PMCA2 regulates mammary gland involution

PMCA2 调节乳腺复旧

• 批准号: 8725889
• 负责人: John J Wysolmerski
• 金额: $ 35.9万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-10 至 2019-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8725889
• 关键词: Actins; Affect; Apical; Automobile Driving; Biology; Breast; Breast Cancer Cell; Breast Epithelial Cells; Ca(2+)-Transporting ATPase; Calcium; Calpain; Cell Death; Cell Membrane Permeability; Cell Survival; Cells; Co-Immunoprecipitations; Complex; Cytoskeleton; Data; ERBB2 gene; Epithelial Cells; Fluorescence Resonance Energy Transfer; HER2 inhibition; Immunofluorescence Immunologic; Ion Channel; Ion Pumps; Knowledge; Lactation; Malignant - descriptor; Mammary gland; Mediating; Milk; Mouse Mammary Tumor Virus; Mus; PMCA1 protein; Pathway interactions; Patients; Permeability; Proteins; Receptor Protein-Tyrosine Kinases; Regulation; Signal Transduction; Stretching; Supporting Cell; Surface; Techniques; Testing; Weaning; cancer cell; genetic manipulation; insight; malignant breast neoplasm; new therapeutic target; novel; overexpression; premature; prevent; protein complex; public health relevance; receptor; response; scaffold; tumor

DESCRIPTION (provided by applicant): The plasma membrane calcium ATPase 2 (PMCA2) transports calcium into milk and regulates mammary epithelial cell (MEC) death during post-lactation involution. Furthermore, PMCA2 expression in breast cancers correlates inversely with patient survival. NHERF1 is a scaffolding molecule that utilizes PDZ- motif interactions to connect ion channels, ion pumps and receptors to the actin cytoskeleton in order to facilitate signaling complexes at the apical surface of epithelial cells. We now have generated considerable preliminary data showing that PMCA2 interacts with NHERF1 and ErbB2/HER2/Neu (HER2) to regulate MEC survival and HER2 signaling during lactation. Preliminary data also suggest that genetic manipulation of PMCA2 expression profoundly affects HER2-mediated tumor formation. Our overarching hypothesis is that PMCA2, NHERF1 and HER2 form a functional complex during lactation that is required to transport calcium out of MECs, to maintain active HER2 signaling and to prevent premature MEC death. We propose that, after weaning, distension of the MECs in response to milk stasis disrupts this complex, which causes an increase in intracellular calcium and an inhibition of HER2 signaling, both of which combine to activate the lysosomal permeability (LMP) pathway of MEC death. Finally, we propose that the PMCA2/NHERF1/HER2 complex is re-expressed and activates HER2 signaling during malignant transformation, supporting the survival of emerging cancer cells and driving the progression of HER2-positive breast cancers. In order to test this hypothesis, we propose 4 specific aims. Aim 1 will examine whether PMCA2, NHERF1 and HER2 interact within a multi-protein complex during lactation and whether milk stasis during early involution disrupts this complex. Aim 2 will examine whether PMCA2 regulates a calcium-calpain-LMP pathway of cell death and HER2 activity during lactation and involution. Aim 3 will examine whether loss of NHERF1 mimics loss of PMCA2 by activating the LMP pathway and inhibiting HER2 activity during involution. Aim 4 will examine whether PMCA2 and/or NHERF1 regulate HER2-mediated tumor formation in mice. These studies will advance our knowledge of the LMP pathway of cell death, will help us better understand how milk stasis initiates mammary involution and will provide new insight into the regulation of HER2 expression, localization and signaling during lactation and during malignant transformation. Finally, our studies will validate novel pathway for potential new therapeutic targets in HER2-positive breast cancer.

描述（由申请人提供）：质膜钙 ATP 酶 2 (PMCA2) 将钙转运到乳汁中，并在哺乳后复旧过程中调节乳腺上皮细胞 (MEC) 死亡。此外，乳腺癌中 PMCA2 的表达与患者的生存率呈负相关。 NHERF1 是一种支架分子，利用 PDZ 基序相互作用将离子通道、离子泵和受体连接到肌动蛋白细胞骨架，以促进上皮细胞顶端表面的信号复合物。我们现在已经生成了大量初步数据，表明 PMCA2 与 NHERF1 和 ErbB2/HER2/Neu (HER2) 相互作用，调节哺乳期间 MEC 的存活和 HER2 信号传导。初步数据还表明，PMCA2 表达的基因操作深刻影响 HER2 介导的肿瘤形成。我们的总体假设是，PMCA2、NHERF1 和 HER2 在哺乳期间形成一种功能复合物，需要将钙转运出 MEC，以维持活跃的 HER2 信号传导并防止 MEC 过早死亡。我们认为，断奶后，MEC 因乳汁停滞而膨胀，会破坏这种复合体，导致细胞内钙增加和 HER2 信号传导抑制，两者结合激活 MEC 死亡的溶酶体通透性 (LMP) 途径。最后，我们提出 PMCA2/NHERF1/HER2 复合物在恶性转化过程中重新表达并激活 HER2 信号传导，支持新兴癌细胞的存活并驱动 HER2 阳性乳腺癌的进展。为了检验这一假设，我们提出了 4 个具体目标。目标 1 将检查哺乳期间 PMCA2、NHERF1 和 HER2 是否在多蛋白复合物中相互作用，以及复旧早期的乳汁停滞是否会破坏该复合物。目标 2 将检查 PMCA2 是否调节哺乳期和复旧期间细胞死亡的钙-钙蛋白酶-LMP 途径和 HER2 活性。目标 3 将检查 NHERF1 的丢失是否通过激活 LMP 通路并在复旧过程中抑制 HER2 活性来模拟 PMCA2 的丢失。目标 4 将检查 PMCA2 和/或 NHERF1 是否调节小鼠中 HER2 介导的肿瘤形成。这些研究将增进我们对细胞死亡 LMP 途径的了解，帮助我们更好地了解乳汁停滞如何启动乳房复旧，并将为哺乳期间和恶性转化期间 HER2 表达、定位和信号传导的调节提供新的见解。最后，我们的研究将验证 HER2 阳性乳腺癌潜在新治疗靶点的新途径。