This SuperSeries is composed of the SubSeries listed below.
Identification of the CIMP-like subtype and aberrant methylation of members of the chromosomal segregation and spindle assembly pathways in esophageal adenocarcinoma.
Specimen part
View Samplesgenome-wide methylation profile of 250 samples including 125 EAC, 19 Barretts, 64 normal adjacent squamous and 21 normal stomach. Transcriptome data was performed for 70 samples with methylation profile (48 EAC, 4 Barretts and 18 normal adjacent squamous). This is the first study to use methylome, transcriptome and ENCODE data to characterize the regulatory role of methylation in EAC.
Identification of the CIMP-like subtype and aberrant methylation of members of the chromosomal segregation and spindle assembly pathways in esophageal adenocarcinoma.
Specimen part
View SamplesGene expression analysis from erythroid progenitors (CD34+/CD71(high)/CD45- mononuclear cells from the bone marrow) of patients with Diamond-Blackfan anemia (due to RPS19 mutations) and control individuals.
Altered translation of GATA1 in Diamond-Blackfan anemia.
Specimen part, Disease
View SamplesCurrently there is no method available to predict response to farnesyltransferase inhibitors (FTI). We analyzed gene expression profiles from the bone marrow of patients from a phase 2 study of the FTI tipifarnib, in older adults with previously untreated acute myeloid leukemia (AML). The RASGRP1:APTX gene expression ratio was found to predict response to tipifarnib with the greatest accuracy. This two-gene ratio was validated by quantitative PCR (QPCR) in the newly diagnosed AML cohort. We further demonstrated that this classifier could predict response to tipifarnib in an independent set of 54 samples from relapsed or refractory AML, with a negative predictive value (NPV) and positive predictive value (PPV) of 92% and 28%, respectively (odds ratio of 4.4). The classifier also predicted for improved overall survival (154 vs 56 days, p = 0.0001), which was shown to be independent of other prognostic factors including a previously described gene expression classifier predictive of overall survival. Therefore, these data indicate that a two-gene expression assay may have utility in categorizing a population of AML patients who are more likely to respond to tipifarnib.
A 2-gene classifier for predicting response to the farnesyltransferase inhibitor tipifarnib in acute myeloid leukemia.
Sex, Age, Disease
View SamplesActivating mutations of G protein alpha subunits (Ga) occur in 4-5% of all human cancers1 but oncogenic alterations in beta subunits (Gb) have not been defined. Here we demonstrate that recurrent mutations in the Gb proteins GNB1 and GNB2 confer cytokine-independent growth and activate canonical G protein signaling. Multiple mutations in GNB1 affect the protein interface that binds Ga subunits as well as downstream effectors, and disrupt Ga-Gbg interactions. Different mutations in Gb proteins clustered to some extent based on lineage; for example, all eleven GNB1 K57 mutations were in myeloid neoplasms while 6 of 7 GNB1 I80 mutations were in B cell neoplasms. Expression of patient-derived GNB1 alleles in Cdkn2a-deficient bone marrow followed by transplantation resulted in either myeloid or B cell malignancies. In vivo treatment with the dual PI3K/mTOR inhibitor BEZ235 suppressed GNB1-induced signaling and markedly increased survival. In several human tumors, GNB1 mutations co-occurred with oncogenic kinase alterations, including BCR/ABL, JAK2 V617F and BRAF V600K. Co-expression of patient-derived GNB1 alleles with these mutant kinases resulted in inhibitor resistance in each context. Thus, GNB1 and GNB2 mutations confer transformed and resistance phenotypes across a range of human tumors and may be targetable with inhibitors of G protein signaling.
Mutations in G protein β subunits promote transformation and kinase inhibitor resistance.
Cell line, Time
View SamplesInactivating mutations in SMARCA4 (BRG1), a key SWI/SNF chromatin remodelling gene, underlie small cell carcinoma of the ovary, hypercalcemic type (SCCOHT). To reveal its druggable vulnerabilities, we perform kinase-focused RNAi screens and uncover that SMARCA4-deficient SCCOHT cells are highly sensitive to the inhibition of cyclin-dependent kinase 4/6 (CDK4/6). SMARCA4 loss causes profound downregulation of cyclin D1, which limits CDK4/6 kinase activity in SCCOHT cells and leads to in vitro and in vivo susceptibility to CDK4/6 inhibitors. SCCOHT patient tumors are deficient in cyclin D1 yet retain the retinoblastoma-proficient/p16INK4a-deficient profile associated with positive responses to CDK4/6 inhibitors. Thus, our findings indicate that CDK4/6 inhibitors, approved for a breast cancer subtype addicted to CDK4/6 activation, could be repurposed to treat SCCOHT. Moreover, our study suggests a novel paradigm whereby critically low oncogene levels, caused by loss of a driver tumor suppressor, may also be exploited therapeutically. Overall design: The effect of CDK6 knockdown and palbociclib treatment on SCCOHT cells.
