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Non-small cell lung cancer (NSCLC) patients are often elderly or unfit and thus cannot tolerate standard aggressive therapy regimes. In our study, we test the efficacy of the DNA-hypomethylating agent decitabine (DAC) in combination with all-trans retinoic acid (ATRA), which has been shown to possess little systemic adverse effects. Screening a broad panel of 56 NSCLC cell lines uncovered a decrease in cell viability after the combination treatment in 77% of the cell lines. Transcriptomics, proteomics, proliferation and migration profiling revealed that fast proliferating and slowly migrating cell lines were more sensitive to the drug combination. The comparison of mutational profiles found oncogenic KRAS mutations only in sensitive cells. Additionally, different cell lines showed a heterogeneous gene expression response to the treatment pointing to diverse mechanisms of action. Silencing KRAS, RIG-I or RARB partially reversed the sensitivity of KRAS-mutant NCI-H460 cells. To study resistance, we generated two NCI-H460 cell populations resistant to ATRA and DAC, which migrated faster and proliferated slower than the parental sensitive cells and showed signs of senescence. In summary, this comprehensive dataset uncovers a broad sensitivity of NSCLC cells to the combinatorial treatment with DAC and ATRA and indicates that migration and proliferation capacities correlate with and could thus serve as determinants for drug sensitivity in NSCLC.
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Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Humanos , Anciano , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Tretinoina/farmacología , Tretinoina/uso terapéutico , Decitabina/farmacología , Decitabina/uso terapéutico , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Proteínas Proto-Oncogénicas p21(ras)/genética , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Línea Celular Tumoral , Proliferación CelularRESUMEN
The reconstruction and modification of metal surfaces upon O_{2} adsorption plays an important role in oxidation processes and in gauging their catalytic activity. Here, we show by employing scanning tunneling microscopy and the ab initio density functional theory that Ag atoms are extracted from pristine (110) terraces upon O_{2} dissociation, resulting in vacancies and in Ag-O complexes. The substrate roughening generates undercoordinated atoms and opens pathways to the Ag subsurface layer. With increasing O coverage, multiple vacancies give rise to remarkable structures. The mechanism is expected to be very general depending on the delicate interplay of energy and entropy, so that it may be active for other materials at different temperatures.
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The ability to engineer nearly perfect ultrathin oxide layers, up to the limit of monolayer thickness, is a key issue for nanotechnological applications. Here we face the difficult and important case of ultrathin MgO films on Ag(100), for which no extended and well-ordered layers could thus far be produced in the monolayer limit. We demonstrate that their final morphology depends not only on the usual growth parameters (crystal temperature, metal flux, and oxygen partial pressure), but also on aftergrowth treatments controlling so far neglected thermodynamics constraints. We thus succeed in tuning the shape of the oxide films from irregular, nanometer-sized, monolayer-thick islands to slightly larger, perfectly squared, bilayer islands, to extended monolayers limited apparently only by substrate steps.
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Óxido de Magnesio/química , Nanoestructuras/química , Nanotecnología/métodos , Plata/química , Microscopía de Túnel de Rastreo/métodos , Temperatura , TermodinámicaRESUMEN
Nonstop extension mutations, a.k.a. stop-lost or stop-loss mutations, convert a stop codon into a sense codon resulting in translation into the 3' untranslated region until the next in-frame stop codon, thereby extending the C-terminus of a protein. In cancer, only nonstop mutations in SMAD4 have been functionally characterized, while the impact of other nonstop mutations remain unknown. Here, we exploit our pan-cancer NonStopDB dataset and test all 2335 C-terminal extensions arising from somatic nonstop mutations in cancer for their impact on protein expression. In a high-throughput screen, 56.1% of the extensions effectively reduce protein abundance. Extensions of multiple tumor suppressor genes like PTEN, APC, B2M, CASP8, CDKN1B and MLH1 are effective and validated for their suppressive impact. Importantly, the effective extensions possess a higher hydrophobicity than the neutral extensions linking C-terminal hydrophobicity with protein destabilization. Analyzing the proteomes of eleven different species reveals conserved patterns of amino acid distribution in the C-terminal regions of all proteins compared to the proteomes like an enrichment of lysine and arginine and a depletion of glycine, leucine, valine and isoleucine across species and kingdoms. These evolutionary selection patterns are disrupted in the cancer-derived effective nonstop extensions.
