This SuperSeries is composed of the SubSeries listed below.
The B-cell receptor controls fitness of MYC-driven lymphoma cells via GSK3β inhibition.
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View SamplesSimilar to resting mature B cells, where the B-cell antigen receptor (BCR) is essential for cellular survival, surface BCR expression is conserved in most mature B cell lymphomas. The identification of activating BCR mutations and the growth disadvantage upon BCR knockdown of cells of certain lymphoma entities has led to the view that BCR signaling is required for tumour cell survival. Consequently, the BCR signaling machinery has become a new target in the therapy of B cell malignancies. Here, we studied the effects of BCR ablation on MYC-driven mouse B cell lymphomas and compared them to observations in human Burkitt lymphoma. Whereas BCR ablation did not, per se, significantly affect lymphoma growth, BCR-negative (BCR-) tumour cells rapidly disappeared in the presence of their BCR-expressing (BCR+) counterparts in vitro and in vivo. This required neither cellular contact, nor factors released by BCR+ tumour cells. Instead, BCR loss induced the rewiring of central carbon metabolism increasing the sensitivity of receptor-less lymphoma cells to nutrient restriction. The BCR attenuated GSK3 activity to support MYC-controlled gene expression. BCR- tumour cells exhibited increased GSK3 activity and were rescued from their competitive growth disadvantage by GSK3. BCR-negative lymphoma variants that restored competitive fitness, normalized GSK3 following constitutive activation of the MAPK pathway, commonly through Ras mutations. Similarly, in Burkitt lymphoma, activating RAS mutations may propagate Ig-crippled tumour cells, which usually represent a minority of the tumour bulk. Thus, while BCR expression enhances lymphoma cell fitness, BCR-targeted therapies may profit from combinations with drugs targeting BCR-less tumour cells.
The B-cell receptor controls fitness of MYC-driven lymphoma cells via GSK3β inhibition.
No sample metadata fields
View SamplesSimilar to resting mature B cells, where the B-cell antigen receptor (BCR) is essential for cellular survival, surface BCR expression is conserved in most mature B cell lymphomas. The identification of activating BCR mutations and the growth disadvantage upon BCR knockdown of cells of certain lymphoma entities has led to the view that BCR signaling is required for tumour cell survival. Consequently, the BCR signaling machinery has become a new target in the therapy of B cell malignancies. Here, we studied the effects of BCR ablation on MYC-driven mouse B cell lymphomas and compared them to observations in human Burkitt lymphoma. Whereas BCR ablation did not, per se, significantly affect lymphoma growth, BCR-negative (BCR-) tumour cells rapidly disappeared in the presence of their BCR-expressing (BCR+) counterparts in vitro and in vivo. This required neither cellular contact, nor factors released by BCR+ tumour cells. Instead, BCR loss induced the rewiring of central carbon metabolism increasing the sensitivity of receptor-less lymphoma cells to nutrient restriction. The BCR attenuated GSK3 activity to support MYC-controlled gene expression. BCR- tumour cells exhibited increased GSK3 activity and were rescued from their competitive growth disadvantage by GSK3. BCR-negative lymphoma variants that restored competitive fitness, normalized GSK3 following constitutive activation of the MAPK pathway, commonly through Ras mutations. Similarly, in Burkitt lymphoma, activating RAS mutations may propagate Ig-crippled tumour cells, which usually represent a minority of the tumour bulk. Thus, while BCR expression enhances lymphoma cell fitness, BCR-targeted therapies may profit from combinations with drugs targeting BCR-less tumour cells.
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No sample metadata fields
View SamplesPathways that govern normal stem cell (SC) function are often subverted in cancer. Here, we report the isolation to near purity of human normal mammary SC (hNMSCs), from cultured mammospheres, based on their ability to retain the lipophilic dye PKH26 as a consequence of their quiescent nature. We demonstrated that PKH26-positive cells possess all the characteristics of hNMSCs. The transcriptional profile of PKH26-positive cells (hNMSC signature) was able to predict biological and molecular features of breast cancers. By using markers of the hNMSC signature, we could prospectively isolate SCs from the normal gland and from breast tumors. Poorly-differentiated aggressive (G3) cancers displayed higher content of prospectively isolated cancer SCs, than well-differentiated less aggressive (G1) cancers. By comparing G3 and G1 tumors in xenotransplantation experiments, we directly demonstrated that G3s are enriched in cancer SCs. Our data support the notion that the heterogeneous phenotypical and molecular traits of human breast cancers are a function of their SC content.
Biological and molecular heterogeneity of breast cancers correlates with their cancer stem cell content.
Specimen part
View SamplesNo description.
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Sex, Specimen part, Disease, Disease stage, Cell line, Treatment, Race
View SamplesPolycomb proteins control proliferation and cellular transformation regulating DNA replication independently of cell cycle checkpoints
Polycomb proteins control proliferation and transformation independently of cell cycle checkpoints by regulating DNA replication.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Tet proteins connect the O-linked N-acetylglucosamine transferase Ogt to chromatin in embryonic stem cells.
Specimen part
View SamplesO-linked N-acetylglucosamine (O-GlcNAc ) transferase (OGT) activity is essential for embryonic stem (ES) cell viability and mouse development. OGT is present in both cytoplasm and nucleus of different cell types and mediates serine or threonine glycosylation. The Ogt gene locus resides on the X-chromosome and its activity is required for the viability of male ES cells. Using Ogt conditional knock out (KO) ES cells it was shown the failure of establishing stable KO ES clones further suggesting that Ogt activity is required for ES cell self-renewal and pluripotency. For understanding these changes, we performed global gene expression upon silencing of Ogt mediated by esiRNA in mouse Embryonic Stem Cells.
Tet proteins connect the O-linked N-acetylglucosamine transferase Ogt to chromatin in embryonic stem cells.
Specimen part
View SamplesThese are 6-ethylthioinosine-resistant and non-resistant Primary Effusion Lymphoma (PEL) subclones of the BC-3 cell line.
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Sex, Age, Specimen part, Disease, Disease stage, Cell line, Treatment, Race
View SamplesIn order to identify genes regulated by VE-cadherin expression, we compared a mouse VE-cadherin null cell line (VEC null) with the same line reconstituted with VE-cadherin wild type cDNA (VEC positive). The morphological and functional properties of these cell lines were described previously [Lampugnani,M.G. et al. Contact inhibition of VEGF-induced proliferation requires vascular endothelial cadherin, beta-catenin, and the phosphatase DEP-1/CD148. J. Cell Biol. 161, 793-804 (2003)]. By Affymetrix gene expression analysis we found several genes up-regulated by VE-cadherin, among which claudin-5 reached remarkably high levels. The up-regulation of these genes required not only VE-cadherin expression but also cell confluence suggesting that VE-cadherin clustering at junctions was needed.
Endothelial adherens junctions control tight junctions by VE-cadherin-mediated upregulation of claudin-5.
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