The E-protein transcription factors E2A and HEB play important roles at several stages of hematopoiesis. However, the exact mechanism for theire action and the main targets in the LY6D negative common lymphoid progentior (CLP) compartment remains unknown. By adressing this question, we will gain important infromation regarding the early events leading to B-cell specification.
The transcription factors E2A and HEB act in concert to induce the expression of FOXO1 in the common lymphoid progenitor.
Specimen part
View SamplesIn order to investigate molecular events involved in the regulation of lymphoid lineage commitment, we crossed lamda5 reporter transgenic mice to mice where the GFP gene is inserted into the Rag1 locus. This allowed us to sub-fractionate common lymphoid progenitors (CLPs) and pre-pro-B cells into lamda5-Rag1low, lamda5-Rag1high and lamda5+Rag1high cells. Clonal in vitro differentiation analysis demonstrated that Rag1low cells gave rise to B/T and NK cells. Rag1high cells displayed reduced NK-cell potential with preserved capacity to generate B- and T-lineage cells while the lamda5+ cells were B-lineage restricted. Ebf1 and Pax5 expression was largely confined to the Rag1high populations. These cells also expressed a higher level of the surface protein LY6D providing an additional tool for the analysis of early lymphoid development. These data suggest that the classical CLP compartment composes a mixture of cells with more or less restricted lineage potentials opening new possibilities to investigate early hematopoiesis.
Single-cell analysis of the common lymphoid progenitor compartment reveals functional and molecular heterogeneity.
Specimen part
View SamplesLoss of one allele of Ebf1 impairs pre-B cell (B220+CD19+CD43low/negIgM-) expansion. In order to better understand the underlying cause of the reduced pre-B cell compartment in Ebf1+/- mice, we sorted pro-B (B220+CD19+CD43highIgM- ) as well as pre-B cells from Wt and Ebf1 heterozygote mutant mice and performed Affymetrix based microarray gene expression analysis.
Early B-cell factor 1 regulates the expansion of B-cell progenitors in a dose-dependent manner.
Specimen part
View SamplesFoxo1 and Ebf1 deficiency leads to a similar disruption of normal B-cell development at the level of the common lymphoid progenitor (CLP). Both mouse strains display the existance of LY6D+ CLPs but a marked/complete lack of proB cells.
Positive intergenic feedback circuitry, involving EBF1 and FOXO1, orchestrates B-cell fate.
Specimen part
View Samplesneuroblastoma cells derived from PDOX models were treated with the kinase inhibitor. Overall design: 5 repetitions of control and IBL-302 treated cells were harvest and submitted for RNAseq analysis
Anti-tumor effects of PIM/PI3K/mTOR triple kinase inhibitor IBL-302 in neuroblastoma.
Specimen part, Treatment, Subject
View SamplesOur earlier study demonstrated that when CFSE-labeled LCMV-or Pichinde virus-immune spleen leukocytes were transferred into T cell-deficient hosts, the bona fide virus-specific memory cells underwent relatively limited cell division and were substantially diluted in frequency by other more extensively proliferating cells originating from that donor cell population. We questioned how the slowly dividing population, which contained bona fide memory cells, differed from the rapidly dividing cells, which contained memory-like cells. As a preliminary screen we performed a comparative genome-wide microarray analysis of genes expressed on sorted rapidly proliferating (CFSE-low) and slowly proliferating (CFSE-high) CD8 cell populations
Programmed death-1 (PD-1) defines a transient and dysfunctional oligoclonal T cell population in acute homeostatic proliferation.