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Interacciones Hidrofóbicas e Hidrofílicas , Mutación , Neoplasias , Humanos , Neoplasias/genética , Neoplasias/metabolismo , Aminoácidos/metabolismo , Aminoácidos/genética , Aminoácidos/química , Proteína Smad4/genética , Proteína Smad4/metabolismo , Proteína Smad4/química , Homólogo 1 de la Proteína MutL/genética , Homólogo 1 de la Proteína MutL/metabolismo , Homólogo 1 de la Proteína MutL/química , Fosfohidrolasa PTEN/genética , Fosfohidrolasa PTEN/metabolismo , Fosfohidrolasa PTEN/química , Evolución Molecular , Codón de Terminación/genética , Proteína de la Poliposis Adenomatosa del Colon/genética , Proteína de la Poliposis Adenomatosa del Colon/metabolismo , Proteína de la Poliposis Adenomatosa del Colon/química , Animales , Proteoma/metabolismo , Genes Supresores de Tumor , Secuencia ConservadaRESUMEN
COVID-19 has impacted mankind drastically; whether it be physical and mental health, global economy, or social disruption, everyone has sustained losses. To prevent the spread, strict containment measures and stay at home guidelines were issued by officials. Due to this, an unanticipated and rapid change has occurred in the daily routine and lifestyle of the people. Physical distancing and quarantine measures strongly impacted people's lives, their eating habits and everyday ablutions. A comprehensive search of recent literature related to nutrition and diet during the pandemic was undertaken using electronic databases like MEDLINE, PubMed, Google Scholar, and ResearchGate. This review deals with the effects of COVID-19 on malnutrition, the foods that help in boosting the immune system, and on specific, vulnerable, age groups. Although there are various health concerns that has come up during the pandemic, through this review, we investigate some aspects related to nutrition as the recovery of every individual who was affected by COVID-19 was influenced by their nutritional intake.
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Background: Noise in intensive care units (ICUs) has always been a problem, but noise above the recommended range affects not only the patient but staff as well. It is clear that some noise in the ICU is inevitable, but exceeding the normal range brings various physiologic and psychologic changes, which directly affect health. This review presents a synthesis of noise sources in the ICU and the potential interventions designed to attenuate noise and protect patients. Materials and Methods: An extensive literature search, using electronic databases such as MEDLINE, PubMed, Google Scholar, and Research gate to understand the noise in ICU, effects of noise, and noise reduction interventions were undertaken. Results: Findings were such as noise enhances the release of cortisol, increases oxygen consumption, increases sleep disturbances, increases the need for analgesia and sedation, and disrupts circadian rhythm. Many studies reported that measurement was always higher despite implementing noise reduction interventions. Conclusions: ICU survivors always recall their memories, and for them, ICU admission becomes a negative experience for life. However, the sustainability of any single intervention did not show awe-inspiring results, whereas a bundle kind of interventions did show some effects. However, high-quality evidence demonstrating the benefit of any intervention on patient outcomes is still lacking.
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Cuidadores , Ruido , Humanos , Hidrocortisona , Unidades de Cuidados Intensivos , Salud Mental , Ruido/efectos adversosRESUMEN
Cell migration is an essential process in health and in disease, including cancer metastasis. A comprehensive inventory of migration factors is nonetheless lacking-in part due to the difficulty in assessing migration using high-throughput technologies. Hence, there are currently very few screens that systematically reveal factors controlling cell migration. Here, we introduce MigExpress as a platform for the 'identification of Migration control genes by differential Expression'. MigExpress exploits the combination of in-depth molecular profiling and the robust quantitative analysis of migration capacity in a broad panel of samples and identifies migration-associated genes by their differential expression in slow- versus fast-migrating cells. We applied MigExpress to investigate non-small cell lung cancer (NSCLC), which is the most frequent cause of cancer mortality mainly due to metastasis. In 54 NSCLC cell lines, we comprehensively determined mRNA and protein expression. Correlating the transcriptome and proteome profiles with the quantified migration properties led to the discovery and validation of FLNC, DSE, CPA4, TUBB6, and BICC1 as migration control factors in NSCLC cells, which were also negatively correlated with patient survival. Notably, FLNC was the least expressed filamin in NSCLC, but the only one controlling cell migration and correlating with patient survival and metastatic disease stage. In our study, we present MigExpress as a new method for the systematic analysis of migration factors and provide a comprehensive resource of transcriptomic and proteomic data of NSCLC cell lines related to cell migration.
