Pediatric B-cell precursor acute lymphoblastic leukemia samples with very early relapse
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ABSTRACT:
PROVIDER: EGAS00001005615 | EGA |
REPOSITORIES: EGA
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Project description:Relapse is the most common cause of treatment failure in pediatric acute lymphoblastic leukemia (ALL) and is often difficult to predict. To explore the prognostic impact of recurrent DNA copy number abnormalities on relapse, we performed high-resolution genomic profiling of 34 paired diagnosis-relapse ALL samples. Recurrent lesions detected at diagnosis, including PAX5, CDKN2A, and EBF1, were frequently absent at relapse, indicating that they represent secondary events that may be absent in the relapse-prone therapy-resistant progenitor cell. In contrast, deletions and nonsense mutations in IKZF1 (IKAROS), were highly enriched and consistently preserved at the time of relapse. A targeted copy number screen in an unselected cohort of 131 precursor B-ALL cases, enrolled in the dexamethasone-based Dutch Childhood Oncology Group treatment protocol ALL9, revealed that IKZF1 deletions are significantly associated with poor relapse-free and overall survival rates. Separate analysis of ALL9-treatment subgroups revealed that non-high-risk patients with IKZF1 deletions exhibited a ~12-fold higher relative relapse rate than those without IKZF1 deletions. Consequently, IKZF1 deletion status allowed the prospective identification of 53% of the relapse-prone non-high-risk-classified patients within this subgroup and, therefore, serves as one of the strongest predictors of relapse at the time of diagnosis with high potential for future risk stratification. Affymetrix NspI 250k array data of 34 paired diagnosis and relapse samples of pediatric ALL. From 13 patients a complete remission sample was available. Four cases had 2 relapses.
2010-03-01 | GSE20353 | GEO
Project description:Early T-cell precursor acute lymphoblastic leukemia (ETP-ALL) develops from very early cells with the potential for both T-cell and myeloid differentiation. The ambiguous nature of leukemic blasts in ETP-ALL may lead to immunophenotypic alterations at relapse. Here, we address immunophenotypic alterations and related classification issues, as well as genetic features of relapsed pediatric ETP-ALL. RNAseq was performed with the primary goal of crypric gene fusions search within subcohorts of relapsed and non-relapsed patients with sufficient material available. Overall, 3 relapsed and 8 non-relapsed patients were tested. As a relsult, 1 relasped and 3 non-relapsed patients were found to carry leukemia-specific fusions, of those 3 were confurmed by FISH (2 cases of ETV6 rearrangements and one PICALM::MLLT10-positive case) while only one cryptic rearrangement was caught in a non-relapsed patient (BCL11B cryptic rearrangement negative by FISH). Other 7 patients were not found to carry any leukemia-specisic fusions.
2024-06-01 | GSE266550 | GEO
Project description:Purpose: In childhood acute lymphoblastic leukemia (ALL), approximately 25% of patients suffer from relapse. In recurrent disease, despite intensified therapy, overall cure rates of 40% remain unsatisfactory and survival rates are particularly poor in certain subgroups. The probability of long-term survival after relapse is predicted from well-established prognostic factors, i. e. time and site of relapse, immunophenotype and minimal residual disease. However, the underlying biological determinants of these prognostic factors remain poorly understood. Results: We show here that patients with very early relapse of ALL are characterized by a distinctive gene expression pattern. We identified a set of 83 genes differentially expressed in very early relapsed ALL compared to late relapsed disease. The vast majority of genes was up-regulated and many were late cell cycle genes with a function in mitosis. In addition, samples from patients with very early relapse showed a significant increase in the percentage of S and G/2M phase cells and this correlated well with the expression level of cell cycle genes. Conclusions: Very early relapse of ALL is characterized by an increased proliferative capacity of leukemic blasts and up-regulated mitotic genes. The latter suggests that novel drugs, targeting late cell cycle proteins, might be beneficial for these patients that typically face a dismal prognosis. Keywords: disease state analysis
2006-09-27 | GSE4698 | GEO
Project description:Purpose: In childhood acute lymphoblastic leukemia (ALL), approximately 25% of patients suffer from relapse. In recurrent disease, despite intensified therapy, overall cure rates of 40% remain unsatisfactory and survival rates are particularly poor in certain subgroups. The probability of long-term survival after relapse is predicted from well-established prognostic factors, i. e. time and site of relapse, immunophenotype and minimal residual disease. However, the underlying biological determinants of these prognostic factors remain poorly understood. Results: We show here that patients with very early relapse of ALL are characterized by a distinctive gene expression pattern. We identified a set of 83 genes differentially expressed in very early relapsed ALL compared to late relapsed disease. The vast majority of genes was up-regulated and many were late cell cycle genes with a function in mitosis. In addition, samples from patients with very early relapse showed a significant increase in the percentage of S and G/2M phase cells and this correlated well with the expression level of cell cycle genes. Conclusions: Very early relapse of ALL is characterized by an increased proliferative capacity of leukemic blasts and up-regulated mitotic genes. The latter suggests that novel drugs, targeting late cell cycle proteins, might be beneficial for these patients that typically face a dismal prognosis. Experiment Overall Design: We performed gene expression profiling on 60 prospectively collected samples of children with first relapse of acute lymphoblastic leukemia enrolled on the relapse trial ALL-REZ BFM 2002 of the Berlin-Frankfurt-Muenster study group.
