This is a class prediction experiment, where the class is the response status to imatinib (also called Gleevec), a drug used to treat patients with chronic myelogenous leukemia (CML). There are two data sets, a training set (from Leipzig, 8 Responders and 5 Non-Responders) and a validation set (from Mannheim, 8 Responders and 7 Non-Responders). The objective is to identify differentially regulated genes between CML patients who respond and those who do not respond to imatinib and confirm the results in the validation data set. The samples from blood or bone marrow of CML patients were hybridized to Affymetrix HG-U95Av2 chip and RMA was used to generate the normalized signal values.
In chronic myeloid leukemia white cells from cytogenetic responders and non-responders to imatinib have very similar gene expression signatures.
No sample metadata fields
View SamplesProfiling CD34+ BCR-ABL+ cells of CML patients in chronic phase or blast crisis to identify differentially expressed stage-specific genes.
Gene expression profiling of CD34+ cells identifies a molecular signature of chronic myeloid leukemia blast crisis.
Sex, Age, Specimen part, Disease, Disease stage
View SamplesCellular reprogramming from somatic cells to induced pluripotent stem cells (iPSCs) can be achieved through forced expression of the transcription factors Oct4, Klf4, Sox2 and c-Myc (OKSM). These factors, in combination with environmental cues, induce a stable intrinsic pluripotency network that confers indefinite self-renewal capacity on iPSCs. In addition to Oct4 and Sox2, the homeodomain-containing transcription factor Nanog is an integral part of the pluripotency network. Although Nanog expression is not required for the maintenance of pluripotent stem cells, it has been reported to be essential for the establishment of both embryonic stem cells (ESCs) from blastocysts and iPSCs from somatic cells. Here we revisit the role of Nanog in direct reprogramming. Surprisingly, we find that Nanog is dispensable for iPSC formation under optimized culture conditions. We further document that Nanog-deficient iPSCs are transcriptionally highly similar to wild-type iPSCs and support the generation of teratomas and chimeric mice. Lastly, we provide evidence that the presence of ascorbic acid in the culture media is critical for overcoming the previously observed reprogramming block of Nanog knockout cells.
Nanog is dispensable for the generation of induced pluripotent stem cells.
Specimen part
View SamplesDirect reprogramming of human fibroblasts to a pluripotent state has been achieved through ectopic expression of the transcription factors OCT4, SOX2, and either cMYC and KLF4 or NANOG and LIN28. Little is known, however, about the mechanisms by which reprogramming occurs, which is in part limited by the low efficiency of conversion. To this end, we sought to create a doxycycline-inducible lentiviral system to convert primary human fibroblasts and keratinocytes into human induced pluripotent stem (hiPS) cells. hiPS cells generated with this system were molecularly and functionally similar to human embryonic stem (hES) cells, demonstrated by gene expression profiles, DNA methylation status, and differentiation potential. While expression of the viral transgenes was required for several weeks in fibroblasts, we found that 10 days was sufficient for the reprogramming of keratinocytes, suggesting that the kinetics of reprogramming are cell-type dependent. Using our inducible system, we developed a strategy to induce hiPS cell formation at high frequency by generating differentiated cells that contain the viral transgenes in a pattern that enables successful induction of pluripotency. Upon addition of doxycycline to differentiated hiPS-derived cells, we obtained secondary hiPS cells at a frequency at least 100-fold greater than the initial conversion. The ability to reprogram cells with high efficiency provides a unique platform to dissect the underlying molecular and biochemical processes that accompany nuclear reprogramming.
A high-efficiency system for the generation and study of human induced pluripotent stem cells.
No sample metadata fields
View SamplesIn order to investigate the function of STAT5 in ALL, we isolated bone marrow cells from STAT5 fl/fl mice and transformed them with BCR-ABL1. In a second transduction the BCR-ABL1 driven pre-B cells were transformed either with CRE-GFP or empty vector control (GFP) and subjected to gene expression analysis.
BCL6-mediated repression of p53 is critical for leukemia stem cell survival in chronic myeloid leukemia.
Age, Disease, Disease stage
View SamplesThe reprogramming of somatic cells into induced pluripotent stem cells (iPSCs) upon overexpression of OCT4, KLF4, SOX2 and c-MYC (OKSM) provides a powerful system to interrogate basic mechanisms of cell fate change. However, iPSC formation with standard methods is typically protracted and inefficient, resulting in heterogeneous cell populations. We show that exposure of OKSM-expressing cells to both ascorbic acid and a GSK3- inhibitor (AGi) facilitates more synchronous and rapid iPSC formation from several mouse cell types. AGi treatment restored the ability of refractory cell populations to yield iPSC colonies, and it attenuated the activation of developmental regulators commonly observed during the reprogramming process. Moreover, AGi supplementation gave rise to chimera-competent iPSCs after as little as 48 h of OKSM expression. Our results offer a simple modification to the reprogramming protocol, facilitating iPSC induction at unparalleled efficiencies and enabling dissection of the underlying mechanisms in more homogeneous cell populations.
Small molecules facilitate rapid and synchronous iPSC generation.
Specimen part, Treatment, Time
View SamplesPpp2r1afl/fl mouse bone marrow pre-B cells were transduced with an BCR-ABL1 vector. The BCR-ABL1 transduced Ppp2r1afl/fl pre-B cells were then transduced with an empty vector (EV), or a Cre vector for Cre-mediated PP2A deletion. Effect of PP2A deletion in the BCR-ABL1 pre-B cells were studied by Affymetrix GeneChip Mouse Genome ST1.0 Array
B-Cell-Specific Diversion of Glucose Carbon Utilization Reveals a Unique Vulnerability in B Cell Malignancies.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Aberrant silencing of imprinted genes on chromosome 12qF1 in mouse induced pluripotent stem cells.
Specimen part
View SamplesInduced pluripotent stem cells (iPSCs) can be generated by enforced expression of defined transcription factors in somatic cells. It remains controversial whether iPSCs are equivalent to blastocyst-derived embryonic stem cells (ESCs). Using genetically matched cells, we found that the overall mRNA expression patterns of these cell types are indistinguishable with the exception of a few transcripts encoded on chromosome 12qF1.
Aberrant silencing of imprinted genes on chromosome 12qF1 in mouse induced pluripotent stem cells.
Specimen part
View SamplesAutosomal recessive polycystic kidney disease is a severe, monogenetically inherited kidney and liver disease and PCK rats carrying the orthologous mutant gene serve as a model of human disease. We combined selective MALDI imaging of sulfated kidney lipids and Fisher discriminant analysis of imaging data sets for identification of candidate lipid markers of progressive disease in PCK rats. Our study highlights strong increases in lower mass lipids as main classifiers of cystic disease. Structure determination by high resolution mass spectrometry identifies these altered lipids as taurine-conjugated bile acids. Beside increased levels of serum-cholesterol these sulfated lipids are selectively elevated in the PCK rat model but not in models of related hepatorenal fibrocystic diseases suggesting that they be molecular markers of the disease.
MALDI imaging MS reveals candidate lipid markers of polycystic kidney disease.
Sex, Age, Specimen part, Disease, Disease stage
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