Aberrant BCAT1 expression augments mTOR activity and accelerates disease progression in Chronic Lymphocytic leukemia
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1001035 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:To identify genes contributing to the pathobiology of CLL, we performed gene expression profiling of mRNA/cDNA isolated from N=117 flow sorted CLL and detected aberrant expression of the metabolic enzyme branched chain amino acid transferase (BCAT1) in CLL with del17p/TP53mut. We performed immunoblotting in 205 and Q-PCR in 269 CLL samples and confirmed the highly preferential expression of BCAT1 in CLL with del17p/TP53mut (66%) or trisomy 12 (77%), and largely absent expression in CLL with del13q14 (15%) or normal FISH (29%). BCAT1 was not expressed in normal human lymph node derived B cells. The products of the bidirectional BCAT1 reaction, including leucine, acetyl-CoA, and alpha-ketoglutarate are activators of MTOR. We measured an ~2-fold higher MTOR activity via normalized p-S6K levels in CLL with BCAT1 high versus absent expression before and after sIgM crosslinking, which was abolished following pretreatment with a specific BCAT1 inhibitor. We performed steady state metabolomics and heavy isoptope metabolic tracing in primary CLL cells, demonstrating that CLL cells are avid consumers of branched chain aminoacids (BCAAs) and that BCAT1 in CLL engages in rapid bidirectional substrate utilization. Biologically, three CLL-derived cell lines with targeted disruption of BCAT1 had substantially reduced growth ex vivo. Further, CLL with aberrant BCAT1 expression were less sensitive to Venetoclax-induced apoptosis. Clinically, the expression of any BCAT1 protein in CLL resulted in shorter median survival than in CLL without BCAT1 expression (125 mo versus 296 mo; p<0.0001), even after exclusion of del17p/TP53mut cases (193 mo versus 296 mo; p<0.003).
2024-12-23 | GSE239832 | GEO
Project description:Protein synthesis and autophagic degradation are regulated in an opposite manner by mammalian target of rapamycin (mTOR), whereas under certain conditions it would be beneficial if they occured in unison to handle rapid protein turnover. We observed a distinct cellular compartment at the trans-side of the Golgi apparatus, the ‘TOR-autophagy spatial coupling compartment’ (TASCC), where (auto)lysosomes and mTOR accumulated during Ras-induced senescence. mTOR recruitment to the TASCC was amino acid- and Rag guanosine triphosphatase (GTPase)-dependent, and disruption of mTOR localization to the TASCC suppressed interleukin-6/8 synthesis. TASCC-formation was observed during macrophage differentiation and in glomerular podocytes; both displayed increased protein secretion. The spatial coupling of cells’ catabolic and anabolic machinery could augment their respective functions and facilitate the mass synthesis of secretory proteins. To compare gene expression profile between growing and oncogenic Ras induced senescence, 4OHT inducible ER:H-RasV12 was stably expressed in IMR90 human diploid fibroblasts. Total RNA was isolated from day 0 and day 4 after 4OHT addition. There were 3 biological replicates for each of day0 and day 4 timepoints.
2011-05-04 | E-GEOD-28464 | biostudies-arrayexpress
Project description:Previously, we have identified cytosolic form of the branched chain amino-acid transaminase 1 (BCAT1) as notably hypomethylated in low-malignant potential (LMP) and high-grade (HG) serous epithelial ovarian tumors, compared to normal ovarian tissues. Here we show that BCAT1 is strongly overexpressed in both LMP and HG serous EOC tumors, thus suggesting that epigenetic mechanisms might be implicated in BCAT1 overexpression in serous epithelial ovarian cancer (EOC). Knockdown of the BCAT1 expression in EOC cells led to sharp decrease of cell proliferation and induced S-phase cell cycle arrest. Additionally, BCAT1 suppression significantly inhibited EOC cell migration and invasion. Gene expression profiling and consecutive network and pathway analyses confirmed these findings, as numerous genes and pathways known previously to be implicated in ovarian tumorigenesis, including EOC tumor invasion and metastasis, were found to be downregulated upon BCAT1 suppression, while some tumor suppressor genes were induced. Taken together, our data are indicative for a strong oncogenic potential of the BCAT1 gene in advanced EOC and identify this transaminase as a novel EOC biomarker and putative EOC therapeutic target.
2015-10-01 | GSE64424 | GEO
Project description:To investigate the mechanism of BCAT1 in mediating resistance to third-generation EGFR-TKI, we employed RNA-seq analysis to compare the transcriptome signature of ASK120067-resistant NSCLC cells with or without BCAT1 knockdown. Here, gene set enrichment (GSEA) revealed a significant decrease in the expression of genes in glycolysis pathway following small interfering RNA (siRNA)-mediated BCAT1 knockdown, which indicated the role for BCAT1 in supporting TKI resistance through upregulation of glycolysis.
