Molecular analysis of leukemias with chromosomal translocation and its application for clinical Diagnosis

染色体易位白血病的分子分析及其在临床诊断中的应用

• 批准号: 05454328
• 负责人: HIRAI Hisamaru
• 金额: $ 4.1万
• 依托单位: University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05454328/
• 关键词: CML; blastic crisis; chromosomal translocation; AML1; EVI-1; chimeric protein; differentiation suppression; growth stimulation; Evi-1; 転座型白血病; t(3;21)転座; AML1; EVI-1キメラ遺伝子; 転写因子

The t (3 ; 21) (q26 ; q22) translocation, which is one of consistent chromosomal abnormalities found in blastic crisis of chronic myelocytic leukemia (CML) , is thought to play an important role in leukemic progression of CML to an acute blastic crisis phase. The AML1 gene, which is located at the translocation breakpoint of the t (8 ; 21) (q22 ; q22) translocation found in acute myelocytic leukemia, was also rearranged by the t (3 ; 21) (q26 ; q22) translocation. Screening of a cDNA library of the t (3 ; 21) -carrying leukemic cell line cells (SKH1) resulted in the isolation of AML1/EVI-1 chimeric cDNAs. SKH1 cells expressed the 180 Kd AML1-EVI-1 fusion protein containing an amino-terminal half of AML1 including a runt homology domain which is fused to the entire of zinc finger EVI-1 protein. These findings strongly suggest that the t (3 ; 21) translocation results in the formation of a new class of a chimeric transcription factor which could contribute to leukemic progression of CML … More through interference with cell growth and differentiation. Biochemical analyzes revealed that AML1/EVI-1 itself does not alter the transactivation level through PEBP2 sites but dominantly suppresses the transactivation by intact AML1, which is assumed to be a stimulator of myeloid cell differentiation. The DNA-binding competition is a putative mechanism of such dominant negative effects of AML1/EVI-1 because it binds to PEBP2 sites in the higher affinity than AML1. Furthermore, AML1/EVI-1 stimulated the c-fos promoter transactivation and raised the AP-1 activity. Experiments, using deletion mutants of AML1/EVI-1, showed that these two functions are mutually independent because the dominant negative effects upon intact AML1 and the stimulation of AP-1 activity are dependent on the runt domain and the zinc finger domain near the C-terminus, respectively. Furthermore we showed that AML1/EVI-1 blocks granulocytic differentiation, otherwise induced by G-CSF,of 32Dc13 myeloid cells. It was also suggested that both AML1-derived and EVI-1-derived portions of the fusion protein play crucial roles for such differentiation block. We conclude that the leukemic cell transformation in t (3 ; 21) leukemias is probably caused by those dual functions of AML1/EVI-1 chimeric protein. Less

t（3 ; 21）（q26 ; q22）易位是慢性粒细胞白血病（CML）急变期常见的染色体异常之一，被认为在CML向急性急变期的进展中起重要作用。AML 1基因位于急性髓细胞白血病中发现的t（8 ; 21）（q22 ; q22）易位的易位断裂点，也被t（3 ; 21）（q26 ; q22）易位重排。筛选携带t（3 ; 21）的白血病细胞系细胞（SKH 1）的cDNA文库导致分离AML 1/EVI-1嵌合cDNA。SKH 1细胞表达180 Kd的AML 1-EVI-1融合蛋白，其含有AML 1的氨基末端的一半，包括与整个锌指EVI-1蛋白融合的runt同源结构域。这些发现有力地表明t（3 ; 21）易位导致一类新的嵌合转录因子的形成，这可能有助于CML的白血病进展 ...更多信息 通过干扰细胞生长和分化。生化分析显示，AML 1/EVI-1本身不改变通过PEBP 2位点的反式激活水平，但主要抑制由完整的AML 1，这被认为是一个刺激剂的髓样细胞分化的反式激活。DNA结合竞争是AML 1/EVI-1的这种显性负效应的推定机制，因为它以比AML 1更高的亲和力结合PEBP 2位点。AML 1/EVI-1还能激活c-fos启动子的转录，提高AP-1的活性。使用AML 1/EVI-1缺失突变体的实验表明，这两种功能是相互独立的，因为对完整AML 1的显性负效应和AP-1活性的刺激分别依赖于C末端附近的runt结构域和锌指结构域。此外，我们发现，AML 1/EVI-1块粒细胞分化，否则诱导的G-CSF，32 Dc 13髓样细胞。还表明融合蛋白的AML 1衍生部分和EVI-1衍生部分在这种分化阻断中起关键作用。结论：t（3 ; 21）白血病的白血病细胞转化可能是由AML 1/EVI-1嵌合蛋白的双重功能引起的。少

项目成果

Mitani K: "Generation of the AML1/Evi-1 fusion gene in the t(3:21)(q26;q22)causes blastic crisis in chronic myelocytic leukemia." EMBO J.13. 504-510 (1994)

Mitani K：“t(3:21)(q26;q22) 中 AML1/Evi-1 融合基因的产生会导致慢性粒细胞白血病的急变期。”

Harada H,Kondo T,Ogawa S,Tamura T,Kitagawa M,Tanaka N,Lamphier MS,Hirai H.: "Taniguchi T.Accelerated exon skipping of IRF-1 mRNA in human myelodysplasia/leukemia ; A possible mechanism of tumor suppressor inactivation." Oncogene. 9. 3313-3320 (1994)

原田 H、近藤 T、小川 S、田村 T、北川 M、田中 N、兰菲尔 MS、平井 H.：“Taniguchi T.人类骨髓增生异常/白血病中 IRF-1 mRNA 的加速外显子跳跃；肿瘤抑制因子失活的可能机制

Ogawa S: "Homozygous loss of the cyclin-dependent kinase 4-inhibitor(p16)gene in human leukemias." Blood. 84. 2431-2435 (1994)

Okawa S：“人类白血病中细胞周期蛋白依赖性激酶 4 抑制剂 (p16) 基因的纯合性缺失。”

Tanaka T,Nishida J,Mitani K,Yazaki Y,Hirai H.: "Evi-1 raises AP-1 activity and stimulates c-fos promoter transactivation with dependence on the second zinc finger domain." J.Biol.Chem.269. 24020-24026 (1994)

Tanaka T、Nishida J、Mitani K、Yazaki Y、Hirai H.：“Evi-1 提高 AP-1 活性并刺激 c-fos 启动子反式激活，依赖于第二个锌指结构域。”

Tanaka T: "Evi-1 raoses AP-1 activity and stimulates c-fos promoter transactivation with dependence on the second zinc finger domain." J.Biol.Chem. 269. 24020-24026 (1994)

Tanaka T：“Evi-1 提高 AP-1 活性并刺激 c-fos 启动子反式激活，依赖于第二个锌指结构域。”