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Background: The recurrence and mortality rates of bladder cancer are extremely high, and its diagnosis and treatment are global concerns. The mechanism of anoikis is closely related to tumor metastasis. Methods: First, we obtained all the data needed for this study from a public database through a formal operational process. The data were then analyzed by bioinformatics technology. Through the limma package, we screened and obtained 313 anoikis-related genes [false discovery rate (FDR) <0.05, |log fold change (FC) | >0.585]. Then, through univariate independent prognostic analysis, we further screened 146 genes (P<0.05) related to the prognosis of bladder cancer from 313 differential genes. These 146 prognostically relevant differential genes were used for least absolute shrinkage and selection operator (LASSO) regression for further screening to obtain model-related genes and output model formulas. Through the nomogram, we can calculate the survival rate of patients more accurately. The accuracy of the nomogram was also confirmed by calibration curves, independent prognostic analysis, receiver operating characteristic (ROC) curves, decision curve analysis (DCA) curves. We then analysed the sensitivity of immunotherapy in bladder cancer patients with different risk scores via Tumor Immune Dysfunction and Exclusion (TIDE). Results: Through bioinformatics technology and public databases, a prognostic model including 9 anoikis-related genes (KLF12, INHBB, CASP6, TGFBR3, FASN, TPM1, OGT, RAC3, ID4) was obtained. Integrating risk scores with clinical information, we obtained a nomogram that can accurately predict patient survival. By querying the immunohistochemical results of the Human Protein Atlas database, two of the nine model-related genes (FASN, RAC3) have the value of further research and are expected to become new biomarkers to assist the diagnosis and treatment of bladder cancer. Through immune-related analysis, we found that patients in the low-risk group appeared to be more suitable for immunotherapy, while drug sensitivity analysis showed that bladder cancer patients in the high-risk group were more sensitive to common chemotherapy drugs. Conclusions: In this study, a prognostic model that can accurately predict the prognosis of patients with bladder cancer was constructed. FASN and RAC3 are expected to become a new biomarker for the diagnosis and treatment of bladder cancer.
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Background: Clear cell renal cell carcinoma (ccRCC) is a heterogeneous tumor that accounts for a large proportion of kidney cancer, It is prone to recurrence and metastasis, and has a high mortality rate. Although mitophagy is important for metastasis and the recurrence of various tumors, its effect on renal clear cell carcinoma is poorly understood. Methods: Mitophagy-related genes were obtained through the GeneCards database. We normalised the data from different sources by removing the batch effect. Next, we conducted a preliminary screening of mitophagy-related genes and obtained prognosis-related genes from differentially expressed genes. We constructed a prognostic model using least absolute shrinkage and selection operator (LASSO) regression with data from The Cancer Genome Atlas (TCGA) and GSE29609 datasets and validated it internally. International Cancer Genome Consortium (ICGC) and E-MTAB-1980 cohorts also provided double external validation. In addition, we combined multi-omics and single-cell data to comprehensively analyse mitophagy-related gene model signature (MRGMS). Combined with the mitophagy-related gene model (MRGM) score, we constructed a nomogram. Finally, we performed pathway enrichment analysis using a variety of methods. Results: Multiomics and single-cell data analysis showed that the MRGMS is important for patients with ccRCC and is expected to become a new biomarker. The construction of a nomogram was conducive to accurately predicting patient survival. Conclusions: Mitophagy-related genes are important for predicting the prognosis of ccRCC and are conducive to the development of more personalised treatment plans for patients.