CDK4/6 inhibitors target SMARCA4-determined cyclin D1 deficiency in hypercalcemic small cell carcinoma of the ovary.
Specimen part, Treatment, Subject
View SamplesMgrR is a newly characterized Hfq dependent small RNA RNA. The expression of MgrR is regulated by Two component system, PhoPQ regulon, which senses low Mg2+ in environment. It has been reported that Hfq-binding sRNAs base pair with target RNAs, frequently leading to rapid degradation of target messages or, less frequently, to stabilization, both of which can be assayed by using microarrays. In order to search for the target genes of MgrR, we therefore examined the consequences of MgrR expression on mRNA abundance under two conditions. In condition 1, the chromosomal copy of mgrR was deleted and MgrR was expressed for 15 from an induced plac-mgrR plasmid and compared to cells carrying a vector induced for the same period. In condition 2, the expression of mRNAs was compared in wild-type cells (mgrR+) and the mgrR deletion strain, both grown in LB; because MgrR levels are fairly high under our normal growth conditions, this allowed analysis of both the direct and indirect (long-term) effects of MgrR.
A PhoQ/P-regulated small RNA regulates sensitivity of Escherichia coli to antimicrobial peptides.
No sample metadata fields
View SamplesNeural precursor cells (NPCs) in the mammalian neocortex generate various neuronal and glial cell types in a developmental stage-dependent manner. Most neocortical NPCs lose their neurogenic potential after birth. We have previously shown that high mobility group A (HMGA) proteins confer the neurogenic potential on early-stage NPCs during the midgestation period, although the underlying mechanisms are not fully understood. Here we performed microarray analysis and compared expression profiles between control and HMGA2-overexpressed NPCs.
IMP2 regulates differentiation potentials of mouse neocortical neural precursor cells.
Specimen part
View SamplesPlant cells contain different O-acetylserine(thiol)lyase (OASTL) enzymes involved in Cys biosynthesis and located in different subcellular compartments. These enzymes are made up of a complex variety of isoforms resulting in different subcellular Cys pools. To unravel the contribution of cytosolic Cys to plant metabolism, we characterized the knockout oas-a1.1 and osa-a1.2 mutants, deficient in the most abundant cytosolic OASTL isoform in Arabidposis thaliana. Total intracellular Cys and glutathione concentrations were reduced, and the glutathione redox state was shifted in favour of its oxidized form. Interestingly, the capability of the mutants to chelate heavy metals did not differ from that of the wild type, but the mutants have an enhanced sensitivity to Cd. With the aim of establishing the metabolic network most influenced by the cytosolic Cys pool, we used the ATH1 GeneChip for evaluation of differentially expressed genes in the oas-a1.1 mutant grown under non-stress conditions. The transcriptomic footprints of mutant plants had predicted functions associated with various physiological responses that are dependent on reactive oxygen species and suggested that the mutant was oxidatively stressed. To further elucidate the specific function(s) of the OAS-A1 isoform in the adaptation response to cadmium we extended the trasncriptome experiment to the wild type and oas-a1.1 mutant plants exposed to Cd. The comparison of transcriptomic profiles showed a higher proportion of genes with altered expression in the mutant than in the wild type, highlighting up-regulated genes identified as of the general oxidative stress response rather than metal-responsive genes.
Knocking out cytosolic cysteine synthesis compromises the antioxidant capacity of the cytosol to maintain discrete concentrations of hydrogen peroxide in Arabidopsis.
Specimen part
View SamplesIn bacteria, the biosynthesis of cysteine is accomplished by two enzymes that are encoged by the cysK and cysM genes. CysM is also able to incorporate thiosulfate to produce S-sulfocysteine. In plant cells, the biosynthesis of cysteine occurs in the cytosol, mitochondria and chloroplasts. Chloroplasts contain two O-acetylserine(thiol)lyase homologs, which are encoded by the OAS-B and CS26 genes. An in vitro enzymatic analysis of the recombinant CS26 protein demonstrated that this isoform possesses S-sulfocysteine synthase activity and lacks O-acetylserine(thiol)lyase activity. In vivo functional analysis of this enzyme in knockout mutants demonstrated that mutation of cs26 suppressed the S-sulfocysteine synthase activity that was detected in wild type; furthermore, the mutants exhibited a growth phenotype, but penetrance depended on the light regime. The cs26 mutant plants also had reductions in chlorophyll content and photosynthetic activity (neither of which were observed in oas-b mutants), as well as elevated glutathione levels. However, cs26 leaves were not able to properly detoxify ROS, which accumulated to high levels under long-day growth conditions. The transcriptional profile of the cs26 mutant revealed that the mutation had a pleiotropic effect on many cellular and metabolic processes. Our finding reveals that S-sulfocysteine and the activity of S-sulfocysteine synthase play an important role in chloroplast function and are essential for light-dependent redox regulation within the chloroplast.
Arabidopsis S-sulfocysteine synthase activity is essential for chloroplast function and long-day light-dependent redox control.
No sample metadata fields
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