The Role of Peroxiredoxin1 & Reactive Oxygen Species in Breast Tumor Initiation

过氧化还原蛋白1的作用

基本信息

批准号：
8625187
负责人：
CAROLA ANKE NEUMANN
金额：
$ 29.94万
依托单位：
UNIVERSITY OF PITTSBURGH AT PITTSBURGH
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-04-07 至 2015-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8625187
关键词：
Agar Aging Alleles Antioxidants Apoptosis Binding Bioluminescence Breast Breast Epithelial Cells Cancer Etiology Catalytic Domain Cell Proliferation Cell Transplants Cells Complex Cysteine Development Environmental Carcinogens Exhibits Family Fatty acid glycerol esters Fibroblasts Future Growth Factor HRAS gene Hemolytic Anemia Human Hydrogen Peroxide In Vitro Incidence Induction of Apoptosis Investigation Ionizing radiation Lipids Malignant Neoplasms Mammary Neoplasms Mediating Membrane Membrane Potentials Mouse Mammary Tumor Virus Mus Mutation Nuclear Nuclear Localization Signal Nude Mice PTEN gene PTEN protein Peptide Signal Sequences Peptides Peroxidases Phosphatidylinositols Phosphoric Monoester Hydrolases Phosphorylation Phosphotransferases Play Predisposition Preventive Process Protein Dephosphorylation Puma Reactive Oxygen Species Regulation Role Signal Pathway Signal Transduction Testing Tobacco smoking Tumor Burden Tumor Suppression Tumor Suppressor Proteins Work base cell transformation cell type in vivo insight malignant breast neoplasm mitochondrial membrane mouse model novel oxidation prevent public health relevance radiation carcinogen tool tripolyphosphate tumor tumor initiation tumorigenesis

项目摘要

DESCRIPTION (provided by applicant): It is widely accepted that reactive oxygen species (ROS), such as H2O2 promote tumorigenesis. Consequently, there is a crucial need for a greater understanding of the mechanism of H2O2-mediated cancer development. We have shown that mice lacking one or two copies of the peroxidase Prdx1 die prematurely of hemolytic anemia and multiple cancers. Furthermore, cells and mice lacking Prdx1 show a higher incidence of transformation to H-RasV12 and ErbB-2 and H-RasV12-induced breast cancer. Fibroblasts and mammary epithelial cells lacking Prdx1 show higher phosphorylation of Akt on Ser473 and more inactive (oxidized) forms of the tumor suppressor PTEN. PTEN is readily inactivated via oxidation of the low pKa cysteine in its catalytic site. We found that Prdx1 binding to PTEN is essential to protect it from oxidation-induced inactivation. The Prdx1:PTEN complex is disrupted by H2O2, upon which Akt including its downstream signaling is activated resulting in a decrease in apoptosis. Therefore, our working hypothesis is that H2O2 inactivates PTEN lipid phosphatase activity due to a complex disruption of Prdx1:PTEN, thereby promoting Akt kinase-driven oncogenesis. We further hypothesize that Prdx1:PTEN binding is required for normal PTEN function, including its lipid phosphatase activity, nuclear stability and apoptosis induction. Specific Aim1 will determine the mechanisms by which H2O2 regulates the Prdx1:PTEN interaction to alter PTEN lipid phosphatase activity and Prdx1 peroxidase activity. We will define if H2O2-induced oxidation of either Prdx1 or PTEN disrupts or prevents the Prdx1:PTEN interaction and modulates PTEN lipid phosphatase activity and Prdx1 peroxidase activity. Specific Aim2 will examine if the Prdx1:PTEN interaction promotes tumor suppression by regulating PTEN or Akt dependent mechanisms. To complete this we will examine PTEN-induced tumor suppressive functions including apoptosis upon disrupting the Prdx1:PTEN interactions by using peptide interference in vitro and in vivo. Specific Aim3 will evaluate if nuclear Prdx1 promotes tumor suppression ErbB-2-induced breast cancer in mice. We have found that loss of Prdx1 decreases nuclear PTEN protein levels. We will therefore introduce Prdx1 fused to nuclear localization signal sequence into mammary epithelial cells isolated from Prdx1-/-MMTV-ErbB-2 mice and transplant cells into clear fad pads of NCR nude mice, to observe if nuclear Prdx1 decreases incidence of breast cancer or tumor burden. Mice lacking Prdx1 offer the first mouse model where loss of a peroxidase results in elevation of endogenous H2O2 thereby causing cancer. This mouse model mimics conditions where H2O2 levels are elevated as found in aging, tobacco smoking, ionizing radiation and environmental carcinogens. By studying breast cancer prone mice lacking Prdx1 we should help to find more specific preventive treatments in H2O2-induced breast cancer.

