B-cell acute lymphoblastic leukemia(B-ALL)is a malignant tumor originating from B-lineage lymphoid precursor cells.The incidence of B-ALL is about 80%in childhood acute leukemia and 20%in adults.In recent years,with s...B-cell acute lymphoblastic leukemia(B-ALL)is a malignant tumor originating from B-lineage lymphoid precursor cells.The incidence of B-ALL is about 80%in childhood acute leukemia and 20%in adults.In recent years,with standardized treatment guided by risk stratification,the long-term disease-free survival rate of children is about 80%,while that of adults is less than 40%.However,the specific pathogenesis of the newly identified B-ALL and the targeted therapy strategies have not been vigorously investigated.In this review,we highlight the recent breakthroughs in mechanistic studies and novel therapeutic options in DUX4-and MEF2D-subtype B-ALLs.展开更多
Background:Abnormal alternative splicing is frequently associated with carcinogenesis.In B-cell acute lymphoblastic leukemia(B-ALL),double homeobox 4 fused with immunoglobulin heavy chain(DUX4/IGH)can lead to the aber...Background:Abnormal alternative splicing is frequently associated with carcinogenesis.In B-cell acute lymphoblastic leukemia(B-ALL),double homeobox 4 fused with immunoglobulin heavy chain(DUX4/IGH)can lead to the aberrant production of E-26 transformation-specific family related gene abnormal transcript(ERGalt)and other splicing variants.However,the molecular mechanism underpinning this process remains elusive.Here,we aimed to know how DUX4/IGH triggers abnormal splicing in leukemia.Methods:The differential intron retention analysis was conducted to identify novel DUX4/IGH-driven splicing in B-ALL patients.X-ray crystallography,small angle X-ray scattering(SAXS),and analytical ultracentrifugation were used to investigate how DUX4/IGH recognize double DUX4 responsive element(DRE)-DRE sites.The ERGalt biogenesis and B-cell differentiation assays were performed to characterize the DUX4/IGH crosslinking activity.To check whether recombination-activating gene 1/2(RAG1/2)was required for DUX4/IGH-driven splicing,the proximity ligation assay,co-immunoprecipitation,mammalian two hybrid characterizations,in vitro RAG1/2 cleavage,and shRNA knock-down assays were performed.Results:We reported previously unrecognized intron retention events in Ctype lectin domain family 12,member A abnormal transcript(CLEC12Aalt)and chromosome 6 open reading frame 89 abnormal transcript(C6orf89alt),where also harbored repetitive DRE-DRE sites.Supportively,X-ray crystallography and SAXS characterization revealed that DUX4 homeobox domain(HD)1-HD2 might dimerize into a dumbbell-shape trans configuration to crosslink two adjacent DRE sites.Impaired DUX4/IGH-mediated crosslinking abolishes ERGalt,CLEC12Aalt,and C6orf89alt biogenesis,resulting in marked alleviation of its inhibitory effect on B-cell differentiation.Furthermore,we also observed a rare RAG1/2-mediated recombination signal sequence-like DNA edition in DUX4/IGH target genes.Supportively,shRNA knock-down of RAG1/2 in leukemic Reh cells consistently impaired the biogenesis of ERGalt,CLEC12Aalt,and C6orf89alt.Conclusions:All these results suggest that DUX4/IGH-driven DNA crosslinking is required for RAG1/2 recruitment onto the double tandem DRE-DRE sites,catalyzing V(D)J-like recombination and oncogenic splicing in acute lymphoblastic leukemia.展开更多
基金This work was supported by research grants 81970132,81770142,81800144,and 31800642 from National Natural Science Foundation of Chinaa research grant 20JC1410600 from Shanghai Science and Technology Committee+1 种基金Shanghai Guangci Translational Medical Research Development Foundationa research grant 20152504 from“Shanghai Municipal Education Commission-Gaofeng Clinical Medicine Grant Support”,“The Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institute of Higher Learning”,Samuel Waxman Cancer Research Foundation。
文摘B-cell acute lymphoblastic leukemia(B-ALL)is a malignant tumor originating from B-lineage lymphoid precursor cells.The incidence of B-ALL is about 80%in childhood acute leukemia and 20%in adults.In recent years,with standardized treatment guided by risk stratification,the long-term disease-free survival rate of children is about 80%,while that of adults is less than 40%.However,the specific pathogenesis of the newly identified B-ALL and the targeted therapy strategies have not been vigorously investigated.In this review,we highlight the recent breakthroughs in mechanistic studies and novel therapeutic options in DUX4-and MEF2D-subtype B-ALLs.
基金National Natural Science Foundation of China,Grant/Award Numbers:81970132,81770142,81800144,31800642Shanghai Science and Technology Committee,Grant/Award Number:20JC1410600+3 种基金Shanghai Guangci Translational Medical Research Development FoundationShanghai Municipal Education Commission-Gaofeng Clinical Medicine Grant Support,Grant/Award Number:20152504The Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institute of Higher LearningSamuel Waxman Cancer Research Foundation。
文摘Background:Abnormal alternative splicing is frequently associated with carcinogenesis.In B-cell acute lymphoblastic leukemia(B-ALL),double homeobox 4 fused with immunoglobulin heavy chain(DUX4/IGH)can lead to the aberrant production of E-26 transformation-specific family related gene abnormal transcript(ERGalt)and other splicing variants.However,the molecular mechanism underpinning this process remains elusive.Here,we aimed to know how DUX4/IGH triggers abnormal splicing in leukemia.Methods:The differential intron retention analysis was conducted to identify novel DUX4/IGH-driven splicing in B-ALL patients.X-ray crystallography,small angle X-ray scattering(SAXS),and analytical ultracentrifugation were used to investigate how DUX4/IGH recognize double DUX4 responsive element(DRE)-DRE sites.The ERGalt biogenesis and B-cell differentiation assays were performed to characterize the DUX4/IGH crosslinking activity.To check whether recombination-activating gene 1/2(RAG1/2)was required for DUX4/IGH-driven splicing,the proximity ligation assay,co-immunoprecipitation,mammalian two hybrid characterizations,in vitro RAG1/2 cleavage,and shRNA knock-down assays were performed.Results:We reported previously unrecognized intron retention events in Ctype lectin domain family 12,member A abnormal transcript(CLEC12Aalt)and chromosome 6 open reading frame 89 abnormal transcript(C6orf89alt),where also harbored repetitive DRE-DRE sites.Supportively,X-ray crystallography and SAXS characterization revealed that DUX4 homeobox domain(HD)1-HD2 might dimerize into a dumbbell-shape trans configuration to crosslink two adjacent DRE sites.Impaired DUX4/IGH-mediated crosslinking abolishes ERGalt,CLEC12Aalt,and C6orf89alt biogenesis,resulting in marked alleviation of its inhibitory effect on B-cell differentiation.Furthermore,we also observed a rare RAG1/2-mediated recombination signal sequence-like DNA edition in DUX4/IGH target genes.Supportively,shRNA knock-down of RAG1/2 in leukemic Reh cells consistently impaired the biogenesis of ERGalt,CLEC12Aalt,and C6orf89alt.Conclusions:All these results suggest that DUX4/IGH-driven DNA crosslinking is required for RAG1/2 recruitment onto the double tandem DRE-DRE sites,catalyzing V(D)J-like recombination and oncogenic splicing in acute lymphoblastic leukemia.
