Molecular mechanism to cause high incidence of cancer in Bloom syndrcme

布卢姆综合征致癌高发的分子机制

• 批准号: 13214007
• 负责人: ENOMOTO Takemi
• 金额: $ 37.12万
• 依托单位: Tohoku Universty
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research on Priority Areas
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13214007/
• 关键词: Bloom syndrome; BLM; Sgs1; sister chromatid exchange; Top3; chromosome abberation; homologous recombination; cartinogenesis; SUMO化; Sgsl; DNAトポイソメラーゼIII; Top3α; Xrcc3; SCE; ヘリカーゼ; 癌; ゲノム; 酵母Sgs1; BASC; ATM; MRE11

Bloom's syndrome is autosomal disorder characterized by predisposition to wide variety of cancers. In this study, I intended to clarify the function of the Bloom syndrome gene product (BLM) at the molecular level, using budding yeasts that have a BLM homologue, SGS1 as well as higher eukaryotic cells. Genetical analyses using yeasts indicated that Sgs1 functions to suppress homologous recombination under normal condition. However, Sgs1 was required to induce homologous recombination when cells were injured with DNA damaging agents. It has been revealed that the interaction of Sgs1 with DNA topoisomerase III (Top3) is essential for Sgs1 to fulfill its function and that Sgs1 functions in the Rad52 recombination pathway involving Rad51 but not Mre11.To elucidate the function of Top3 and functional relationship between BLM and Top3 in higher eukaryotic cells, we constructed cells with various genetic backgrounds whose Top3a expression is controllable. Depletion of Top3a from the cells caused accumulation of cells in G2 phase, enlargement of nuclei, chromosome gaps and breaks that occurred at the same position of sister chromatids, and inhibition of transition from metaphase to anaphase and that these events were suppressed by disruption of BLM gene, indicating a functional interaction between BLM and Top3a. Based on the results obtained in this study, we reached the conclusion that Top3a and BLM are implicated in the decatenation of DNA in newly synthesized sister chromatids. In addition, it has been indicated that BLM and Top3a function cooperatively to suppress the formation of sister chromatid exchange. Finally, epistatic analyses using various gene knockout cells, suggested that BLM functions in the recombination pathway involving XRCC3 under damage induced condition.

Bloom综合征是常染色体疾病，其特征是多种癌症。在这项研究中，我打算使用具有BLM同源物，SGS1以及更高的真核细胞的发芽酵母在分子水平上在分子水平上阐明Bloom综合征基因产物（BLM）的功能。使用酵母菌进行的基因分析表明，SGS1在正常情况下抑制同源重组的功能。但是，当细胞受到DNA损伤剂受伤时，需要SGS1诱导同源重组。已经揭示了SGS1与DNA拓扑异构酶III（TOP3）的相互作用对于SGS1实现其功能至关重要，并且SGS1在RAD52重组途径中的功能涉及RAD51，但不是MRE11。和TOP3在较高的真核细胞中，我们构建了具有各种遗传背景的细胞，其TOP3A表达是可控的。 TOP3A从细胞中耗尽引起G2期的细胞积累，核的扩大，染色体间隙和发生在姐妹染色质相同位置的断裂，以及抑制从中期到过后生的过渡，这些事件被BLM BLM抑制基因，表明BLM和TOP3A之间存在功能相互作用。根据这项研究中获得的结果，我们得出的结论是，TOP3A和BLM与新合成的姐妹染色单体中DNA的衰减有关。此外，已经表明BLM和TOP3A合作抑制姐妹染色单体交换的形成。最后，使用各种基因基因敲除细胞的上皮分析表明，BLM在损害诱导条件下涉及XRCC3的重组途径中的功能。

项目成果

Nao Odagiri: "Budding yeast mms4 is epistatic with rad52 and its function can be replaced by a bacterial Holliday junction resolvase"DNA repair. 2. 347-358 (2003)

Nao Odagiri：“芽殖酵母 mms4 与 rad52 上位，其功能可以被细菌霍利迪连接体解析酶取代”DNA 修复。

MC6 is required for MMS-induced interchromosomal and sister chromatid recombinations in Saccharomyces cerevisiae

MC6 是 MMS 诱导的酿酒酵母染色体间和姐妹染色单体重组所必需的

• 发表时间: 2004
• 期刊: DNA Repair 3
• 作者: Seiki Hirano;Ayako Ui;Seiki Hirano;Ayako Ui;Changwok Lee;Fumitoshi Onoda;Wensheng Wang;Changwok Lee;Fumitoshi Onoda
• 通讯作者: Fumitoshi Onoda

SMC6 is required for MMS-induced interchromosomal and sister chromatid recombinations in Saccharomyces cerevisiae.

• DOI: 10.1016/j.dnarep.2003.12.007
• 发表时间: 2004-04
• 期刊: DNA repair
• 影响因子: 3.8
• 作者: F. Onoda;M. Takeda;M. Seki;D. Maeda;J. Tajima;A. Ui;H. Yagi;T. Enomoto

Saccharomyces cerevisiae WHIP/MGS1 gene interacts genetically with DNA replication genes.

酿酒酵母 WHIP/MGS1 基因与 DNA 复制基因存在遗传相互作用。

• 发表时间: 2002
• 期刊: Mol.Genet.Genomics 268
• 作者: Seiki Hirano;Ayako Ui;Seiki Hirano;Ayako Ui;Changwok Lee;Fumitoshi Onoda;Wensheng Wang;Changwok Lee;Fumitoshi Onoda;Wensheng Wang;Daisuke Maeda;Wensheng Wang;Wensheng Wang;Dana Branzei;Dana Branzei;Dana Branzei;Dana Branzei
• 通讯作者: Dana Branzei

Takayuki Kobayashi: "Focus-formation of replication protein A, activation of checkpoint system and DNA repair synthesis induced by DNA double-strand breaks in Xenopus egg extract"J.Cell Science. 115. 3159-3169 (2002)

Takayuki Kobayashi：“非洲爪蟾卵提取物中 DNA 双链断裂诱导的复制蛋白 A 的焦点形成、检查点系统的激活和 DNA 修复合成”J.Cell Science。