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Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Carcinoma de Pulmón de Células no Pequeñas/patología , Línea Celular Tumoral , Movimiento Celular/genética , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias Pulmonares/patología , Proteómica/métodosRESUMEN
BACKGROUND: Gliomas are the most common and lethal type of intracranial tumors. With the current treatment regime, the median survival of patients with grade IV glioma (glioblastoma/GBM) remains at 14-16 months. RNA editing modifies the function and regulation of transcripts. The development of glial tumors may be caused by altered RNA editing events. METHODS: In this study, we uncover the global RNA editome landscape of glioma patients from RNA-seq data of control, lower grade glioma (LGG) and GBM samples (n = 1,083). RESULTS: A-to-I editing events were found to comprise 80% of the total editing events of which 96% were located in the Alu regions. The total RNA editing events were found to be reduced in glioma compared to control samples. More specifically, we found Gamma-aminobutyric acid type A receptor alpha3 (GABRA3) to be edited (c.1026 A-to-G; pI343M) in 73% (editing ratio 0.8) of control samples compared to LGG (28.96%; 0.47) and GBM (5.2%; 0.53) samples. GABRA3 transcript level was found to be downregulated in glioma compared to control in a grade-specific manner with GBMs having the lowest level of the transcript. Further, GABRA3 transcripts were observed to be higher in edited compared to unedited glioma samples. The transcript and protein levels of exogenously expressed gene were found to be higher for edited compared to unedited GABRA3 in glioma cells. Further, exogenously expressed edited GABRA3 inhibited migration and invasion of glioma cells efficiently but not the unedited GABRA3. CONCLUSION: Collectively, our study discovered a reduction in RNA editing during glioma development. We further demonstrate that elevated RNA editing maintains a high level of GABRA3 RNA and protein in normal glial cells which provides a less migratory environment for the normal functioning of the brain. In contrast, the reduction in GABRA3 protein levels, due to lower stability of unedited RNA, results in the loss of function which confers an aggressive phenotype to GBM tumor.
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Purpose: Despite significant advances in the understanding of the biology, the prognosis of glioblastoma (GBM) remains dismal. The objective was to carry out whole-exome sequencing (WES) of Indian glioma and integrate with that of TCGA to find clinically relevant mutated pathways.Experimental Design: WES of different astrocytoma samples (n = 42; Indian cohort) was carried out and compared with that of TCGA cohort. An integrated analysis of mutated genes from Indian and TCGA cohorts was carried out to identify survival association of pathways with genetic alterations. Patient-derived glioma stem-like cells, glioma cell lines, and mouse xenograft models were used for functional characterization of calcitonin receptor (CALCR) and establish it as a therapeutic target.Results: A similar mutation spectrum between the Indian cohort and TCGA cohort was demonstrated. An integrated analysis identified GBMs with defective "neuroactive ligand-receptor interaction" pathway (n = 23; 9.54%) that have significantly poor prognosis (P < 0.0001). Furthermore, GBMs with mutated calcitonin receptor (CALCR) or reduced transcript levels predicted poor prognosis. Exogenously added calcitonin (CT) inhibited various properties of glioma cells and pro-oncogenic signaling pathways in a CALCR-dependent manner. Patient-derived mutations in CALCR abolished these functions with the degree of loss of function negatively correlating with patient survival. WT CALCR, but not the mutant versions, inhibited Ras-mediated transformation of immortalized astrocytes in vitro Furthermore, calcitonin inhibited patient-derived neurosphere growth and in vivo glioma tumor growth in a mouse model.Conclusions: We demonstrate CT-CALCR signaling axis is an important tumor suppressor pathway in glioma and establish CALCR as a novel therapeutic target for GBM. Clin Cancer Res; 24(6); 1448-58. ©2017 AACR.
