Blood Cancer Discovery最新文献

The influence of genetic ancestry on genomics in T-cell acute lymphoblastic leukemia (T-ALL) has not been fully explored. We examined the impact of genetic ancestry on multiomic alterations, survival outcomes, and risk stratification. Among 1,309 children and young adults with T-ALL treated on the Children's Oncology Group trial AALL0434, the prognostic value of five commonly altered T-ALL genes varied by ancestry-including NOTCH1, which was associated with superior overall survival for patients of European ancestry but was nonprognostic among patients of African ancestry. Integrating genetic ancestry with published T-ALL risk classifiers, we identified that an X01 penalized Cox regression classifier stratified patients regardless of ancestry, whereas a European multigene classifier misclassified patients of certain ancestries. Overall, 80% of patients harbored a genomic alteration in at least one gene with differential prognostic impact in an ancestry-specific manner. These data demonstrate the importance of incorporating genetic ancestry into genomic risk classification.

Significance: There is a lack of studies examining the prognostic significance of genomic features by genetic ancestry in T-ALL, especially in non-European ancestral groups. In this study, we demonstrate how the prognostic value of individual alterations differs by genetic ancestry, warranting future studies to identify germline alleles affecting these associations. See related commentary by de Smith, p. xxx.

Therapeutic targeting of acute myeloid leukemia (AML) is hampered by intra- and inter-tumoral cell state heterogeneity. To develop a more precise understanding of AML cell states, we constructed a reference atlas of human hematopoiesis from 263,159 single-cell transcriptomes spanning 55 cellular states. Using this atlas, we mapped more than 1.2 million cells spanning 318 leukemia samples, revealing 12 recurrent patterns of aberrant differentiation in AML. Notably, this uncovered unexpected AML cell states resembling lymphoid and erythroid progenitors that were prognostic within the clinically heterogeneous context of normal karyotype AML, independent of genomic classifications. Systematic mapping of genotype-to-phenotype associations revealed specific differentiation landscapes associated with more than 45 genetic drivers. Importantly, distinct cellular hierarchies can arise from samples sharing the same genetic driver, potentially reflecting distinct cellular origins for disease-sustaining leukemia stem cells. Thus, precise mapping of malignant cell states provides insights into leukemogenesis and refines disease classification in acute leukemia.

Significance: We present a single-cell reference atlas of human hematopoiesis and a computational tool for rapid mapping and classification of healthy and leukemic cells. Applied to AML, this has enabled single-cell analysis at the scale of hundreds of patient samples, revealing the full breadth of derailment of differentiation in AML. See related commentary by Berger and Penter, p. 280.

Clonal hematopoiesis of indeterminate potential (CHIP) has broad clinical relevance, and TP53 plays various roles within cells. However, the gene-specific and cross-disease significance of CHIP with TP53 mutations (TP53-CHIP) remains unclear. In this study, we evaluated TP53-CHIP using targeted sequencing data of 140,597 individuals without hematologic neoplasms in BioBank Japan. We identified 1,157 individuals with TP53-CHIP and clarified the characteristics of mutations and carriers. TP53-CHIP was associated with poor overall survival, especially because of lymphoid neoplasms and respiratory disease, in addition to myeloid neoplasms. Significant interactions accompanied by excess risks were observed between TP53-CHIP and lifestyle factors for disease-specific mortality: acetaldehyde exposure (resulting from the interaction between drinking and the germline variant of ALDH2) for myeloid neoplasms and smoking for respiratory disease. The clinical significance of TP53-CHIP was sometimes largely independent of variant allele fractions. These findings elucidate aspects of disease pathogenesis and inform personalized risk management.

Significance: TP53-CHIP contributed to a wide range of outcomes besides myeloid neoplasm mortality. TP53-CHIP, when combined with environmental factors, showed a remarkably higher risk for disease-specific mortality, accompanied by excess risks.

This commentary explores the concept and utility of studying oncogene co-expression at single-cell resolution and its clinical and biological implications. We emphasize the importance of scalable methods, mathematically driven quantification models, and artificial intelligence integration to enhance the clinical utility of this approach.

The genetic subtypes of Burkitt lymphoma have been defined, but the role of epigenetics remains to be comprehensively characterized. We searched genomic DNA from 218 patients across four continents for recurrent DNA methylation patterns and their associations with clinical and molecular features. We identified DNA methylation patterns that were not fully explained by the Epstein-Barr virus status or mutation status, leading to two epitypes described here as HypoBL and HyperBL. Each is characterized by distinct genomic and clinical features including global methylation, mutation burden, aberrant somatic hypermutation, and survival outcomes. Methylation, gene expression, and mutational differences between the epitypes support a model in which each arises from a distinct cell of origin. These results, pending validation in external cohorts, point to a refined risk assessment for patients with Burkitt lymphoma who may experience inferior outcomes.

