Leucemia/genética , Fosfohidrolasa PTEN/genética , Transducción de SeñalRESUMEN
Much has been learned about the molecular and cellular components critical for the control of immune responses and tolerance. It remains a challenge, however, to control the immune response and tolerance at the system level without causing significant toxicity to normal tissues. Recent studies suggest that microRNA (miRNA) genes, an abundant class of non-coding RNA genes that produce characteristic approximately 22 nucleotides small RNAs, play important roles in immune cells. In this article, we discuss emerging knowledge regarding the functions of miRNA genes in the immune system. We delve into the roles of miRNAs in regulating signaling strength and threshold, homeostasis, and the dynamics of the immune response and tolerance during normal and pathogenic immunological conditions. We also present observations based on analyzes of miR-181 family genes that indicate the potential functions of primary and/or precursor miRNAs in target recognition and explore the impact of these findings on target identification. Finally, we illustrate that despite the subtle effects of miRNAs on gene expression, miRNAs have the potential to influence the outcomes of normal and pathogenic immune responses by controlling the quantitative and dynamic aspects of immune responses. Tuning miRNA functions in immune cells, through gain- and loss-of-function approaches in mice, may reveal novel approach to restore immune equilibrium from pathogenic conditions, such as autoimmune disease and leukemia, without significant toxicity.
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Tolerancia Inmunológica , Inmunidad , Inmunomodulación , MicroARNs/inmunología , Animales , Homeostasis/genética , Homeostasis/inmunología , Humanos , Tolerancia Inmunológica/genética , Inmunidad/genética , Ratones , Transducción de Señal/genética , Transducción de Señal/inmunologíaRESUMEN
Oncogenes, which are essential for tumor initiation, development, and maintenance, are valuable targets for cancer therapy. However, it remains a challenge to effectively inhibit oncogene activity by targeting their downstream pathways without causing significant toxicity to normal tissues. Here we show that deletion of mir-181a-1/b-1 expression inhibits the development of Notch1 oncogene-induced T cell acute lymphoblastic leukemia (T-ALL). mir-181a-1/b-1 controls the strength and threshold of Notch activity in tumorigenesis in part by dampening multiple negative feedback regulators downstream of NOTCH and pre-T cell receptor (TCR) signaling pathways. Importantly, although Notch oncogenes utilize normal thymic progenitor cell genetic programs for tumor transformation, comparative analyses of mir-181a-1/b-1 function in normal thymocyte and tumor development demonstrate that mir-181a-1/b-1 can be specifically targeted to inhibit tumor development with little toxicity to normal development. Finally, we demonstrate that mir-181a-1/b-1, but not mir-181a-2b-2 and mir-181-c/d, controls the development of normal thymic T cells and leukemia cells. Together, these results illustrate that NOTCH oncogene activity in tumor development can be selectively inhibited by targeting the molecular networks controlled by mir-181a-1/b-1.