Research Project 3: Role of the NF-kB/Rel in Mammary Carcinogenesis

乳腺癌的发病率在过去的50年里有所上升，现在它是第二大原因， 美国女性的死亡为了找到发病率增加的原因，遗传， 正在研究环境和饮食因素。二聚体转录因子的NF-κ B家族， 控制肿瘤转化、细胞增殖和存活的关键基因，由五个成员组成： 3个具有反式激活结构域（c-Rel、RelA、RelB），2个不具有（p50和p52），其促进更强的 约束力在大多数细胞中，NF-κ B因子以无活性复合物的形式被隔离在细胞质中。协同 该项目成员的研究表明，c-Rel、RelA或 p50 NF-κ B亚基在约90%的原发性人乳腺癌中的表达，以及暴露于多环芳烃 碳氢化合物（PAHs），如7，12-二甲基苯并（a）蒽（DMBA）或苯并（a）芘，上调 乳腺癌中的NF-κ B。这使我们在最初的申请中提出了一个中心假设，即致癌物质可以 组成型激活NF-κ B，这将促进转化。与项目1和2合作，我们 最近的研究表明，由PAH暴露诱导的NF-κ B复合物在 通过上皮向间质转化（EMT）促进乳腺癌的侵袭性表型。(1)PAH 暴露于小鼠活化的多种NF-κ B复合物、IKKe/i激酶和乳腺癌侵袭性表型 （2）c-Rel驱动的乳腺癌细胞的PAH暴露进一步激活了NF-κ B，这是肿瘤生长所必需的。 （3）c-Rel亚基在乳腺肿瘤的发生中起着重要的作用，并与乳腺癌的发生、发展密切相关 与蛋白激酶CK 2一起诱导AhR和Slug（EMT的主要调节因子）;（4）一种新的从头RelB （5）RelB通过Bcl-2的诱导表达，促进EMT的发生; DMBA或c-Rel，并在人乳腺癌标本中表达。值得注意的是，绿色茶及其多酚 表没食子儿茶素-3没食子酸酯（EGCG）降低了DMBA诱导的乳腺肿瘤的侵袭性表型， 乳腺癌细胞表没食子儿茶素没食子酸酯对Her-2/neu乳腺癌耐药细胞系增殖的抑制作用 曲妥珠单抗，提示绿色茶多酚的转化应用。因此，环境 已知致癌物在乳腺组织中诱导遗传和表观遗传事件。本修订 更新的应用，我们建议测试的假设，这些扰动诱导或增强 多个NF-κ B复合物的活性，从而促进乳腺癌更具侵袭性的表型：因此 这些途径的抑制将逆转EMT的过程。提出了三个目标：（1）阐明角色 c-Rel和RelB NF-κ B在促癌中的作用;（2）确定IKKe/i在癌发生中的作用， 以及IKKs/i启动子激活的机制;（3）进行临床前体内绿色的能力测试 茶多酚降低Her-2/neu介导的转化。这些研究将提供重要的 关于环境因素激活NF-κ B因子异常表达的机制的信息 致癌物，并表征其在促进浸润性乳腺癌中的作用。绿色茶多酚是 潜在的乳腺癌抑制剂，可以很容易地转化为临床组合疗法。

The incidence of breast cancer has risen over the past 50 years, and it is now the second leading cause of death among American women. In an attempt to find the reasons for this increase in incidence, genetic, environmental and dietary factors are being studied. The NF-KB family of dimeric transcription factors, which controls genes critical for neoplastic transformation, cell proliferation and survival, consists of five members: 3 with transactivation domains (c-Rel, RelA, RelB), and 2 without (p50 and p52), which promote stronger binding. NF-KB factors are sequestered in the cytoplasm in inactive complexes in most cells. Collaborative studies by members of the Program Project demonstrated constitutive aberrant activation of c-Rel, RelA or p50 NF-KB subunits in -90% of primary human breast cancers, and that exposure to polycyclic aromatic hydrocarbons (PAHs), such as 7,12-dimethylbenz(a)anthracene (DMBA) or benzo(a)pyrene, up-regulated NF-KB in breast cancer. This led us to the central hypothesis in the original application that carcinogens can constitutively activate NF-KB, which will promote transformation. In collaboration with Projects 1 and 2, we have more recently shown that NF-KB complexes, which are induced by PAH exposure, play key roles in promoting an invasive phenotype of breast cancer via epithelial to mesenchymal transition (EMT). (1) PAH exposure of mice activated multiple NF-KB complexes, the IKKe/i kinase and an invasive phenotype of mammary tumors; (2) PAH exposure of c-Rel-driven breast cancer cells further activated NF-KB, which was required for an invasive phenotype; (3) the c-Rel subunit can play a causal role in mammary tumorigenesis and cooperated with protein kinase CK2 to induce the AhR and Slug, a master regulator of EMT; (4) a novel de novo RelB synthesis pathway was identified, which promoted EMT via induction of Bcl-2; (5) RelB was induced by DMBA or c-Rel and expressed in human breast cancer specimens. Of note, green tea and its polyphenol epigallocatechin-3 gallate (EGCG) reduced invasive phenotype of DMBA-induced mammary tumors and breast cancer cells. EGCG slowed proliferation of Her-2/neu breast cancer cell lines resistant to trastuzumab, suggesting translational applications of green tea polyphenols. Thus, environmental carcinogens are known to induce genetic as well as epigenetic events in mammary tissue. In this revised renewal application, we propose to test the hypothesis that these perturbations induce or enhance the activity of multiple NF-KB complexes thereby promoting a more invasive phenotype of breast cancer: thus inhibition of these pathways will revert the process of EMT. Three aims are proposed: (1) elucidate the roles of c-Rel and RelB NF-KB in promoting carcinogenesis; (2) determine the function of IKKe/i in carcinogenesis, and the mechanism of IKKs/i promoter activation; (3) perform pre-clinical in vivo testing of the ability of green tea polyphenols to reduce Her-2/neu-mediated transformation. These studies will provide important information on the mechanisms of activation of aberrant expression of NF-KB factors by environmental carcinogens, and characterize their roles in promoting invasive breast cancer. Green tea polyphenols are potential inhibitors of breast cancer that can readily be translated to the clinic for combinatorial therapies.