Molecular diagnosis and theray of infantile acute leukemia carrying 11q23 translocations

11q23易位婴儿急性白血病的分子诊断与治疗

• 批准号: 09670859
• 负责人: AKAO Yukihiro
• 金额: $ 2.24万
• 依托单位: Institute of Applied Biochemistry
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09670859/
• 关键词: Leukemia; imfantile leukemia; chromosome translocation; 11q23; MLLgene; antisense DNA; t(11;19) translocation; PCR; 染色体11番q23; アンチセンスオリゴヌクレオチド; アポトーシス; ヒ素; キメラ蛋白

Chromosome band 11q23 is a common breakpoint of chromosome translocations in a variety of leukemias and lymphomas such as infantile leukemias and secondary leukemias associated with epipodophyllotoxin treatment. Generally, the leukemias carrying 1lq23 translocations have poor prognosis. Two groups cloned MLL which is involved in t(4 ; 11)(q21 ; q23) and t(11 ; 19)(q23 ; pl3). We also cloned the breakpoint of t(11 ; 19)(q23 ; pl3) translocations observed in KOCL33 and KOCL44 cell lines originated from infantile acute leukemias and found that the MLL-LTG19/ENL is formed by the t(11 ; 19) translocation. Further, it was found that MLL is involved in t(11 ; 17) and t(11 ; 22) translocations, and came to the conclusion that MLL is responsible for the major 11q23 translocations. A sequencing study demonstrated that MLL is related to the Drosophila trithorax gene encoding a protein containing two DNA-binding motifs as a transcriptional factor. The molecular mechanism of the leukemogenesis in 1lq23 translocations involving MLL is explained by the fact that the chimeric proteins from MLL-partner genes are produced in a nonregulated manner, resulting in the dysfunction of MLL protein, which could be the cause of leukemogenesis.To clarify the role of MLL-LTG19 protein in leukemogenesis, we synthesized the antisense oligodeoxyribonucleotide (ODN) against the fused region of MLL-LTG19 chimeric transcript and treated KOCL33 cells having t(11 ; 19) with the antisense ODN. The antisense ODN inhibited cell growth and induced apoptosis in KOCL33 cells, but not in Daudi cells, which have no t(11 ; 19). The levels of MLL-LTG19 mRNA and MLL-LTG19 protein in KOCL33 cells treated with antisense ODN were shown to decrease with time by RT-PCR and Western blot analysis. These results suggest that the MLL-LTG19 fusion protein contributes to cell proliferation and malignant transformation in infantile acute leukemia cells having t(11 ; 19).

染色体带 11q23 是多种白血病和淋巴瘤（例如与表鬼臼毒素治疗相关的婴儿白血病和继发性白血病）中染色体易位的常见断点。一般来说，携带1lq23易位的白血病预后较差。两组克隆了涉及t(4；11)(q21；q23)和t(11；19)(q23；pl3)的MLL。我们还克隆了在源自婴儿急性白血病的 KOCL33 和 KOCL44 细胞系中观察到的 t(11 ; 19)(q23 ; pl3) 易位断点，并发现 MLL-LTG19/ENL 是由 t(11 ; 19) 易位形成的。此外，发现MLL参与t(11；17)和t(11；22)易位，并得出MLL负责主要11q23易位的结论。测序研究表明，MLL 与果蝇 trithorax 基因相关，该基因编码含有两个 DNA 结合基序作为转录因子的蛋白质。涉及MLL的1lq23易位导致白血病发生的分子机制是这样的：MLL伴侣基因的嵌合蛋白以不受调控的方式产生，导致MLL蛋白功能障碍，这可能是白血病发生的原因。为了阐明MLL-LTG19蛋白在白血病发生中的作用，我们合成了反义蛋白MLL-LTG19。 针对MLL-LTG19嵌合转录物的融合区域的寡脱氧核糖核苷酸(ODN)并用反义ODN处理具有t(11；19)的KOCL33细胞。反义ODN在KOCL33细胞中抑制细胞生长并诱导细胞凋亡，但在没有t(11；19)的Daudi细胞中则不然。 RT-PCR和Western blot分析显示，用反义ODN处理的KOCL33细胞中MLL-LTG19 mRNA和MLL-LTG19蛋白的水平随着时间的推移而降低。这些结果表明MLL-LTG19融合蛋白有助于具有t(11；19)的婴儿急性白血病细胞的细胞增殖和恶性转化。

项目成果

Akao Y., Mizoguchi H., Ohishi H., Ohishi N., Yagi K.: "Antisense oligodeoxyribonucleotide against the MLL-LTG19 chimeric transcript inhibits cell growth and intuces apoptosis in cells of an infanitile leukemia cell line carrying the t(11;19) translocation

Akao Y.、Mizoguchi H.、Ohishi H.、Ohishi N.、Yagi K.：“针对 MLL-LTG19 嵌合转录物的反义寡脱氧核糖核苷酸可抑制携带 t(11; 的婴儿白血病细胞系的细胞生长并诱导细胞凋亡)

Akao Y., Mizoguchi H., Ohishi H., Ohishi N., Yagi K.: "Arsenic induces apoptosis in B-cell leukemic cell lines in vitro: activation of caspases and down-regulation of Bcl-2 protein"Britishi Journal of Haematology. 102. 1055-1060 (1998)

Akao Y.、Mizoguchi H.、Ohishi H.、Ohishi N.、Yagi K.：“砷在体外诱导 B 细胞白血病细胞系凋亡：激活半胱天冬酶并下调 Bcl-2 蛋白”《英国杂志》

Akao Y., Mizoguchi H., Ohishi N., Yagi K.: "Antisense oligodeoxyribonucleotide against the MILL-LTG19 chimeric transcript inhibits cell grownth and induces apoptosis in cells of an infantile leukemia cell line carrying the t(11 ; 19) translocation"Cancer

Akao Y.、Mizoguchi H.、Ohishi N.、Yagi K.：“针对 MILL-LTG19 嵌合转录物的反义寡脱氧核糖核苷酸可抑制携带 t(11 ; 19) 易位的婴儿白血病细胞系的细胞生长并诱导细胞凋亡”

Akao Y., Mizoguchi H., Ohishi N., Yagi K.: "Arsenic induces apoptosis in B-cell leukemic cell lines in vitro : activation of caspases and down-regulation of Bcl-2 protein"British Journal of Haematology. 102. 1055-1060 (1998)

Akao Y.、Mizoguchi H.、Ohishi N.、Yagi K.：“砷在体外诱导 B 细胞白血病细胞系凋亡：激活半胱天冬酶并下调 Bcl-2 蛋白”《英国血液学杂志》。

AKao Y., Mizoguchi H., Ohishi N., Yagi K.: "Arsenic induces apoptosis in B-cell leukemic cell lines in vitro: activation of caspases and down-regulation of Bcl-2 protein" British Journal of Haematology. 102. 1055-1060 (1998)

AKao Y.、Mizoguchi H.、Ohishi N.、Yagi K.：“砷在体外诱导 B 细胞白血病细胞系凋亡：激活半胱天冬酶并下调 Bcl-2 蛋白”《英国血液学杂志》。