Age, Specimen part
View SamplesComparison of rosette leaves of two different RAP2.2 overexpressing lines with wild type leaves. The AP2/EREBP transcription factor RAP2.2 was shown to bind to a cis-acting motif within the phytoene synthase promoter from Arabidopsis. To investigate effects of increased RAP2.2 levels, two RAP2.2 overexpressing Arabidopsis thaliana (ecotype Wassilewskija) lines were generated: one line, nosr2, carried the nos promoter and showed a two-fold increase in RAP2.2 transcript level, the second line, cmr-5, carried four copies of the CaMV-35S enhancer and showed a 12-fold increase. However, neither weak nor strong increase in RAP2.2 transcript amounts had any effect on RAP2.2 protein levels as shown by Western blot analysis. The strong robustness of RAP2.2 protein levels towards transcriptional changes can be explained by specific protein degradation which includes SINAT2, an E3 ubiquitin ligase which was isolated using a two-hybrid approach. Accordingly, global gene expression analysis using both RAP2.2 overexpressing lines showed only minor transcriptional changes which are probably due to minor growth variation than to mechanisms involved in the down-regulation of RAP2.2 protein amounts.
Transcription factor RAP2.2 and its interacting partner SINAT2: stable elements in the carotenogenesis of Arabidopsis leaves.
Specimen part
View SamplesElevated levels of androgen receptor (AR) in prostate cancer confer resistance to current antiandrogens and play a causal role in disease progression due to persistent target gene activation. Through pharmacologic and genetic approaches, we show that half of all direct AR target genes, including TMPRSS2, the primary driver of ETS fusion transcripts in 70 percent of human prostate cancers, require histone deacetylase (HDAC) activity for transcriptional activation by AR. Surprisingly, the HDAC3-NCoR complex, which typically functions to repress gene expression by nuclear receptors, is required for AR target gene activation. Prostate cancer cells treated with HDAC inhibitors have reduced AR protein levels, but we show that the mechanism of blockade of AR activity is through failure to assemble a coactivator/RNA polymerase II complex after AR binds to the enhancers of target genes. Failed complex assembly is associated with a phase shift in the cyclical wave of AR recruitment that typically occurs in response to ligand treatment. HDAC inhibitors retain the ability to block AR activity in hormone refractory prostate cancer models and therefore merit clinical investigation in this setting. HDAC-regulated AR target genes defined here can serve as biomarkers to ensure sufficient levels of HDAC inhibition.
Histone deacetylases are required for androgen receptor function in hormone-sensitive and castrate-resistant prostate cancer.
No sample metadata fields
View SamplesThe Her-2/Neu-positive mouse breast cancer cell line was serially co-cultured with minced brain, bone marrow, and lung tissue in an intravital microscopy chamber mounted on the dorsal skinfold of nude mice, alternating with growth in vitro. Gene expression analysis was performed on the cells grown in culture after sorting and further growth in vitro. Gene expression under these growth conditions differed in time and according to the co-cultivated organ tissue. This study reveals genes that are expressed by cells as they adapt differentially to various foreign tissue microenvironments, and may represent a paradigm to discover gene expression changes that occur immediately upon extravasation when cancer metastasizes.
Effects of different tissue microenvironments on gene expression in breast cancer cells.
Cell line
View SamplesElevated levels of androgen receptor (AR) in prostate cancer confer resistance to current antiandrogens and play a causal role in disease progression due to persistent target gene activation. Through pharmacologic and genetic approaches, we show that half of all direct AR target genes, including TMPRSS2, the primary driver of ETS fusion transcripts in 70 percent of human prostate cancers, require histone deacetylase (HDAC) activity for transcriptional activation by AR. Surprisingly, the HDAC3-NCoR complex, which typically functions to repress gene expression by nuclear receptors, is required for AR target gene activation. Prostate cancer cells treated with HDAC inhibitors have reduced AR protein levels, but we show that the mechanism of blockade of AR activity is through failure to assemble a coactivator/RNA polymerase II complex after AR binds to the enhancers of target genes. Failed complex assembly is associated with a phase shift in the cyclical wave of AR recruitment that typically occurs in response to ligand treatment. HDAC inhibitors retain the ability to block AR activity in hormone refractory prostate cancer models and therefore merit clinical investigation in this setting. HDAC-regulated AR target genes defined here can serve as biomarkers to ensure sufficient levels of HDAC inhibition.
Histone deacetylases are required for androgen receptor function in hormone-sensitive and castrate-resistant prostate cancer.
No sample metadata fields
View Samples