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Background: Clear cell renal cell carcinoma (ccRCC) is a malignant kidney tumour and its progression is associated with the renin secretion pathway, so this study aimed to develop a prognostic model based on renin secretion pathway-related genes. Methods: First, 453 renin secretion pathway-related genes were acquired [|log fold change (FC)| >1.5, false discovery rate (FDR) <0.05] from The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) databases. The data were combined and further screened for 188 genes associated with ccRCC prognosis (P<0.05) by univariate independent prognostic analysis. These genes were subjected to least absolute shrinkage and selection operator regression to identify potential prognostic genes to construct the prognostic model. The stability of the model was externally validated. Combined risk scores and clinical information were used to create nomograms to accurately reflect patient survival. The model-related genes were further mined for subsequent analysis. Results: A prognostic model of six renin secretion pathway genes (IGFBP3, PLAUR, CHKB-CPT1B, HOXA13, CDH13, and CDC20) was developed. Its reliability in predicting disease prognosis was confirmed by survival analysis, receiver operating characteristic (ROC) curve analysis and a risk curve. The nomogram and calibration curve showed good accuracy. The immune-related analyses revealed that the low-risk group would benefit more from immunotherapy. Conclusions: The prognostic model of ccRCC based on six renin secretion pathway-related genes can be used to guide the precise treatment of ccRCC patients.
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Background: Clear cell renal cell carcinoma (ccRCC) is the largest subtype of kidney tumour, with inflammatory responses characterising all stages of the tumour. Establishing the relationship between the genes related to inflammatory responses and ccRCC may help the diagnosis and treatment of patients with ccRCC. Methods: First, we obtained the data for this study from a public database. After differential analysis and Cox regression analysis, we obtained the genes for the establishment of a prognostic model for ccRCC. As we used data from multiple databases, we standardized all the data using the surrogate variable analysis (SVA) package to make the data from different sources comparable. Next, we used a least absolute shrinkage and selection operator (LASSO) regression to construct a prognostic model of genes related to inflammation. The data used for modelling and internal validation came from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) series (GSE29609) databases. ccRCC data from the International Cancer Genome Consortium (ICGC) database were used for external validation. Tumour data from the E-MTAB-1980 cohort were used for external validation. The GSE40453 and GSE53757 datasets were used to verify the differential expression of inflammation-related gene model signatures (IRGMS). The immunohistochemistry of IRGMS was queried through the Human Protein Atlas (HPA) database. After the adequate validation of the IRGM, we further explored its application by constructing nomograms, pathway enrichment analysis, immunocorrelation analysis, drug susceptibility analysis, and subtype identification. Results: The IRGM can robustly predict the prognosis of samples from patients with ccRCC from different databases. The verification results show that nomogram can accurately predict the survival rate of patients. Pathway enrichment analysis showed that patients in the high-risk (HR) group were associated with a variety of tumorigenesis biological processes. Immune-related analysis and drug susceptibility analysis suggested that patients with higher IRGM scores had more treatment options. Conclusions: The IRGMS can effectively predict the prognosis of ccRCC. Patients with higher IRGM scores may be better candidates for treatment with immune checkpoint inhibitors and have more chemotherapy options.
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BACKGROUND: Signal transduction mediated by heterotrimeric G proteins, which comprise the α, ß, and γ subunits, is one of the most important signaling pathways in rice plants. RGA1, which encodes the Gα subunit of the G protein, plays an important role in the response to various types of abiotic stress, including salt, drought, and cold stress. However, the role of RGA1 in the response to heat stress remains unclear. RESULTS: The heat-resistant mutant ett1 (enhanced thermo-tolerance 1) with a new allele of the RGA1 gene was derived from an ethane methyl sulfonate-induced Zhonghua11 mutant. After 45 °C heat stress treatment for 36 h and recovery for 7 d, the survival rate of the ett1 mutants was significantly higher than that of wild-type (WT) plants. The malondialdehyde content was lower, and the maximum fluorescence quantum yield of photosystem II, peroxidase activity, and hsp expression were higher in ett1 mutants than in WT plants after 12 h of exposure to 45 °C. The RNA-sequencing results revealed that the expression of genes involved in the metabolism of carbohydrate, nicotinamide adenine dinucleotide, and energy was up-regulated in ett1 under heat stress. The carbohydrate content and the relative expression of genes involved in sucrose metabolism indicated that carbohydrate metabolism was accelerated in ett1 under heat stress. Energy parameters, including the adenosine triphosphate (ATP) content and the energy charge, were significantly higher in the ett1 mutants than in WT plants under heat stress. Importantly, exogenous glucose can alleviate the damages on rice seedling plants caused by heat stress. CONCLUSION: RGA1 negatively regulates the thermo-tolerance in rice seedling plants through affecting carbohydrate and energy metabolism.
