Similar Datasets
Project description:Germinal centre (GC) B cells proliferate at some of the highest rates of any mammalian cell. Yet the metabolic processes which enable this are poorly understood. We performed integrated metabolomic and transcriptomic profiling of GC B cells, and found that asparagine metabolism is highly upregulated. Asparagine is conditionally essential to B cells, and its synthetic enzyme, asparagine synthetase (ASNS) is markedly upregulated following their activation, through the integrated stress response sensor general control non-derepressible 2 (GCN2). When Asns is deleted, B cell survival in low asparagine conditions is severely impaired. Using stable isotope tracing, we found that metabolic adaptation to the absence of asparagine requires ASNS, and that the synthesis of nucleotides is particularly sensitive to asparagine deprivation. Conditional deletion of Asns in B cells selectively impairs GC formation, associated with a reduction in RNA synthesis rates. Finally, removal of environmental asparagine by asparaginase was found to also severely compromise the GC reaction.
2024-04-03 | GSE228845 | GEO
Project description:Asparagine availability controlsgerminal centre B cell homeostasis
| PRJNA951723 | ENA
Project description:Asparagine availability controls B cell homeostasis
| PRJNA1161789 | ENA
Project description:Molecular effects of ISRIB during asparagine deprivation
| PRJNA521363 | ENA
Project description:Single - cell profiling of patient tumours and of mouse models is revealing that many cancers are constituted of communities of genetically and phenotypically distinct clonal lineages 1 - 12. A functional model of breast cancer heterogeneity revealed that clonal sub - populations proficient at generating circulating tumour cells were not equally capable of forming metastases at secondary sites 13. A combination of differential expression and focused in vitro and in vivo RNAi screens revealed candidate drivers of metastasis discriminating these clones, which were then evaluated in gene expression datasets from breast cancer patients. Among these, Asparagine Synthetase (Asns) expression in a patient's primary tumour was most strongly correlated with later metastatic relapse. Silencing of Asns reduced both metastatic potential in vivo and invasive potential in vitro. Conversely, increasing the availability of extracellular asparagine increased the invasive potential of mouse and human breast cancer cells, and enforced Asns expression promoted metastasis. Decreasing asparagine availability in mice by treatment with L-asparaginase or even by dietary restriction strongly reduced metastasis from orthotopic tumours. Asparagine availability varies betwe en tissues, potentially explaining selective effects on particular steps of tumor progression. Asparagine limitation reduced the production of proteins that promote the epithelial to mesenchymal transition, providing one potential mechanism for how the availability of a single amino acid could regulate metastatic progression.
2018-02-08 | GSE107109 | GEO
Project description:Asparagine deprivation by L-Asparaginase is a successful therapeutic strategy in Acute Lymphoblastic Leukemia, with resistance occurring due to upregulation of ASNS. L-Asparaginase efficacy in solid tumors is hampered by dose-related toxicities. Large scale loss of function genetic screens identified ASNS, the only human enzyme synthetizing asparagine, as a cancer dependency in several solid malignancies, including melanoma. We here evaluate the therapeutic potential of targeting ASNS in melanoma cells in-vitro and in-vivo. Using ex-vivo quantitative proteome and transcriptome profiling, we observed that concomitant ASNS deletion and asparagine deprivation elicit a compensatory mechanism allowing tumor growth. Genome wide CRISPR screens upon manipulation of aminoacid levels identifies MAPK and GCN2 as critical nodes mediating the observed resistance mechanism. Importantly MEK and GCN2 inhibitor synergize with L-Asparaginase suggesting novel potential therapeutic strategy in melanoma.
2022-02-15 | PXD015152 | Pride
Project description:Asparagine-linked glycosylation (N-glycosylation), a fundamental modification of proteins synthesized in the endoplasmic reticulum, is easily suppressed by glucose deprivation, but the role of this metabolic link has long remained unclear. We previously identified the activity of mannose metabolism, which branches from glycolysis, as a key determinant for N-glycosylation efficiency in glucose deprivation. Our genetic approach to uncouple mannose metabolism from glycolysis allowed the precise control of mannose metabolic activity via its salvage pathway, revealing that moderate decrease in N-glycosylation efficiency activated the pro-survival PERK-eIF2 signals, which enabled cells to safely cut metabolic costs in N-glycosylation to the minimal levels required for cell survival. In contrast, severe decrease in N-glycosylation efficiency sensitized lysosomes to external insults, thereby biasing cell fates to cell death. Moreover, we demonstrated the specific role of glucose metabolism in regulating global translation efficiency via LKB1. Our study reveals the unexpected role of N-glycosylation as a glucose-sensing mechanism.
2026-03-02 | PXD066382 | Pride
Project description:Asparagine availability governs metastasis in a model of breast cancer
| PRJNA419005 | ENA
Project description:Sex-related differences in asparagine metabolism are associated with cancer prognosis. However, the effect of exogenous asparagine on colorectal cancer (CRC) growth in men and women remain unclear. This study aims to understand the relationship between exogenous asparagine supplementation and 17β-estradiol levels and to elucidate mechanisms underlying sex-dependent signaling during CRC development. We administered asparagine intraperitoneally to tumor-bearing immunodeficient male and female Rag2/Il2RG (R2G2) mice. Asparagine supplementation caused a significant increase in tumor asparagine levels in both the tumor-bearing male and female R2G2 mice but increased serum estradiol levels and suppressed tumor growth in female R2G2 mice only. Additionally, we combined transcriptome, metabolome and immunochemical analyses and found that intraperitoneal asparagine treatment induced sex-dependent intra-tumoral metabolic changes to asparagine, aspartate, glutamine and glutamate levels in CRC cells. We observed that in females, exogenous asparagine exerts a negative feed-back effect on de novo asparagine synthesis and is associated with the activation of a sub-population of macrophages that may secrete 17β-estradiol via an aromatase or cytochrome P450 family 19 (CYP19)-dependent mechanism, resulting in improved tumor-specific survival. Conversely, in male mice, asparagine treatment augments tumor growth and is related to decreased numbers of macrophages, reduction in CYP19-mediated 17β-estradiol secretion leading to worsened tumor-specific survival. Overall, our results reveal a novel and sex-specific role for exogenous asparagine during cancer progression and underscores the importance of understanding mechanisms that control asparagine biosynthesis.
2025-12-23 | GSE314476 | GEO