2024-08-15 | GSE247584 | GEO
Project description:In this report, we revealed that branched chain amino acid transaminase 1 (BCAT1) is highly enriched in both mouse and human TKI-resistant CML cells. Leukemia was almost completely abrogated upon BCAT1 knockdown during transplantation in a BCR-ABLT315I-induced murine TKI-resistant CML model . Moreover, knockdown of BCAT1 led to a dramatic decrease in the proliferation of TKI-resistant human leukemia cell lines. BCAA/BCAT1 signaling enhanced the phosphorylation of CREB, which is required for maintenance of TKI-resistant CML cells. Importantly, blockade of BCAA/BCAT1 signaling efficiently inhibited leukemogenesis both in vivo and in vitro.
2024-05-30 | GSE262421 | GEO
Project description:Glioblastoma is the most common malignant brain tumor in adults. Cellular plasticity and the poorly differentiated features result in a fast relapse of the tumors following treatment. Moreover, the immunosuppressive microenvironment proved to be a major obstacle to immunotherapeutic approaches. Branched-chain amino acid transaminase 1 (BCAT1) is a metabolic enzyme that converts branched-chain amino acids into branched-chain keto acids, depleting cellular α-ketoglutarate and producing glutamate. BCAT1 was shown to drive the growth of glioblastoma and other cancers; however, its oncogenic mechanism remains poorly understood. Here, we show that BCAT1 is crucial for maintaining the poorly differentiated state of glioblastoma cells and that its low expression correlates with a more differentiated glioblastoma phenotype. Furthermore, orthotopic tumor injection into immunocompetent mice demonstrated that the brain microenvironment is sufficient to induce differentiation of Bcat1-KO tumors in vivo. We link the transition to a differentiated cell state to the increased activity of TET demethylases and the hypomethylation and activation of neuronal differentiation genes. In addition, the knockout of Bcat1 attenuated immunosuppression, allowing for an extensive infiltration of CD8 + cytotoxic T-cells and complete abrogation of tumor growth. Further analysis in immunodeficient mice revealed that both tumor cell differentiation and immunomodulation following BCAT1-KO contribute to the long-term suppression of tumor growth. In summary, our study unveils BCAT1's pivotal role in promoting glioblastoma growth by inhibiting tumor cell differentiation and sustaining an immunosuppressive milieu. These findings offer a novel therapeutic avenue for targeting glioblastoma through the inhibition of BCAT1.
2024-11-08 | GSE247299 | GEO
Project description:Protein synthesis and autophagic degradation are regulated in an opposite manner by mammalian target of rapamycin (mTOR), whereas under certain conditions it would be beneficial if they occured in unison to handle rapid protein turnover. We observed a distinct cellular compartment at the trans-side of the Golgi apparatus, the ‘TOR-autophagy spatial coupling compartment’ (TASCC), where (auto)lysosomes and mTOR accumulated during Ras-induced senescence. mTOR recruitment to the TASCC was amino acid- and Rag guanosine triphosphatase (GTPase)-dependent, and disruption of mTOR localization to the TASCC suppressed interleukin-6/8 synthesis. TASCC-formation was observed during macrophage differentiation and in glomerular podocytes; both displayed increased protein secretion. The spatial coupling of cells’ catabolic and anabolic machinery could augment their respective functions and facilitate the mass synthesis of secretory proteins.
2011-05-05 | GSE28464 | GEO
Project description:To identify the potential interaction protein that interacts with BCAT1 by IP-MS, we established the stable cell line with vector and BCAT1 in AGS. Then ten million cells were collected lysed in ice-cold 0.1% NP-40 buffer (50 mM Na2HPO4, pH 7.5, 150 mM NaCl) with protease inhibitors cocktail (Sigma, p8340). The supernatants were collected by centrifugation and incubated with 10 µL Anti Flag‐beads (Sigma, A2220at 4°C for overnight. After incubation, beads were washed with lysis buffer for 3 times. Precipitates were resuspended in 1 × SDS loading buffer and separated by SDS-PAGE (polyacrylamide gel electrophoresis). Then cut off (about 1cm2) gel for trypsin hydrolysis and collected and dried the peptide for MS analysis (Thermo Fisher Q Exactive).
2024-11-15 | PXD041556 | Pride
Project description:High levels of branched-chain amino acid (BCAA) transaminase 1 (Bcat1) have been associated with adverse prognosis and drug resistance in several cancer types. However, the mechanistic role of Bcat1 in T-cell acute lymphoblastic leukemia (T-ALL) development is ill defined. Here, we used a mouse T-ALL model to show that Bcat1 is required for T-ALL development and maintenance. Using a NOTCH1 gain-of-function retroviral model of T-ALL, mouse cells genetically deficient for Bcat1 showed defects in developing leukemia. Amongst the pathways upregulated in Bcat1 KO delta E-NOTCH1 cells we found “DNA repair”, “apoptosis”, and “p53 pathway”. We thus hypothesize that Bcat1 may be implicated in cell cycle progression or apoptosis of T-ALL cells.
2024-09-01 | GSE267966 | GEO