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As a newly discovered mechanism of cell death, disulfidptosis is expected to help diagnose and treat bladder cancer patients. First, data obtained from public databases were analyzed using bioinformatics techniques. SVA packages were used to combine data from different databases to remove batch effects. Then, the differential analysis and COX regression analysis of ten disulfidptosis-related genes identified four prognostically relevant differentially expressed genes which were subjected to Lasso regression for further screening to obtain model-related genes and output model formulas. The predictive power of the prognostic model was verified and the immunohistochemistry of model-related genes was verified in the HPA database. Pathway enrichment analysis was performed to identify the mechanism of bladder cancer development and progression. The tumor microenvironment and immune cell infiltration of bladder cancer patients with different risk scores were analyzed to personalize treatment. Then, information from the IMvigor210 database was used to predict the responsiveness of different risk patients to immunotherapy. The oncoPredict package was used to predict the sensitivity of patients at different risk to chemotherapy drugs, and its results have some reference value for guiding clinical use. After confirming that our model could reliably predict the prognosis of bladder cancer patients, the risk scores were combined with clinical information to create a nomogram to accurately calculate the patient survival rate. A prognostic model containing three disulfidptosis-related genes (NDUFA11, RPN1, SLC3A2) was constructed. The functional enrichment analysis and immune-related analysis indicated patients in the high-risk group were candidates for immunotherapy. The results of drug susceptibility analysis can guide more accurate treatment for bladder cancer patients and the nomogram can accurately predict patient survival. NDUFA11, RPN1, and SLC3A2 are potential novel biomarkers for the diagnosis and treatment of bladder cancer. The comprehensive analysis of tumor immune profiles indicated that patients in the high-risk group are expected to benefit from immunotherapy.
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Inmunoterapia , Neoplasias de la Vejiga Urinaria , Humanos , Neoplasias de la Vejiga Urinaria/genética , Neoplasias de la Vejiga Urinaria/terapia , Biología Computacional , Bases de Datos Factuales , Microambiente Tumoral/genéticaRESUMEN
Low-light stress compromises photosynthetic and energy efficiency and leads to spikelet sterility; however, the effect of low-light stress on pollen tube elongation in the pistil remains poorly understood. The gene RGA1, which encodes a Gα-subunit of the heterotrimeric G-protein, enhanced low-light tolerance at anthesis by preventing the cessation of pollen tube elongation in the pistil of rice plants. In this process, marked increases in the activities of acid invertase (INV), sucrose synthase (SUS) and mitochondrial respiratory electron transport chain complexes, as well as the relative expression levels of SUTs (sucrose transporter), SWEETs (sugars will eventually be exported transporters), SUSs, INVs, CINs (cell-wall INV 1), SnRK1A (sucrose-nonfermenting 1-related kinase 1) and SnRK1B, were observed in OE-1 plants. Accordingly, notable increases in contents of ATP and ATPase were presented in OE-1 plants under low-light conditions, while they were decreased in d1 plants. Importantly, INV and ATPase activators (sucrose and Na2 SO3 , respectively) increased spikelet fertility by improving the energy status in the pistil under low-light conditions, and the ATPase inhibitor Na2 VO4 induced spikelet sterility and decreased ATPase activity. These results suggest that RGA1 could alleviate the low-light stress-induced impairment of pollen tube elongation to increase spikelet fertility by promoting sucrose unloading in the pistil and improving the metabolism and allocation of energy.
