Constitutive activation of the Wnt pathway leads to adenoma formation, an obligatory step towards intestinal cancer. In view of the established role of Wnt in regulating stemness, we attempted the isolation of cancer stem cells (CSCs) from Apc- and Apc/KRAS-mutant intestinal tumours. Whereas CSCs are present in malignant Apc/KRASmutant carcinomas, they appear to be very rare (<10-6) in the benign Apcmutant adenomas. In contrast, the Lin-CD24hiCD29+ subpopulation of adenocarcinoma cells appear to be enriched in CSCs with increased levels of active -catenin. Expression profiling analysis of the CSC-enriched subpopulation confirmed their enhanced Wnt activity and revealed additional differential expression of other signalling pathways, growth factor binding proteins, and extracellular matrix components. As expected, genes characteristic of the Paneth cell lineage (e.g. defensins) are co-expressed together with stem cell genes (e.g. Lgr5) within the CSC-enriched subpopulation. This is of interest as it may indicate a cancer stem cell niche role for tumor-derived Paneth-like cells, similar to their role in supporting Lgr5+ stem cells in the normal intestinal crypt. Overall, our results indicate that oncogenic KRAS activation in Apc-driven tumours results in the expansion of the CSCs compartment by increasing b-catenin intracellular stabilization.
Cancer stemness in Apc- vs. Apc/KRAS-driven intestinal tumorigenesis.
Specimen part
View SamplesThe development, homeostasis and function of B lymphocytes involve multiple rounds of B cell receptor (BCR)-controlled proliferation and prolonged maintenance. We analyzed the role of transcription factor Zfx, a recently identified regulator of stem cell maintenance, in B cell development and homeostasis. Conditional Zfx deletion in the bone marrow blocked B cell development at the pre-BCR selection checkpoint. Zfx deficiency in peripheral B cells caused impaired generation of the B-1 cell lineage, accelerated B cell turnover, depletion of mature recirculating cells, and delayed T-dependent antibody responses. Zfx-deficient B cells showed normal proximal BCR signaling, but impaired BCR-induced proliferation and survival. This was accompanied by aberrantly enhanced and prolonged integrated stress response, and delayed induction of Cyclin D2 and Bcl-xL proteins. Thus, Zfx restrains the stress response and couples antigen receptor signaling to B cell expansion and maintenance during development and peripheral homeostasis.
Transcription factor Zfx controls BCR-induced proliferation and survival of B lymphocytes.
No sample metadata fields
View SamplesCell lines geneticially engineered to undergo conditional asymmetric self-renewal were used to identify genes whose expression is asymmetric self-renewal associated (ASRA). Non-random sister chromatid segregation occurs concordantly with asymmetric self-renewal in these cell lines.
A resource for discovering specific and universal biomarkers for distributed stem cells.
Cell line
View SamplesThe study of induced pluripotency often relies on experimental approaches that average measurements across a large population of cells, the majority of which do not become pluripotent. Here we used high-resolution, time-lapse imaging to trace the reprogramming process over 2 weeks from single mouse embryonic fibroblasts (MEFs) to pluripotency factor-positive colonies. This enabled us to calculate a normalized cell-of-origin reprogramming efficiency that takes into account only the initial MEFs that respond to form reprogrammed colonies rather than the larger number of final colonies. Furthermore, this retrospective analysis revealed that successfully reprogramming cells undergo a rapid shift in their proliferative rate that corresponds to a reduction in cellular area. This event occurs as early as the first cell division and with similar kinetics in all cells that form induced pluripotent stem (iPS) cell colonies. These data contribute to the theoretical modeling of reprogramming and suggest that certain parts of the reprogramming process follow defined rather than stochastic steps.
Dynamic single-cell imaging of direct reprogramming reveals an early specifying event.
Specimen part
View SamplesBone marrow macrophages were cultured from 16 week old apoE-deficient F2 mice from an AKRxDBA/2 intercross
Sex specific gene regulation and expression QTLs in mouse macrophages from a strain intercross.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Reprogramming factor expression initiates widespread targeted chromatin remodeling.
Specimen part
View SamplesPURPOSE To identify retinal genes and their relevant expression pathways affected by intravitreal injections of dexamethasone and triamcinolone acetonide in mice at clinically relevant time points for patient care.
In vivo gene expression profiling of retina postintravitreal injections of dexamethasone and triamcinolone at clinically relevant time points for patient care.
Sex, Specimen part
View SamplesCD25, the high affinity interleukin-2 (IL-2) receptor alpha-chain, is rapidly upregulated by antigen-specific CD8+ T cells after T cell receptor stimulation. We demonstrated that during an acute viral infection, CD25 expression was dynamic, and a subset of virus-specific CD8+ T cells sustained CD25 expression longer than the rest. Examination of the in vivo fate of effector CD8+ T cells exhibiting differential responsiveness to IL-2 revealed that CD25lo cells, which were relatively less sensitive to IL-2, preferentially upregulated CD127 and CD62L and gave rise to the functional long-lived memory pool. In contrast, CD25hi cells that accumulate enhanced IL-2 signals, proliferated more rapidly, were prone to apoptosis, exhibited a more pronounced effector phenotype, and appeared to be terminally differentiated. Sustained IL-2 receptor signaling resulted in increased CD8+ T cell proliferation, higher granzyme B expression and exaggerated contraction after antigen clearance. These data support the hypothesis that prolonged IL-2 signals during priming promote terminal effector differentiation of CD8+ T cells.
Prolonged interleukin-2Ralpha expression on virus-specific CD8+ T cells favors terminal-effector differentiation in vivo.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Transcriptional signatures of Itk-deficient CD3+, CD4+ and CD8+ T-cells.
No sample metadata fields
View SamplesThe capacity of the hematopoietic system to promptly respond to peripheral demands relies on adequate pools of progenitors able to transiently proliferate and differentiate in a regulated manner. However, little is known about factors that may restrain progenitor maturation to maintain their reservoirs. In addition to a profound defect in hematopoietic stem cell (HSC) self-renewal, conditional knockout mice for the Pbx1 proto-oncogene have a significant reduction in lineage-restricted progenitors, including common myeloid progenitors (CMPs) and, to a lesser extent, granulocyte-monocyte progenitors (GMPs).
Pbx1 restrains myeloid maturation while preserving lymphoid potential in hematopoietic progenitors.
Age, Specimen part
View Samples