Roles of BRCA1 in sporadic breast cancer

BRCA1 在散发性乳腺癌中的作用

• 批准号: 16591279
• 负责人: FUKUDA Mamoru
• 金额: $ 2.11万
• 依托单位: St.Marianna University School of Medicine
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16591279/
• 关键词: BRCA1; BARD1; familial breast cancer; ubiquitin ligase; RPB8; SPIN; Cyclin E; Nucleophosmin; RINGフィンガー

The breast and tumor suppressor BRCA1 is a hub protein that integrates multiple cellular pathways, and its functional failure is implicated in the carcinogenesis of sporadic breast cancer. I have investigated the possible importance of factors act in the BRCA1 ubiquitin ligase cascade as biological indicators for sporadic breast cancer. I focused in BRCA1 inhibition by CDK2-Cyclin E in 2004. CDK2-Cyclin E destabilized BRCA1 at protein level in vivo and dramatically inhibited BRCA1's ubiquitin ligase activity. Therefore I analyzed expression pattern of BRCA1 and Cyclin E in primary breast cancer tissues by immunohistochemistry. The BRCA1 expression was reversely correlated with Cyclin E. In 2005 I mainly investigated RPB8, a subunit of RNA polymerases, and spindle-associated protein SPIN, that I have identified as substrates of BRCA1 by proteomics screens. RPB8 was ubiquitinated by BRCA1-BARD1 in vivo and in vitro, and the ubiquitination was abolished by substitution of five Lys residues of RPB8 with Arg. HeLa cell line stably expressing this ubiquitin resistant mutant of RPB8 exhibited hypersensitivity to DNA damage, the phenotype known in cells with BRCA1 deficiency. Interestingly two of the five Lys residues were substituted in human as single nucleotide polymorphisms (SNPs), that could be implicated in breast cancer susceptibility or sensitivity to anti-cancer reagents such as anthracyclin. A part of the results has been submitted for publication. I also found that endogenous or overexpressed SPIN interacted with BRCA1, and BRCA1-BARD1 dependent polyubiquitination of SPIN in vivo. I established antibodies to RPB8 and SPIN and tested its availability for immunohistochemistry. However, we have not determined appropriate condition to detect the proteins in breast cancer specimens yet.

乳腺癌和肿瘤抑制因子BRCA 1是一种整合多种细胞通路的枢纽蛋白，其功能失效与散发性乳腺癌的发生有关。我已经研究了BRCA 1泛素连接酶级联反应中的因子作为散发性乳腺癌生物学指标的可能重要性。2004年，我专注于CDK 2-Cyclin E对BRCA 1的抑制。CDK 2-Cyclin E在体内蛋白水平上使BRCA 1不稳定，并显著抑制BRCA 1的泛素连接酶活性。因此，我用免疫组化方法分析BRCA 1和Cyclin E在原发性乳腺癌组织中的表达模式。BRCA 1表达与Cyclin E呈显著正相关。在2005年，我主要研究了RPB 8，RNA聚合酶的亚基，和纺锤体相关蛋白SPIN，我已经通过蛋白质组学筛选确定为BRCA 1的底物。BRCA 1-BARD 1在体内和体外均能泛素化RPB 8，并通过将RPB 8的5个赖氨酸残基替换为精氨酸（Arg）来消除RPB 8的泛素化。稳定表达RPB 8的这种泛素抗性突变体的HeLa细胞系表现出对DNA损伤的超敏反应，这是BRCA 1缺陷细胞中已知的表型。有趣的是，5个Lys残基中的2个在人类中被取代为单核苷酸多态性（SNP），这可能与乳腺癌易感性或对抗癌试剂如蒽环类药物的敏感性有关。部分结果已提交出版。我还发现，内源性或过表达的SPIN与BRCA 1相互作用，以及体内SPIN的BRCA 1-BARD 1依赖性多泛素化。我建立了RPB 8和SPIN的抗体，并测试了其免疫组织化学的可用性。然而，我们还没有确定合适的条件来检测乳腺癌标本中的蛋白质。

项目成果

BRCA1ユビキチンリガーゼと乳癌

BRCA1 泛素连接酶与乳腺癌

• 发表时间: 2004
• 期刊: 医学のあゆみ 211(1)
• 作者: Matsushita N;Kitao H;Ishiai M;Nagashima N;Hirano S;Okawa K;Ohta T;Yu DS;McHugh PJ;Hickson ID;Venkitaraman AR;Kurumizaka H;Takata M.;Matsushita N;Makiko Tsuzuki;Jian Hu;Ko Sato;太田智彦;太田智彦
• 通讯作者: 太田智彦

Breast tumor suppressor BRCA1

乳腺肿瘤抑制因子 BRCA1

• 发表时间: 2004
• 期刊: New Horizon Med. (Japanese) 36(4)
• 作者: Ohta T;Hayami R;Wu W;Fukuda M.
• 通讯作者: Fukuda M.

Down-regulation of BRCA1-BARD1 ubiquitin ligase by CDK2.

CDK2 下调 BRCA1-BARD1 泛素连接酶。

• 发表时间: 2005
• 期刊: Cancer Res. 65
• 作者: Hayami R;Sato K;Wu W;Nishikawa T;Hiroi J;Ohtani-Kaneko R;Fukuda M;Ohta T.
• 通讯作者: Ohta T.

Nucleophosmin/B23 is a candidate substrate for the BRCA1-BARD1 ubiquitin ligase

• DOI: 10.1074/jbc.c400169200
• 发表时间: 2004-07-23
• 期刊: JOURNAL OF BIOLOGICAL CHEMISTRY
• 影响因子: 4.8
• 作者: Sato, K;Hayami, R;Ohta, T
• 通讯作者: Ohta, T

A truncated splice bariant of human BARD1 that lacks the RING finger and ankyrin repeat.

人类 BARD1 的截短剪接体，缺少环指和锚蛋白重复序列​​。

• 发表时间: 2005
• 期刊: Cancer Lett. in press
• 作者: Nishida_M;Nagao T;Kurose H.(15);Bravou V. et al.;Xouri G. et al.;Sugimoto N. et al.;Nishitani H. et al.;西谷 秀男;Sei-ichi Tanuma;Sei-ichi Tanuma;Sei-ichi Tanuma;Sei-ichi Tanuma;Sei-ichi Tanuma;田沼 靖一;Sei-ichi Tanuma;Sei-ichi Tanuma;Sei-ichi Tanuma;Sei-ichi Tanuma;Sei-ichi Tanuma;Atsushi Yamauchi;Vinciane Regnier;Yoshikazu Mikami;深川竜郎;深川竜郎;Matsushita N;Makiko Tsuzuki
• 通讯作者: Makiko Tsuzuki