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Infertilidad , Oryza , Azúcares/metabolismo , Tubo Polínico , Plantas/metabolismo , Proteínas de Transporte de Membrana/metabolismo , Sacarosa/metabolismo , Adenosina Trifosfatasas/metabolismo , Oryza/genéticaRESUMEN
Irrigation has been considered an effective approach for decreasing cadmium (Cd) uptake and accumulation in rice (Oryza sativa), but increasing evidence shows that the effects of different water management strategies on Cd accumulation in rice are contradictory in different studies, and the detailed regulatory mechanisms remain unconfirmed. Most previous studies have shown that irrigation regulates Cd accumulation in rice mainly by affecting Cd bioavailability, pH and redox potential (Eh) in soil, and few reports have focused on the function of oxygen (O2) in regulating the physiological mechanisms of rice on Cd tolerance or accumulation. Here, we concluded that irrigation affects Cd bioavailability, pH and Eh in soil mainly by regulating O2 content. In addition, recent studies have also shown that irrigation-regulated O2 also affects Cd accumulation in rice by affecting iron plaque (IP), the radial oxygen loss (ROL) barrier, the cell wall and mass flow in rice roots. All these results indicate that O2 is the key factor in irrigation-regulated Cd accumulation in rice, and dramatic result variations from different irrigation experiments are due to the different rhizosphere O2 conditions. This review will help clarify the effects and regulatory mechanisms of irrigation on Cd accumulation in rice and reveal the roles of O2 in this process.
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Oryza , Contaminantes del Suelo , Cadmio/análisis , Oryza/química , Oxígeno , Suelo/química , Contaminantes del Suelo/análisis , Agua , Abastecimiento de AguaRESUMEN
Oligomeric proanthocyanidins (OPCs) are abundant polyphenols found in foods and botanicals that benefit human health, but our understanding of the functions of OPCs in rice plants is limited, particularly under cold stress. Two rice genotypes, named Zhongzao39 (ZZ39) and its recombinant inbred line RIL82, were subjected to cold stress. More damage was caused to RIL82 by cold stress than to ZZ39 plants. Transcriptome analysis suggested that OPCs were involved in regulating cold tolerance in the two genotypes. A greater increase in OPCs content was detected in ZZ39 than in RIL82 plants under cold stress compared to their respective controls. Exogenous OPCs alleviated cold damage of rice plants by increasing antioxidant capacity. ATPase activity was higher and poly (ADP-ribose) polymerase (PARP) activity was lower under cold stress in ZZ39 than in RIL82 plants. Importantly, improvements in cold tolerance were observed in plants treated with the OPCs and 3-aminobenzamide (PARP inhibitor, 3ab) combination compared to the seedling plants treated with H2O, OPCs, or 3ab alone. Therefore, OPCs increased ATPase activity and inhibited PARP activity to provide sufficient energy for rice seedling plants to develop antioxidant capacity against cold stress.
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BACKGROUND: Glutathione (GSH) is important for plants to resist abiotic stress, and a large amount of energy is required in the process. However, it is not clear how the energy status affects the accumulation of GSH in plants under cold stress. RESULTS: Two rice pure lines, Zhongzao39 (ZZ39) and its recombinant inbred line 82 (RIL82) were subjected to cold stress for 48 h. Under cold stress, RIL82 suffered more damages than ZZ39 plants, in which higher increases in APX activity and GSH content were showed in the latter than the former compared with their respective controls. This indicated that GSH was mainly responsible for the different cold tolerance between these two rice plants. Interestingly, under cold stress, greater increases in contents of carbohydrate, NAD(H), NADP(H) and ATP as well as the expression levels of GSH1 and GSH2 were showed in RIL82 than ZZ39 plants. In contrast, ATPase content in RIL82 plants was adversely inhibited by cold stress while it increased significantly in ZZ39 plants. This indicated that cold stress reduced the accumulation of GSH in RIL82 plants mainly due to the inhibition on ATP hydrolysis rather than energy deficit. CONCLUSION: We inferred that the energy status determined by ATP hydrolysis involved in regulating the cold tolerance of plants by controlling GSH synthesis.