描述（由申请人提供）：人们普遍认为活性氧（ROS），例如H2O2，会促进肿瘤发生。因此，迫切需要更好地了解 H2O2 介导的癌症发展机制。我们已经证明，缺乏一两个过氧化物酶 Prdx1 拷贝的小鼠会因溶血性贫血和多种癌症过早死亡。此外，缺乏Prdx1的细胞和小鼠表现出更高的转化为H-RasV12和ErbB-2以及H-RasV12诱导的乳腺癌的发生率。缺乏 Prdx1 的成纤维细胞和乳腺上皮细胞在 Ser473 上表现出较高的 Akt 磷酸化，以及肿瘤抑制因子 PTEN 的非活性（氧化）形式。 PTEN 很容易通过其催化位点中的低 pKa 半胱氨酸的氧化而失活。我们发现 Prdx1 与 PTEN 的结合对于保护其免受氧化诱导的失活至关重要。 Prdx1:PTEN 复合物被 H2O2 破坏，Akt 及其下游信号传导被激活，导致细胞凋亡减少。因此，我们的工作假设是，由于 Prdx1:PTEN 的复杂破坏，H2O2 使 PTEN 脂质磷酸酶活性失活，从而促进 Akt 激酶驱动的肿瘤发生。我们进一步假设 Prdx1:PTEN 结合是正常 PTEN 功能所必需的，包括其脂质磷酸酶活性、核稳定性和细胞凋亡诱导。具体的 Aim1 将确定 H2O2 调节 Prdx1:PTEN 相互作用以改变 PTEN 脂质磷酸酶活性和 Prdx1 过氧化物酶活性的机制。我们将定义 H2O2 诱导的 Prdx1 或 PTEN 氧化是否会破坏或阻止 Prdx1:PTEN 相互作用并调节 PTEN 脂质磷酸酶活性和 Prdx1 过氧化物酶活性。具体的 Aim2 将检查 Prdx1:PTEN 相互作用是否通过调节 PTEN 或 Akt 依赖机制来促进肿瘤抑制。为了完成这一任务，我们将在体外和体内使用肽干扰来检查 PTEN 诱导的肿瘤抑制功能，包括破坏 Prdx1:PTEN 相互作用时的细胞凋亡。具体的 Aim3 将评估核 Prdx1 是否促进肿瘤抑制 ErbB-2 诱导的小鼠乳腺癌。我们发现 Prdx1 的缺失会降低核 PTEN 蛋白水平。因此，我们将融合核定位信号序列的Prdx1导入从Prdx1-/-MMTV-ErbB-2小鼠分离的乳腺上皮细胞中，并将细胞移植到NCR裸鼠的透明fad垫中，观察核Prdx1是否会降低乳腺癌的发病率或降低乳腺癌的发生率。肿瘤负荷。缺乏 Prdx1 的小鼠提供了第一个小鼠模型，其中过氧化物酶的缺失导致内源性 H2O2 升高，从而导致癌症。该小鼠模型模拟了衰老、吸烟、电离辐射和环境致癌物中 H2O2 水平升高的情况。通过研究缺乏 Prdx1 的乳腺癌易感小鼠，我们应该有助于找到针对 H2O2 诱发的乳腺癌的更具体的预防治疗方法。