scholarly journals A convergent malignant phenotype in B-cell acute lymphoblastic leukemia involving the splicing factor SRRM1

Author(s):  
Adria Closa ◽  
Marina Reixachs-Solé ◽  
Antonio Fuentes-Fayos ◽  
Katharina Hayer ◽  
Juan Melero ◽  
...  

Abstract A significant proportion of B-cell acute lymphoblastic leukemia (B-ALL) patients remains with a dismal prognosis due to yet undetermined mechanisms. We performed a comprehensive multicohort analysis of gene fusions, gene expression, and RNA splicing alterations to uncover molecular signatures potentially linked to the observed poor outcome. We identified 84 fusions with significant allele frequency across patients. We identified an expression signature that predicts high risk independently of the gene fusion background. This signature includes the upregulation of the splicing factor SRRM1, which potentially impacts splicing events associated with poor outcomes through protein-protein interactions with other splicing factors. Experiments in B-ALL cell lines provided further evidence for the role of SRRM1 on cell survival, proliferation, and invasion. Our findings reveal a convergent mechanism of aberrant RNA processing that sustains a malignant phenotype independently of gene fusions and could complement current clinical strategies in B-ALL.

2021 ◽  
Author(s):  
Adria Closa ◽  
Marina Reixachs-Sole ◽  
Antonio C Fuentes-Fayos ◽  
Katharina E Hayer ◽  
Juan L Melero ◽  
...  

A significant proportion of B-cell acute lymphoblastic leukemia (B-ALL) patients remains with a dismal prognosis due to yet undetermined mechanisms. We performed a comprehensive multicohort analysis of gene fusions, gene expression, and RNA splicing alterations to uncover molecular signatures potentially linked to the observed poor outcome. We identified 84 fusions with significant allele frequency across patients. We identified an expression signature that predicts high risk independently of the gene fusion background. This signature includes the upregulation of the splicing factor SRRM1, which potentially impacts splicing events associated with poor outcomes through protein-protein interactions with other splicing factors. Experiments in B-ALL cell lines provided further evidence for the role of SRRM1 on cell survival, proliferation, and invasion. Our findings reveal a convergent mechanism of aberrant RNA processing that sustains a malignant phenotype independently of gene fusions and could complement current clinical strategies in B-ALL.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Chao Gao ◽  
Shu-Guang Liu ◽  
Zhi-Xia Yue ◽  
Yi Liu ◽  
Jing Liang ◽  
...  

Abstract Background Although leukemic blast cells of Pro-B cell acute lymphoblastic leukemia (ALL) are arrested at the same stage of B cell differentiation, the immature B cell subtype is still biologically heterogeneous and is associated with diverse outcomes. This study aimed to explore the clinical-biological characteristics of pediatric pro-B ALL and factors associated with outcomes. Methods This study enrolled 121 pediatric patients aged 6 months to 14 years with newly diagnosed CD19+CD10− pro-B cell acute lymphoblastic leukemia (pro-B ALL) treated at Beijing Children’s Hospital from March 2003 to October 2018. Genetic abnormalities, immunophenotypic markers, minimal residual disease (MRD) at early treatment stage and long-term outcomes of children treated on two consecutive protocols were analyzed. Results KMT2A rearrangements were the most frequent abnormalities (incidence rate 33.06%), and were associated with lower frequency of CD13, CD33, CD22 and CD34 expression and higher frequency of CD7 and NG2 expression. Higher frequency of CD15 and CD133 expression was found in KMT2A-AFF1+ patients, exclusively. Presence of CD15 and absence of CD34 at diagnosis correlated with the high burden of MRD at the early stage of treatment. Outcomes were more favorable in patients older than 1 year, with absence of CD20 expression and KMT2A rearrangements, and with MRD lower than 1% at the end of induction and 0.1% before consolidation. Increased intensity of chemotherapy based on MRD analysis did not improve outcomes significantly (5-year EFS 73.9 ± 6.5% for BCH-2003 and 76.1 ± 5.3% for CCLG-2008, P = 0.975). Independent adverse prognostic factors were MRD ≥ 0.1% before consolidation and presence of KMT2A gene rearrangements (odds ratios [ORs] 9.424 [95% confidence interval (CI) 3.210, 27.662; P < 0.001]; 4.142 [1.535, 11.715, P = 0.005]; respectively). Conclusions Pediatric pro-B ALL is a heterogeneous disease. Genetic analysis and MRD evaluation can predict patients with dismal prognosis; however, intensive chemotherapy alone does not improve outcomes of these patients and targeted therapy or hematopoietic stem cell transplantation may be required.


