Role of Eya3 in regulating the immune microenvironment to promote breast tumor progression

Eya3在调节免疫微环境促进乳腺肿瘤进展中的作用

• 批准号: 10218071
• 负责人: Heide L. Ford
• 金额: $ 62.06万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10218071
• 关键词: Adaptive Immune System; Angiogenesis Inhibition; Antineoplastic Agents; Binding; Biochemical; C-terminal; CD8-Positive T-Lymphocytes; Catalytic Domain; Cell Survival; Cell physiology; Cells; Cellular biology; Complex; DNA Repair; Data; Detection; Development; Embryonic Development; Epithelial; Estrogen Receptor beta; Family; Future; Genetic Transcription; Growth; Homeodomain Proteins; Immune system; Immunocompetent; Infiltration; Malignant Neoplasms; Mammalian Cell; Mammary Neoplasms; Mass Spectrum Analysis; Mediating; Mesenchymal; Molecular; N-terminal; Neoplasm Metastasis; Phenocopy; Phenotype; Phosphoric Monoester Hydrolases; Protein Family; Protein Subunits; Protein phosphatase; Proteins; Regulation; Role; Structure; T cell response; T-Lymphocyte; Testing; Therapeutic Intervention; Time; Tissues; Transcriptional Activation; Tumor Escape; Tumor Immunity; Tumor Suppression; Tumor Suppressor Proteins; adaptive immunity; anti-tumor immune response; biophysical properties; cell fate specification; cell motility; checkpoint therapy; chemokine; cofactor; cytotoxic CD8 T cells; immune checkpoint; immunogenic; in vivo; inhibitor/antagonist; insight; knock-down; malignant breast neoplasm; migration; mouse model; mutant; new therapeutic target; novel; novel marker; novel therapeutic intervention; overexpression; phosphoproteomics; programmed cell death ligand 1; programmed cell death protein 1; protein phosphatase 2A regulatory subunit 65 kDa; recruit; response; triple-negative invasive breast carcinoma; tumor; tumor growth; tumor progression; tumor-immune system interactions

Abstract The Eya proteins (Eya 1-4) were initially discovered as essential co-activators of the Six family of homeoproteins that regulate embryonic development via controlling proliferation, survival, epithelial versus mesenchymal fates, and overall cell fate specification in numerous tissues. The Six/Eya complex is downregulated after development is complete, but is re-expressed in numerous cancers, including breast cancer. In addition to acting as transcriptional cofactors for the Six family of proteins, Eyas also contain a Tyr phosphatase activity in their C-terminal domains that has been implicated not only in transcriptional activation, but also in motility, DNA repair and survival in response to damage, angiogenesis, and inhibition of the anti- tumor activity of estrogen receptor-b. Currently, inhibitors are being developed against the transcriptional and Tyr phosphatase activities of Eyas to dissect its different functions, and to potentially develop anti-cancer agents. The Eyas also contain a Ser/Thr phosphatase activity in their N-terminal domain, that is completely separable from the Tyr phosphatase activity. The function of this activity in cancer is completely unknown and it is not targeted by any of the Eya inhibitors under development. Intriguingly, the N-terminal domain of Eya does not contain any recognizable phosphatase motifs and our data suggest that the Ser/Thr phosphatase activity of Eya is not intrinsic, but is instead due to an interaction with the protein phosphatase 2A (PP2A). In addition, using two different immune competent mouse models, we show for the first time that Eya3, which is overexpressed in triple negative breast cancers (TNBC) as compared to other subtypes, and contains the highest Ser/Thr phosphatase activity, influences tumor progression via its effects on adaptive immunity. We further demonstrate that Eya3, through its PP2A-associated Ser/Thr phosphatase activity, regulates the key immune checkpoint protein programmed death-ligand 1 (PD-L1). Thus, we identified a novel tumor promoting function for Eya3 that is only revealed in the context of a functional adaptive immune system. In this proposal we test the hypothesis that Eya3 regulates breast tumor growth and progression via its ability to recruit PP2A, leading to increased levels of PD-L1 and a diminished tumor specific T-cell response. Results obtained in this project will significantly advance our understanding of the role of Eya3 in breast tumor progression, and may also reveal that Eya3, through its previously unknown ability to interact with PP2A, is an important new player in adaptive tumor immunity. Further, we may uncover a novel regulatory mechanism of a key immune checkpoint protein, PD-L1, whose regulation has remained largely elusive. Thus our studies may result in novel biomarker or therapeutic strategies to enhance efficacy of PD-1/PD-L1 mediated therapies.

抽象的 Eya 蛋白 (Eya 1-4) 最初被发现是六家族的重要共激活剂。 通过控制增殖、存活、上皮细胞与上皮细胞来调节胚胎发育的同源蛋白 间充质命运，以及许多组织中的整体细胞命运规范。六/埃亚复合体是 发育完成后下调，但在多种癌症中重新表达，包括乳腺癌 癌症。除了作为 Six 蛋白家族的转录辅助因子外，Eyas 还含有 Tyr C 端结构域中的磷酸酶活性不仅与转录激活有关， 还包括对损伤、血管生成和抗-细胞因子抑制的反应的运动、DNA 修复和存活。 雌激素受体-b的肿瘤活性。目前，正在开发针对转录和 Eyas 酪氨酸磷酸酶活性，剖析其不同功能，并潜在开发抗癌药物 代理。 Eyas 的 N 末端结构域还包含 Ser/Thr 磷酸酶活性，这是完全可分离的 来自酪氨酸磷酸酶活性。这种活性在癌症中的作用是完全未知的，也不是 任何正在开发的 Eya 抑制剂的目标。有趣的是，Eya 的 N 端结构域并不 包含任何可识别的磷酸酶基序，我们的数据表明 Ser/Thr 磷酸酶活性 Eya 不是内在的，而是由于与蛋白磷酸酶 2A (PP2A) 的相互作用而产生的。此外， 使用两种不同的免疫能力小鼠模型，我们首次展示了 Eya3，即 与其他亚型相比，在三阴性乳腺癌 (TNBC) 中过度表达，并且包含 最高的丝氨酸/苏氨酸磷酸酶活性，通过其对适应性免疫的影响影响肿瘤进展。我们 进一步证明 Eya3 通过其 PP2A 相关的 Ser/Thr 磷酸酶活性，调节关键 免疫检查点蛋白程序性死亡配体 1 (PD-L1)。因此，我们发现了一种新的肿瘤促进剂 Eya3 的功能仅在功能性适应性免疫系统的背景下才被揭示。在这个提案中 我们测试了 Eya3 通过招募 PP2A 的能力来调节乳腺肿瘤生长和进展的假设， 导致 PD-L1 水平升高和肿瘤特异性 T 细胞反应减弱。 该项目获得的结果将显着促进我们对 Eya3 在乳腺肿瘤中作用的理解 进展，并且还可能揭示 Eya3 通过其先前未知的与 PP2A 相互作用的能力，是一种 适应性肿瘤免疫的重要新参与者。此外，我们可能会发现一种新的调节机制 关键的免疫检查点蛋白 PD-L1，其调控在很大程度上仍然难以捉摸。因此我们的研究可能 产生新的生物标志物或治疗策略，以增强 PD-1/PD-L1 介导的疗法的功效。