One case of acute megakaryoblastic leukemia （AMKL） with trisomy 21,trisomy 14 and unmutated GATA1 gene in a phenotypically normal girl was reported.The patient experienced transient myelodysplasia before the onset o...One case of acute megakaryoblastic leukemia （AMKL） with trisomy 21,trisomy 14 and unmutated GATA1 gene in a phenotypically normal girl was reported.The patient experienced transient myelodysplasia before the onset of AMKL.The bone marrow blasts manifested typical morphology of megakaryoblast both by the May-Giemsa staining and under the electronic microscopy.Leukemic cells were positive for CD13,CD33,CD117,CD56,CD38,CD41 and CD61 in flow cytometry analysis.Cytogenetic study showed karyotype of 48,XX,＋14,＋21 in 40% metaphases.Known mutations of GATA1 gene in Down syndrome or acquired trisomy 21 were not detected in this case.展开更多
EAF1 and EAF2,the eleven-nineteen lysine-rich leukemia(ELL)-associated factors which can assemble to the super elongation complex(AFF1/4,AF9/ENL,ELL,and P-TEFb),are reported to participate in RNA polymeraseⅡto active...EAF1 and EAF2,the eleven-nineteen lysine-rich leukemia(ELL)-associated factors which can assemble to the super elongation complex(AFF1/4,AF9/ENL,ELL,and P-TEFb),are reported to participate in RNA polymeraseⅡto actively regulate a variety of biological processes,including leukemia and embryogenesis,but whether and how EAF1/2 function in hematopoietic system related hypoxia tolerance during embryogenesis remains unclear.Here,we unveiled that deletion of EAF1/2(eaf1^(-/-)and eaf2^(-/-))caused reduction in hypoxia tolerance in zebrafish,leading to reduced erythropoiesis during hematopoietic processes.Meanwhile,eaf1^(-/-)and eaf2^(-/-)mutants showed significant reduc-tion in the expression of key transcriptional regulators scl,lmo2,and gata1a in erythropoiesis at both 24 h post fertilization(hpf)and 72 hpf,with gata1a downregulated while scl and lmo2 upregulated at 14 hpf.Mechanistically,eaf1^(-/-)and eaf2^(-/-)mutants exhibited significant changes in the expression of epigenetic modified histones,with a significant increase in the binding enrichment of modified histone H3K27me3 in gata1a promoter rather than scl and lmo2 promoters.Additionally,eaf1^(-/-)and eaf2^(-/-)mutants exhibited a dynamic expression of canonical WNT/β-catenin signaling during erythropoiesis,with significant reduction in p-β-Catenin level and in the binding enrichment of both scl and lmo2 promoters with the WNT transcriptional factor TCF4 at 24 hpf.These findings demonstrate an important role of Eaf1/2 in erythropoiesis in zebrafish and may have shed some light on regeneration medicine for anemia and related diseases and on molecular basis for fish economic or productive traits,such as growth,disease resistance,hypoxia tolerance,and so on.展开更多
文摘One case of acute megakaryoblastic leukemia （AMKL） with trisomy 21,trisomy 14 and unmutated GATA1 gene in a phenotypically normal girl was reported.The patient experienced transient myelodysplasia before the onset of AMKL.The bone marrow blasts manifested typical morphology of megakaryoblast both by the May-Giemsa staining and under the electronic microscopy.Leukemic cells were positive for CD13,CD33,CD117,CD56,CD38,CD41 and CD61 in flow cytometry analysis.Cytogenetic study showed karyotype of 48,XX,＋14,＋21 in 40% metaphases.Known mutations of GATA1 gene in Down syndrome or acquired trisomy 21 were not detected in this case.
基金supported by the Nation Natural Science Foundation of China(Program No.32070807)by the National Key R&D Program of China(2018YFD0900101)by the project 2020SKLBC-KF06 of State Key Laboratory of Biocontrol.
文摘EAF1 and EAF2,the eleven-nineteen lysine-rich leukemia(ELL)-associated factors which can assemble to the super elongation complex(AFF1/4,AF9/ENL,ELL,and P-TEFb),are reported to participate in RNA polymeraseⅡto actively regulate a variety of biological processes,including leukemia and embryogenesis,but whether and how EAF1/2 function in hematopoietic system related hypoxia tolerance during embryogenesis remains unclear.Here,we unveiled that deletion of EAF1/2(eaf1^(-/-)and eaf2^(-/-))caused reduction in hypoxia tolerance in zebrafish,leading to reduced erythropoiesis during hematopoietic processes.Meanwhile,eaf1^(-/-)and eaf2^(-/-)mutants showed significant reduc-tion in the expression of key transcriptional regulators scl,lmo2,and gata1a in erythropoiesis at both 24 h post fertilization(hpf)and 72 hpf,with gata1a downregulated while scl and lmo2 upregulated at 14 hpf.Mechanistically,eaf1^(-/-)and eaf2^(-/-)mutants exhibited significant changes in the expression of epigenetic modified histones,with a significant increase in the binding enrichment of modified histone H3K27me3 in gata1a promoter rather than scl and lmo2 promoters.Additionally,eaf1^(-/-)and eaf2^(-/-)mutants exhibited a dynamic expression of canonical WNT/β-catenin signaling during erythropoiesis,with significant reduction in p-β-Catenin level and in the binding enrichment of both scl and lmo2 promoters with the WNT transcriptional factor TCF4 at 24 hpf.These findings demonstrate an important role of Eaf1/2 in erythropoiesis in zebrafish and may have shed some light on regeneration medicine for anemia and related diseases and on molecular basis for fish economic or productive traits,such as growth,disease resistance,hypoxia tolerance,and so on.