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Heat stress impairs both pollen germination and pollen tube elongation, resulting in pollination failure caused by energy imbalance. Invertase plays a critical role in the maintenance of energy homoeostasis; however, few studies investigated this during heat stress. Two rice cultivars with different heat tolerance, namely, TLY83 (heat tolerant) and LLY722 (heat susceptible), were subjected to heat stress. At anthesis, heat stress significantly decreased spikelet fertility, accompanied by notable reductions in pollen germination on stigma and pollen tube elongation in ovule, especially in LLY722. Acid invertase (INV), rather than sucrose synthase, contributed to sucrose metabolism, which explains the different tolerances of both cultivars. Under heat stress, larger enhancements in NAD(H), ATP, and antioxidant capacity were found in TLY83 compared with LLY722, whereas a sharp reduction in poly(ADP-ribose) polymerase (PARP) activity was found in the former compared with the latter. Importantly, exogenous INV, 3-aminobenzamide (a PARP inhibitor), sucrose, glucose, and fructose significantly increased spikelet fertility under heat stress, where INV activity was enhanced and PARP activity was inhibited. Therefore, INV can balance the energy production and consumption to provide sufficient energy for pollen germination and pollen tube growth under heat stress.
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Oryza/enzimología , Proteínas de Plantas/fisiología , beta-Fructofuranosidasa/fisiología , Adenosina Trifosfato/metabolismo , Antioxidantes/metabolismo , Metabolismo Energético , Flores/crecimiento & desarrollo , Flores/fisiología , Glucosiltransferasas/metabolismo , Respuesta al Choque Térmico , Homeostasis , Peróxido de Hidrógeno/metabolismo , NAD/metabolismo , NADP/metabolismo , Oryza/metabolismo , Oryza/fisiología , Proteínas de Plantas/metabolismo , Polen/fisiología , beta-Fructofuranosidasa/metabolismoRESUMEN
BACKGROUND: Aeration and water management increasing rhizosphere oxygen amount significantly promote rice (Oryza sativa) growth and yield, but the effect of root aeration on cadmium (Cd) toxicity and accumulation in rice seedlings under hydroponic culture remains unclear. RESULTS: Results showed that aeration promoted rice seedling growth and alleviated Cd toxicity. Transverse section discovered that Cd accelerated root mature and senescence while aeration delayed the mature and senescence of roots. Non-invasive Micro-test Technology (NMT) showed that aeration increased net O2 and Cd2+ influxes on the surface of roots while decreased net Cd2+ influx in xylem. Perls blue staining showed that aeration and Cd treatments increased iron plaque formation on the surface of roots. Results of metal concentration analysis showed that besides increasing Cd retention in iron plaque, aeration also increasing Cd retention in the cell wall of rice roots. Cell wall component analysis showed that aeration not only increased pectin content but also decreased pectin methylesterification degree (PMD) by increasing pectin methylesterase (PME) activity. CONCLUSIONS: All of these results indicate that aeration not only delays root mature and senescence but also increases Cd retention in roots by enhancing iron plaque formation and regulating pectin synthesis in the roots of rice seedlings.
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Down syndrome (DS, trisomy 21) is associated with developmental abnormalities and increased leukemia risk. To reconcile chromatin alterations with transcriptome changes, we performed paired exogenous spike-in normalized RNA and chromatin immunoprecipitation sequencing in DS models. Absolute normalization unmasks global amplification of gene expression associated with trisomy 21. Overexpression of the nucleosome binding protein HMGN1 (encoded on chr21q22) recapitulates transcriptional changes seen with triplication of a Down syndrome critical region on distal chromosome 21, and HMGN1 is necessary for B cell phenotypes in DS models. Absolute exogenous-normalized chromatin immunoprecipitation sequencing (ChIP-Rx) also reveals a global increase in histone H3K27 acetylation caused by HMGN1. Transcriptional amplification downstream of HMGN1 is enriched for stage-specific programs of B cells and B cell acute lymphoblastic leukemia, dependent on the developmental cellular context. These data offer a mechanistic explanation for DS transcriptional patterns and suggest that further study of HMGN1 and RNA amplification in diverse DS phenotypes is warranted.