2021 ◽  
Author(s):  
Eleonora Khabirova ◽  
Laura Jardine ◽  
Tim Coorens ◽  
Simone Webb ◽  
Taryn Treger ◽  
...  

Infant B-cell acute lymphoblastic leukemia (B-ALL) has not followed the increasing trend towards cure seen in other childhood B-ALLs. The prognosis for infants with KMT2A gene fusions is especially poor, and the origins of this aggressive leukemia remain unknown. Here, we investigated the developmental state of KMT2A-rearranged infant B-ALL within hematopoietic hierarchies of human fetal bone marrow, using bulk mRNA meta-analysis of childhood leukemia and examination of single lymphoblast transcriptomes. KMT2A-rearranged infant B-ALL was uniquely dominated by an early lymphocyte precursor (ELP) state. Direct comparison of infant lymphoblasts with ELP cells distilled the core oncogenic transcriptome of cancer cells which harboured potentially targetable hybrid myeloid-lymphoid features. Overall our quantitative molecular analyses demonstrate a distinct developmental state of KMT2A-rearranged infant B-ALL.


Hematology ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 9-15
Author(s):  
Run-Qing Lu ◽  
Li-Xin Wu ◽  
Jing Zhang ◽  
Ya-Zhen Qin ◽  
Yan-Rong Liu ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Stephanie L. Rellick ◽  
Gangqing Hu ◽  
Debra Piktel ◽  
Karen H. Martin ◽  
Werner J. Geldenhuys ◽  
...  

AbstractB-cell acute lymphoblastic leukemia (ALL) is characterized by accumulation of immature hematopoietic cells in the bone marrow, a well-established sanctuary site for leukemic cell survival during treatment. While standard of care treatment results in remission in most patients, a small population of patients will relapse, due to the presence of minimal residual disease (MRD) consisting of dormant, chemotherapy-resistant tumor cells. To interrogate this clinically relevant population of treatment refractory cells, we developed an in vitro cell model in which human ALL cells are grown in co-culture with human derived bone marrow stromal cells or osteoblasts. Within this co-culture, tumor cells are found in suspension, lightly attached to the top of the adherent cells, or buried under the adherent cells in a population that is phase dim (PD) by light microscopy. PD cells are dormant and chemotherapy-resistant, consistent with the population of cells that underlies MRD. In the current study, we characterized the transcriptional signature of PD cells by RNA-Seq, and these data were compared to a published expression data set derived from human MRD B-cell ALL patients. Our comparative analyses revealed that the PD cell population is markedly similar to the MRD expression patterns from the primary cells isolated from patients. We further identified genes and key signaling pathways that are common between the PD tumor cells from co-culture and patient derived MRD cells as potential therapeutic targets for future studies.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Asmaa M. Zahran ◽  
Azza Shibl ◽  
Amal Rayan ◽  
Mohamed Alaa Eldeen Hassan Mohamed ◽  
Amira M. M. Osman ◽  
...  

AbstractOur study aimed to evaluate the levels of MDSCs and Tregs in pediatric B-cell acute lymphoblastic leukemia (B-ALL), their relation to patients’ clinical and laboratory features, and the impact of these cells on the induction response. This study included 31 pediatric B-ALL patients and 27 healthy controls. All patients were treated according to the protocols of the modified St. Jude Children’s Research Hospital total therapy study XIIIB for ALL. Levels of MDSCs and Tregs were analyzed using flow cytometry. We observed a reduction in the levels of CD4 + T-cells and an increase in both the polymorphonuclear MDSCs (PMN-MDSCs) and Tregs. The frequencies of PMN-MDSCs and Tregs were directly related to the levels of peripheral and bone marrow blast cells and CD34 + cells. Complete postinduction remission was associated with reduced percentages of PMN-MDSCs and Tregs, with the level of PMN-MDCs in this subpopulation approaching that of healthy controls. PMN-MDSCs and Tregs jointly play a critical role in maintaining an immune-suppressive state suitable for B-ALL tumor progression. Thereby, they could be independent predictors of B-ALL progress, and finely targeting both PMN-MDSCs and Tregs may be a promising approach for the treatment of B-ALL.


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