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Neoplasias Encefálicas/genética , Neoplasias Encefálicas/mortalidad , Glioblastoma/genética , Glioblastoma/mortalidad , Mutación con Pérdida de Función , Receptores de Calcitonina/genética , Neoplasias Encefálicas/patología , Línea Celular Tumoral , Proliferación Celular , Progresión de la Enfermedad , Exoma , Regulación Neoplásica de la Expresión Génica , Glioblastoma/patología , Humanos , Evaluación del Resultado de la Atención al Paciente , Pronóstico , Receptores de Calcitonina/metabolismo , Transducción de SeñalRESUMEN
The most common and aggressive form of primary brain tumor in adults is glioblastoma (GBM). From the global DNA methylation profiling study, previously published from our laboratory, we identified Guanine Nucleotide binding-protein Gamma subunit 4 (GNG4) to be one of the most hyper methylated and down regulated genes in GBM. GBM derived cell lines showed reduced GNG4 transcript levels, which could be reversed by methylation inhibitor treatment. Bisulphite sequencing confirmed the methylation status in glioblastoma tumor tissue and GBM derived cell lines. Overexpression of GNG4 was found to inhibit proliferation and colony formation of GBM cell lines and in vitro transformation of immortalized human astrocytes, thus suggesting a potential tumor suppressor role of GNG4 in GBM. Correlation of GNG4 transcript levels with that of all GPCRs from TCGA data revealed chemokine receptors as the potential target of GNG4. Furthermore, exogenous over expression of GNG4 inhibited SDF1α/CXCR4-dependent chemokine signaling as seen by reduced pERK and pJNK and GBM cell migration. The inhibitory association between GNG4 and SDF1α/CXCR4 was more evident in mesenchymal subtype of GBM. Thus, this study identifies GNG4 as an inhibitor of SDF1α/CXCR4-dependent signaling and emphasizes the significance of epigenetic inactivation of GNG4 in glioblastoma, especially in mesenchymal subtype.
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Cell lines derived from tumor tissues have been used as a valuable system to study gene regulation and cancer development. Comprehensive characterization of the genetic background of cell lines could provide clues on novel genes responsible for carcinogenesis and help in choosing cell lines for particular studies. Here, we have carried out whole exome and RNA sequencing of commonly used glioblastoma (GBM) cell lines (U87, T98G, LN229, U343, U373 and LN18) to unearth single nucleotide variations (SNVs), indels, differential gene expression, gene fusions and RNA editing events. We obtained an average of 41,071 SNVs out of which 1,594 (3.88%) were potentially cancer-specific. The cell lines showed frequent SNVs and indels in some of the genes that are known to be altered in GBM- EGFR, TP53, PTEN, SPTA1 and NF1. Chromatin modifying genes- ATRX, MLL3, MLL4, SETD2 and SRCAP also showed alterations. While no cell line carried IDH1 mutations, five cell lines showed hTERT promoter activating mutations with a concomitant increase in hTERT transcript levels. Five significant gene fusions were found of which NUP93-CYB5B was validated. An average of 18,949 RNA editing events was also obtained. Thus we have generated a comprehensive catalogue of genetic alterations for six GBM cell lines.
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Neoplasias Encefálicas/genética , Exoma/genética , Glioblastoma/genética , Secuencia de Aminoácidos , Secuencia de Bases , Línea Celular Tumoral , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Polimorfismo de Nucleótido Simple , Análisis de Secuencia de ARNRESUMEN
BACKGROUND: Pediatric glioblastoma multiforme (GBM) is rare, and there is a single study, a seminal discovery showing association of histone H3.3 and isocitrate dehydrogenase (IDH)1 mutation with a DNA methylation signature. The present study aims to validate these findings in an independent cohort of pediatric GBM, compare it with adult GBM, and evaluate the involvement of important functionally altered pathways. METHODS: Genome-wide methylation profiling of 21 pediatric GBM cases was done and compared with adult GBM data (GSE22867). We performed gene mutation analysis of IDH1 and H3 histone family 3A (H3F3A), status evaluation of glioma cytosine-phosphate-guanine island methylator phenotype (G-CIMP), and Gene Ontology analysis. Experimental evaluation of reactive oxygen species (ROS) association was also done. RESULTS: Distinct differences were noted between methylomes of pediatric and adult GBM. Pediatric GBM was characterized by 94 hypermethylated and 1206 hypomethylated cytosine-phosphate-guanine (CpG) islands, with 3 distinct clusters, having a trend to prognostic correlation. Interestingly, none of the pediatric GBM cases showed G-CIMP/IDH1 mutation. Gene Ontology analysis identified ROS association in pediatric GBM, which was experimentally validated. H3F3A mutants (36.4%; all K27M) harbored distinct methylomes and showed enrichment of processes related to neuronal development, differentiation, and cell-fate commitment. CONCLUSIONS: Our study confirms that pediatric GBM has a distinct methylome compared with that of adults. Presence of distinct clusters and an H3F3A mutation-specific methylome indicate existence of epigenetic subgroups within pediatric GBM. Absence of IDH1/G-CIMP status further indicates that findings in adult GBM cannot be simply extrapolated to pediatric GBM and that there is a strong need for identification of separate prognostic markers. A possible role of ROS in pediatric GBM pathogenesis is demonstrated for the first time and needs further evaluation.