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.We determined the effects of BCAT1 depletion on cellular sensitivity to DNA damaging agents (etoposide).
Project description:Acute lymphoblastic leukemia (ALL) is the most common childhood cancer, and it has a 5-year survival rate of 85% for European children. But for subsets of patients who fail to respond to standard of care chemotherapeutics, treatment options are limited, and clinical prognosis is poor. To establish a platform and methodology to better characterize ALL subtypes and identify their pharmacologic vulnerabilities, we assembled a biobank of 49 readily available childhood ALL cell lines representing diverse immunotypes and genetic profiles. Using these cell lines, we performed comprehensive multi-omic analyses, providing proteomic, transcriptomic and pharmacoproteomic characterization of childhood ALL. We used this resource to characterize the functional impact of genetic fusions and cellular differentiation states on the proteome. Additionally, we identified a novel drug vulnerability in one of the ALL subtypes. Our results are provided as an interactive online data portal with navigable proteomics, transcriptomics, and drug sensitivity profiles.
Project description:Cellular drug resistance is associated with an unfavorable prognosis in pediatric acute lymphoblastic leukemia (ALL). To identify genes conferring resistance to antileukemic agents, we analyzed the expression of >12,700 genes in sensitive and resistant ALL cells obtained at diagnosis from 174 patients. This revealed 42, 59, 54 and 22 genes (P≤0.001) that were differentially expressed in B-lineage ALL that was sensitive versus resistant to prednisolone, vincristine, asparaginase or daunorubicin, respectively, with prediction accuracies of 71-76%. Notably, 149 of the discriminating genes have not been previously associated with resistance to these anticancer agents. These included carbohydrate-metabolism and transcription-associated genes for prednisolone, cytoskeleton and extracellular matrix genes for vincristine, ribosomal protein and translation-associated genes for asparaginase, and RAS signaling and nucleosome remodeling complex genes for daunorubicin. The identification of novel genomic determinants of cellular drug resistance provides new insights for overcoming drug resistance in acute lymphoblastic leukemia. Keywords = ALL Keywords: other
Project description:Proteogenomic analysis and genomic profiling, RNA-sequencing, and mass spectrometry-based analysis of High hyperdiploid childhood acute lymphoblastic leukemia.
Project description:Proteogenomic analysis and genomic profiling, RNA-sequencing, and mass spectrometry-based analysis of High hyperdiploid childhood acute lymphoblastic leukemia.
Project description:Epigenetic modifications are dynamic and reversible, making them attractive targets for therapeutic intervention in cancer. Although several epigenetic drugs (epidrugs) have been clinically approved, their application in T-cell acute lymphoblastic leukemia (T-ALL) remains limited, and predictive biomarkers of response are lacking. Here, we present a mass spectrometry (MS)-based pharmacoepigenetic approach to profile histone post-translational modifications (hPTMs) to identify signatures associated with epidrug sensitivity in T-ALL. Baseline hPTM landscapes were previously established by our group for 21 T-ALL cell lines using liquid chromatography–tandem mass spectrometry (LC–MS/MS). Here, we treated these cell lines with a panel of nine epidrugs including anthracyclines, histone deacetylase inhibitors, and DNA methyltransferase inhibitors. Correlation of cell viability data with hPTM levels revealed distinct hPTM signatures linked to sensitivity for each drug class. These signatures were subsequently evaluated in T-ALL patient-derived xenograft (PDX) models. However, we our analysis revealed substantial discepancies in hPTM sensitivity signatures compared to those observed in vitro. Co-variation network analysis highlighted divergence in hPTM-hPTM correlation between the two models, underscoring limitations of cell lines for modeling dynamic epigenetic regulation in vivo. Our findings establish a framework for MS-based hPTM profiling in T-ALL and emphasize the importance of model selection in developing predictive epigenetic biomarkers.
Project description:The efficacy of glucocorticoid receptor modulation is well established in Acute Lymphoblastic Leukemia(ALL) but the response remains heterogeneous and limited by emergence of drug resistance. Here we use, two clonally-derived cell lines (CEM-C1 and CEM-C7) from a 3-year-old T-cell ALL patient, as a model system to understand the mechanisms of drug resistance in these cell lines; the clone CEM-C1 is resistant to dexamethasone-induced apoptosis and CEM-C7 is sensitive. We performed ATACseq and RNAseq to query for TF binding motifs present in the open regions of the chromatin and expression levels of TFs that could recognize the identified motifs. We are experimentally validating our hypothesis that depletion of the TFs identified, either singly or in combination, in CEM-C7 cells will cause dexamethasone resistance in CEM-C7 cells.
Project description:The development of a clinically relevant xenograft model of pediatric acute lymphoblastic leukemia, using a 4-drug treatment regimen designed to mimic pediatric remission induction therapy. Relapse and acquired drug resistance in T-cell acute lymphoblastic leukemia (T-ALL) remains a significant clinical problem. This study was designed to establish a preclinical model of resistance to induction therapy in childhood T-ALL to examine the emergence of drug resistance and identify novel therapies. We performed transcription profiling by array of human CD45-positive human lymphocytes from patients with acute pediatric lymphoblastic leukemia, and from xenografted NOD/SCID mice treated with vincristine, daunorubicin, dexamethasone and L-asparagine. Several different treatment regimes were used in this study (VLXD, VLXDR, VLXD2, VXL and VLXD2-ALL31) and are summarised in the protocols associated with this submission.
Project description:MicroRNA-sequencing of the bone marrow samples from Brazilian pediatric patients with B-cell acute lymphoblastic leukemia (B-ALL) and T-cell acute lymphoblastic leukemia (T-ALL).