Purpose: CEBPA mutations are found as either biallelic (biCEBPA) or monoallelic (moCEBPA). We set out to explore whether the kind of CEBPA mutation is of prognostic relevance in cytogenetically normal AML (CN-AML).
Acute myeloid leukemia with biallelic CEBPA gene mutations and normal karyotype represents a distinct genetic entity associated with a favorable clinical outcome.
Specimen part
View SamplesAcute myeloid leukemia (AML) is a heterogeneous disease in respect of molecular aberrations and prognosis. We used gene expression profiling of 562 patients treated in the German AMLCG 1999 trial to develop a gene signature that predicts survival in AML.
A 29-gene and cytogenetic score for the prediction of resistance to induction treatment in acute myeloid leukemia.
Age, Specimen part
View SamplesPatients with cytogenetically normal acute myeloid leukemia (CN-AML) show heterogeneous treatment outcomes. We used gene expression profiling to develop a gene signature that predicts overall survival (OS) in CN-AML. Based on data from 163 patients treated in the German AMLCG 1999 trial and analyzed on oligonucleotide microarrays, we used supervised principal component analysis to identify 86 probe sets (representing 66 different genes) which correlated with OS, and defined a prognostic score based on this signature. When applied to an independent cohort of 79 CN-AML patients, this continuous score remained a significant predictor for OS (hazard ratio [HR], 1.85; P=0.002), EFS (HR, 1.73; P=0.001), and RFS (HR, 1.76; P=0.025). It kept its prognostic value in multivariate analyses adjusting for age, FLT3 ITD and NPM1 status. In a validation cohort of 64 CN-AML patients treated on CALGB study 9621, the score also predicted OS (HR, 4.11; P<0.001), EFS (HR, 2.90; P<0.001), and RFS (HR, 3.14, P<0.001) and retained its significance in a multivariate model for OS. In summary, we present a novel gene expression signature that offers additional prognostic information for patients with CN-AML.
An 86-probe-set gene-expression signature predicts survival in cytogenetically normal acute myeloid leukemia.
No sample metadata fields
View SamplesResistance of Saccharomyces cerevisiae to high furfural concentration is based on NADPH-dependent reduction by at least two oxireductases.
Resistance of Saccharomyces cerevisiae to high concentrations of furfural is based on NADPH-dependent reduction by at least two oxireductases.
No sample metadata fields
View SamplesBiofilms are surface-adhered bacterial communities encased in an extracellular matrix composed of polysaccharides, proteins, and extracelluar (e)DNA, with eDNA being required for the formation and integrity of biofilms. Here we demonstrate that the spatial and temporal release of eDNA is regulated by BfmR, a regulator essential for Pseudomonas aeruginosa biofilm development. The expression of bfmR coincided with localized cell death and DNA release, with high eDNA concentrations localized to the outer part of microcolonies in the form of a ring and as a cap on small clusters. Additionally, eDNA release and cell lysis increased significantly following bfmR inactivation. Genome-wide transcriptional profiling indicated that bfmR was required for repression of genes associated with bacteriophage assembly and bacteriophage-mediated lysis. In order to determine which of these genes were directly regulated by BfmR, we utilized chromatin immunoprecipitation (ChIP) analysis to identify the promoter of PA0691, termed here phdA, encoding a previously undescribed homologue of the prevent-host-death (Phd) family of proteins. Lack of phdA expression coincided with impaired biofilm development, increased cell death and bacteriophage release, a phenotype comparable to bfmR. Expression of phdA in bfmR biofilms restored eDNA release, cell lysis, release of bacteriophages, and biofilm formation to wild type levels. Moreover, overexpression of phdA rendered P. aeruginosa resistant to lysis mediated by superinfective bacteriophage Pf4 which was only detected in biofilms. The expression of bfmR was stimulated by conditions resulting in membrane perturbation and cell lysis. Thus, we propose that BfmR regulates biofilm development by controlling bacteriophage-mediated lysis and thus, cell death and eDNA release, via PhdA.
The novel Pseudomonas aeruginosa two-component regulator BfmR controls bacteriophage-mediated lysis and DNA release during biofilm development through PhdA.
No sample metadata fields
View SamplesA hallmark of the biofilm architecture is the presence of microcolonies. However, little is known about the underlying mechanisms governing microcolony formation. In the human pathogen Pseudomonas aeruginosa, microcolony formation is dependent on the two-component regulator MifR, with mifR mutant biofilms exhibiting an overall thin structure lacking microcolonies, and overexpression of mifR resulting in hyper-microcolony formation. Here, we made use of the distinct MifR-dependent phenotypes to elucidate mechanisms associated with microcolony formation. Using global transcriptomic and proteomic approaches, we demonstrate that cells located within microcolonies experience stressful, oxygen limited, and energy starving conditions, as indicated by the activation of stress response mechanisms and anaerobic and fermentative processes, in particular pyruvate fermentation. Inactivation of genes involved in pyruvate utilization including uspK, acnA and ldhA abrogated microcolony formation in a manner similar to mifR inactivation. Moreover, depletion of pyruvate from the growth medium impaired biofilm and microcolony formation, while addition of pyruvate significantly increased microcolony formation. Addition of pyruvate partly restored microcolony formation in mifR biofilms. Moreover, addition of pyruvate to or expression of mifR in lactate dehydrogenase (ldhA) mutant biofilms did not restore microcolony formation. Consistent with the finding of denitrification genes not demonstrating distinct expression patterns in biofilms forming or lacking microcolonies, addition of nitrate did not alter microcolony formation. Our findings indicate the fermentative utilization of pyruvate to be a microcolony-specific adaptation to the oxygen limitation and energy starvation of the P. aeruginosa biofilm environment.
Microcolony formation by the opportunistic pathogen Pseudomonas aeruginosa requires pyruvate and pyruvate fermentation.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Unraveling condition-dependent networks of transcription factors that control metabolic pathway activity in yeast.
No sample metadata fields
View SamplesExpression data from wild-type FY4 and GCR2 deletion strain. Impact of the transcription factor Gcr2p on mRNA expression was investigated in the corresponding deletion strain in exponentially growing glucose minimal medium batch cultures.
Unraveling condition-dependent networks of transcription factors that control metabolic pathway activity in yeast.
No sample metadata fields
View SamplesThe impact on mRNA expression of the transcription factors Bas1, Pho2, Gcn4 and Gcr2p was investigated in the corresponding deletion strains during exponential growth in glucose minimal media batch cultures.
Unraveling condition-dependent networks of transcription factors that control metabolic pathway activity in yeast.
No sample metadata fields
View SamplesThe impact on mRNA expression of the transcription factors Bas1, Pho2, Gcn4 and Gcr2p was investigated in the corresponding deletion strains during exponential growth in glucose minimal media batch cultures.
Unraveling condition-dependent networks of transcription factors that control metabolic pathway activity in yeast.
No sample metadata fields
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