2008-06-13 | E-GEOD-4698 | biostudies-arrayexpress
Project description:There is a distinct signature of differentially expressed probes from diagnosis to relapse Gene expression profiles of pediatric patients with B-precursor ALL were compared to at 2 time points, diagnosis and relapse. The overall design was a comparison of gene expression at diagnosis and relapse within individual patients. A subset analysis (comparing diagnosis to relapse expression within individuals), was done for early relapse (less than 36 months) cases only and late relapse (greater than 36 months) cases only.
2011-09-23 | E-GEOD-28460 | biostudies-arrayexpress
Project description:Despite high survival rates in pediatric acute lymphoblastic leukemia (ALL), relapse remains a leading cause of cancer-related death in children. Many patients suffer from adverse drug effects during treatment and other complications later in life, and would benefit from improved relapse prediction at diagnosis. We performed whole genome sequencing of samples collected at diagnosis, relapse(s) and remission from 29 Nordic patients with pediatric ALL. Somatic mutations were called using individually matched remission samples as controls, and allelic expression of the mutations in the ALL cells was assessed using RNA-sequencing. These analyses identified 29 previously known ALL driver genes, of which nine genes carried recurrent protein-coding mutations in our sample set, and 20 mutated driver genes occurred in individual samples. We detected putative non-coding mutations in regulatory regions of seven additional genes that have not been described previously in ALL. We observed an increased burden of somatic mutations at relapse. Cluster analysis of hundreds of somatic mutations per sample revealed three distinct evolutionary trajectories during ALL progression. In an “ancestral clone trajectory”, the major cell clone at relapse originated from a founder clone that was not detectable at diagnosis. In a “rising diagnostic clone trajectory”, a minor cell clone at diagnosis expanded to form the major cell clone at relapse. In a “persistent diagnostic clone trajectory”, the major cell clone at diagnosis persisted during treatment until relapse. The evolutionary trajectories provide insight into the mutational mechanisms leading relapse in ALL and could offer biomarkers for improved risk prediction in individual patients.
2021-08-11 | GSE163634 | GEO
Project description:Relapse samples have high methylation level than dianosis samples Promoter mehtylation level was measured and compared between relapse and diagnosis samples
2011-09-22 | E-GEOD-28461 | biostudies-arrayexpress
Project description:To understand the development of new psoriasis lesions, we studied a group of moderate-to-severe psoriasis patients who experienced a relapse after ceasing efalizumab (anti-CD11a, Raptiva, Genentech). There were increased CD3+ T cells, neutrophils, CD11c+ and CD83+ myeloid DCs, but no increase in CD1c+ resident myeloid DCs. In relapsed lesions, there were many CD11c+CD1c-, inflammatory myeloid DCs identified by TNFSF10/TRAIL, TNF, and iNOS. CD11c+ cells in relapsed lesions co-expressed CD14 and CD16 in situ. Efalizumab induced an improvement in many psoriasis genes, and during relapse, the majority of these genes reversed back to a lesional state. Gene Set Enrichment Analysis (GSEA) of the transcriptome of relapsed tissue showed that many of the gene sets known to be present in psoriasis were also highly enriched in relapse. Hence, on ceasing efalizumab, T cells and myeloid cells rapidly enter the skin to cause classic psoriasis. To determine the transcsriptome of skin samples in 4 responding patients who relapsed after receiving efalizumab for treatment of psoriasis, using paired baseline non-lesional (NL, n=2); lesional (LS, n=4);week 12 post-treatment (week 12, n=4), and relapse (n=4). Comparison of mean gene expression of each group at baseline, and considering treatment effect
2012-01-30 | E-GEOD-30768 | biostudies-arrayexpress
Project description:Relapse of acute myeloid leukemia (AML) is highly aggressive and often treatment refractory. We analyzed previously published AML relapse cohorts and found that 40% of relapses occur without changes in driver mutations, suggesting that non-genetic mechanisms drive relapse in a large proportion of cases. We therefore characterized epigenetic patterns of AML relapse using 26 matched diagnosis-relapse samples with ATAC-seq. This analysis identified a relapse-specific chromatin accessibility signature for mutationally stable AML, suggesting that AML undergoes epigenetic evolution at relapse independent of mutational changes. Analysis of leukemia stem cell (LSC) chromatin changes at relapse indicated that this leukemic compartment underwent significantly less epigenetic evolution than non-LSCs, while epigenetic changes in non-LSCs reflected overall evolution of the bulk leukemia. Finally, we used single-cell ATAC-seq paired with mitochondrial sequencing (mtscATAC) to map clones from diagnosis into relapse along with their epigenetic features. We found that distinct mitochondrially-defined clones exhibit more similar chromatin accessibility at relapse relative to diagnosis, demonstrating convergent epigenetic evolution in relapsed AML. These results demonstrate that epigenetic evolution is a feature of relapsed AML and that convergent epigenetic evolution can occur following treatment with induction chemotherapy.
2024-04-17 | GSE256495 | GEO
Project description:There is a distinct signature of differentially expressed probes from diagnosis to relapse
2011-09-23 | GSE28460 | GEO