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Síndrome de Down/genética , Proteína HMGN1/genética , Transcripción Genética , Trisomía/genética , Acetilación , Animales , Linfocitos B/metabolismo , Línea Celular , Genoma , Proteína HMGN1/metabolismo , Histonas/metabolismo , Humanos , Lisina/metabolismo , Ratones Endogámicos C57BL , Modelos Genéticos , Nucleosomas/metabolismo , Fenotipo , ARN/genética , Transcriptoma/genética , Regulación hacia Arriba/genéticaRESUMEN
Acute myeloid leukemia (AML) is a heterogeneous disease with complex molecular pathophysiology. To systematically characterize AML's genetic dependencies, we conducted genome-scale short hairpin RNA screens in 17 AML cell lines and analyzed dependencies relative to parallel screens in 199 cell lines of other cancer types. We identified 353 genes specifically required for AML cell proliferation. To validate the in vivo relevance of genetic dependencies observed in human cell lines, we performed a secondary screen in a syngeneic murine AML model driven by the MLL-AF9 oncogenic fusion protein. Integrating the results of these interference RNA screens and additional gene expression data, we identified the transcription factor ZEB2 as a novel AML dependency. ZEB2 depletion impaired the proliferation of both human and mouse AML cells and resulted in aberrant differentiation of human AML cells. Mechanistically, we showed that ZEB2 transcriptionally represses genes that regulate myeloid differentiation, including genes involved in cell adhesion and migration. In addition, we found that epigenetic silencing of the miR-200 family microRNAs affects ZEB2 expression. Our results extend the role of ZEB2 beyond regulating epithelial-mesenchymal transition (EMT) and establish ZEB2 as a novel regulator of AML proliferation and differentiation.
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Transición Epitelial-Mesenquimal/genética , Regulación Neoplásica de la Expresión Génica , Predisposición Genética a la Enfermedad , Proteínas de Homeodominio/genética , Leucemia Mieloide Aguda/genética , MicroARNs/genética , Proteínas Represoras/genética , Animales , Adhesión Celular , Diferenciación Celular , Línea Celular Tumoral , Movimiento Celular , Epigénesis Genética , Perfilación de la Expresión Génica , Estudio de Asociación del Genoma Completo , Proteínas de Homeodominio/antagonistas & inhibidores , Proteínas de Homeodominio/metabolismo , Humanos , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patología , Ratones , MicroARNs/metabolismo , Proteínas de Fusión Oncogénica/genética , Proteínas de Fusión Oncogénica/metabolismo , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , Proteínas Represoras/antagonistas & inhibidores , Proteínas Represoras/metabolismo , Transducción de Señal , Transcripción Genética , Caja Homeótica 2 de Unión a E-Box con Dedos de ZincRESUMEN
Iron (Fe) is essential for rice growth and humans consuming as their staple food but is often deficient because of insoluble Fe(III) in soil for rice growth and limited assimilation for human bodies, while cadmium (Cd) is non-essential and toxic for rice growth and humans if accumulating at high levels. Over-accumulated Cd can cause damage to human bodies. Selecting and breeding Fe-rich but Cd-free rice cultivars are ambitious, challenging and meaningful tasks for researchers. Although evidences show that the mechanisms of Fe/Cd uptake and accumulation in rice are common to some extent as a result of similar entry routes within rice, an increasing number of researchers have discovered distinct mechanisms between Fe/Cd uptake and accumulation in rice. This comprehensive review systematically elaborates and compares cellular mechanisms of Fe/Cd uptake and accumulation in rice, respectively. Mechanisms for maintaining Fe homeostasis and Cd detoxicification are also elucidated. Then, effects of different fertilizer management on Fe/Cd accumulation in rice are discussed. Finally, this review enumerates various approaches for reducing grain Cd accumulation and enhancing Fe content in rice. In summary, understanding of discrepant cellular mechanisms of Fe/Cd accumulation in rice provides guidance for cultivating Fe-fortified rice and has paved the way to develop rice that are tolerant to Cd stress, aiming at breeding Fe-rich but Cd-free rice.
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Leukemia stem cells (LSCs) have the capacity to self-renew and propagate disease upon serial transplantation in animal models, and elimination of this cell population is required for curative therapies. Here, we describe a series of pooled, in vivo RNAi screens to identify essential transcription factors (TFs) in a murine model of acute myeloid leukemia (AML) with genetically and phenotypically defined LSCs. These screens reveal the heterodimeric, circadian rhythm TFs Clock and Bmal1 as genes required for the growth of AML cells in vitro and in vivo. Disruption of canonical circadian pathway components produces anti-leukemic effects, including impaired proliferation, enhanced myeloid differentiation, and depletion of LSCs. We find that both normal and malignant hematopoietic cells harbor an intact clock with robust circadian oscillations, and genetic knockout models reveal a leukemia-specific dependence on the pathway. Our findings establish a role for the core circadian clock genes in AML.