Significance: Burkitt lymphoma can be divided into two epigenetic subtypes (epitypes), each carrying distinct biological, transcriptomic, genomic, and clinical features. Epitype is more strongly associated with clinical and mutational features than the Epstein-Barr virus status or genetic subtype, highlighting an important additional layer of Burkitt lymphoma pathogenesis.

In this issue of Blood Cancer Discovery, Varano and colleagues uncover a substantial fraction of high-grade B-cell lymphoma with MYC and BCL2(-BCL6) translocations (so called "double-hit" lymphomas or high-grade B-cell lymphoma-double-hit-BCL2) that lack detectable expression of the B-cell receptor. MYC translocation in these cells is mediated by RAG enzymes, induced in response to silencing of the B-cell receptor in a precursor cell, a feature that renders them resistant to polatuzumab vedotin. See related article by Varano et al., p. 364.

Despite the remarkable efficacy of targeted therapies and immunotherapies in B-cell acute lymphoblastic leukemia (B-ALL), relapsed and refractory cases remain a major challenge. In this review, we discuss how integrating targeted agents with immunotherapy could help overcome resistance and improve long-term patient outcomes in B-ALL.

This article presents a novel computational tool, "BoneMarrowMap," that enables the mapping of leukemic single-cell RNA sequencing datasets to hematopoietic differentiation states. By utilizing BoneMarrowMap for a large-scale single-cell RNA sequencing reanalysis, the authors discover 12 recurrent acute myeloid leukemia differentiation patterns linked to prognosis and treatment and dissect leukemic clonal architectures within individual patients. See related article by Zeng and colleagues, p. 307.

The B-cell receptor (BCR) is critical for mature B-cell lymphomas (BCL), serving as a therapeutic target. We show that high-grade BCLs with MYC and BCL2 rearrangements [HGBCL-double-hit (DH)-BCL2] predominantly exhibit immunoglobulin heavy (IGH) chain silencing, leading to BCR shutdown. IGH-silenced HGBCL-DH-BCL2 (IGHUND) tumors differ from IGH+ counterparts in germinal center (GC) zone programs, MYC expression, and immune infiltrate. Whereas IGH+ HGBCL-DH-BCL2 tumors favor IGM/IG-κ expression, IGHUND counterparts complete IGH isotype switching and IG-λ rearrangements. IGHUND lymphomas retain productive IGHV rearrangements and require IGH for optimal fitness. BCR silencing, caused by accelerated IGH turnover and reduced IGH expression, precedes HGBCL-DH-BCL2 onset, inducing RAG1/2-dependent IG light chain editing and facilitating t(8;22)/IGL::MYC translocations. IGHUND HGBCL-DH-BCL2 models exhibit reduced sensitivity to the CD79B-targeting antibody-drug conjugate polatuzumab vedotin. Collectively, HGBCL-DH-BCL2 commonly arises from isotype-switched t(14;18)+ GC B cells, which edit IG light chains, fueling intraclonal diversification, BCR extinction, and t(8;22) while maintaining IGH dependence, with clinical implications.

Significance: These findings link BCR silencing in IGH isotype-switched t(14;18)+ GC B cells to RAG1/2 expression, which triggers IG light chain editing and predisposes to IGL::MYC translocations, promoting HGBCL. In HGBCL with MYC and BCL2 rearrangements, BCR silencing protects from polatuzumab vedotin killing. See related commentary by Shevchenko and Hodson, p. 284.

Acute myeloid leukemia (AML) with complex karyotype is characterized by high genomic complexity, including frequent TP53 mutations and chromothripsis. Genomic rearrangements can reposition active enhancers near proto-oncogenes, leading to their aberrant expression; however, a comprehensive understanding of these events in AML is still incomplete. To facilitate the discovery of such "enhancer hijacking" events, we developed Pyjacker, a computational tool, and applied it to 39 AML samples with complex karyotype. Pyjacker identified several enhancer hijacking events in AML patient samples, including aberrant expression of MNX1, which can result from del(7)(q22q36) and is associated with hijacking of a CDK6 enhancer. MNX1 activation occurred in 1.4% of patients with AML and showed significant co-occurrence with BCOR mutations. Through a xenograft mouse model, we demonstrated that MNX1 is required for leukemia cell fitness. Pyjacker is an easy-to-use, accurate, and broadly applicable tool for identifying consequences of genomic events driving tumorigenesis, especially when germline genomic data are missing.

Significance: This study examines the consequences of structural alterations in AML and demonstrates that proto-oncogene activation by enhancer hijacking is an understudied pathomechanism. MNX1 overexpression demonstrates that deletions on chromosome 7q can not only lead to haploinsufficiency but also to activation of oncogenes by enhancer hijacking.