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Factores de Transcripción ARNTL/genética , Proteínas CLOCK/genética , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patología , Células Madre Neoplásicas/patología , Animales , Ritmo Circadiano , Modelos Animales de Enfermedad , Técnicas de Inactivación de Genes , Hematopoyesis , Humanos , Leucemia Mieloide Aguda/metabolismo , Ratones , Ratones Endogámicos C57BL , Células Madre Neoplásicas/metabolismo , Interferencia de ARN , ARN Interferente Pequeño/metabolismoRESUMEN
Down syndrome confers a 20-fold increased risk of B cell acute lymphoblastic leukemia (B-ALL), and polysomy 21 is the most frequent somatic aneuploidy among all B-ALLs. Yet the mechanistic links between chromosome 21 triplication and B-ALL remain undefined. Here we show that germline triplication of only 31 genes orthologous to human chromosome 21q22 confers mouse progenitor B cell self renewal in vitro, maturation defects in vivo and B-ALL with either the BCR-ABL fusion protein or CRLF2 with activated JAK2. Chromosome 21q22 triplication suppresses histone H3 Lys27 trimethylation (H3K27me3) in progenitor B cells and B-ALLs, and 'bivalent' genes with both H3K27me3 and H3K4me3 at their promoters in wild-type progenitor B cells are preferentially overexpressed in triplicated cells. Human B-ALLs with polysomy 21 are distinguished by their overexpression of genes marked with H3K27me3 in multiple cell types. Overexpression of HMGN1, a nucleosome remodeling protein encoded on chromosome 21q22 (refs. 3,4,5), suppresses H3K27me3 and promotes both B cell proliferation in vitro and B-ALL in vivo.
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Linfocitos B/citología , Duplicación de Gen , Proteína HMGN1/genética , Histonas/metabolismo , Lisina/genética , Animales , Trasplante de Médula Ósea , Proliferación Celular , Cromosomas Humanos Par 21 , Metilación de ADN , Femenino , Proteínas de Fusión bcr-abl/metabolismo , Humanos , Masculino , Metilación , Ratones , Ratones Endogámicos C57BL , Nucleosomas/metabolismo , Fenotipo , Regiones Promotoras GenéticasRESUMEN
Using a genome-scale, lentivirally delivered shRNA library, we performed massively parallel pooled shRNA screens in 216 cancer cell lines to identify genes that are required for cell proliferation and/or viability. Cell line dependencies on 11,000 genes were interrogated by 5 shRNAs per gene. The proliferation effect of each shRNA in each cell line was assessed by transducing a population of 11M cells with one shRNA-virus per cell and determining the relative enrichment or depletion of each of the 54,000 shRNAs after 16 population doublings using Next Generation Sequencing. All the cell lines were screened using standardized conditions to best assess differential genetic dependencies across cell lines. When combined with genomic characterization of these cell lines, this dataset facilitates the linkage of genetic dependencies with specific cellular contexts (e.g., gene mutations or cell lineage). To enable such comparisons, we developed and provided a bioinformatics tool to identify linear and nonlinear correlations between these features.
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Linaje de la Célula/genética , Proliferación Celular/genética , Regulación Neoplásica de la Expresión Génica , Mutación , Línea Celular Tumoral , ADN de Neoplasias , Genómica , Humanos , Neoplasias/genética , Neoplasias/patología , ARN Interferente PequeñoRESUMEN
TNFAIP8-like 2 (TIPE2) has an essential role in immune homeostasis, yet the underlying mechanism remains enigmatic. The high-resolution crystal structure of TIPE2 reveals a previously uncharacterized fold that is different from the predicted fold of a death effector domain (DED). Strikingly, TIPE2 contains a large, hydrophobic central cavity that is poised for cofactor binding. These structural features will be important for understanding the functions of TIPE2 and other TNFAIP8 family proteins.