PMCA2 regulates mammary gland involution

PMCA2 调节乳腺复旧

• 批准号: 8836562
• 负责人: John J Wysolmerski
• 金额: $ 33.39万
• 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/8836562
• 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; Health; 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; 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（由申请方提供）：质膜钙ATP酶2（PMCA 2）将钙转运到乳汁中，并在泌乳后退化期间调节乳腺上皮细胞（MEC）死亡。此外，乳腺癌中的PMCA 2表达与患者生存率呈负相关。NHERF 1是一种支架分子，其利用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传导复合物。我们现在已经产生了相当多的初步数据，表明PMCA 2与NHERF 1和ErbB 2/HER 2/Neu（HER 2）相互作用，以调节哺乳期间MEC的存活和HER 2信号传导。初步数据还表明，PMCA 2表达的遗传操作深刻影响HER 2介导的肿瘤形成。我们的总体假设是，PMCA 2，NHERF 1和HER 2在哺乳期间形成一种功能复合物，需要将钙从MEC中转运出来，维持HER 2信号传导的活性并防止MEC过早死亡。我们认为，断奶后，扩张的MEC在牛奶淤滞的反应破坏了这一复杂的，这导致细胞内钙离子的增加和抑制HER 2信号，这两者联合收割机激活溶酶体通透性（LMP）的MEC死亡途径。最后，我们提出PMCA 2/NHERF 1/HER 2复合物在恶性转化过程中重新表达并激活HER 2信号传导，支持新出现的癌细胞的存活并推动HER 2阳性乳腺癌的进展。为了验证这一假设，我们提出了四个具体目标。目的1将研究PMCA 2，NHERF 1和HER 2是否在哺乳期间的多蛋白复合物内相互作用，以及早期退化期间的乳汁停滞是否会破坏该复合物。目的2将研究PMCA 2是否调节哺乳期和退化期间细胞死亡和HER 2活性的钙-钙蛋白酶-LMP通路。目的3将检查NHERF 1的丢失是否通过激活LMP通路和抑制退化期间的HER 2活性来模拟PMCA 2的丢失。目的4将检查PMCA 2和/或NHERF 1是否调节小鼠中HER 2介导的肿瘤形成。这些研究将推进我们对细胞死亡的LMP途径的了解，将帮助我们更好地了解乳汁淤积如何启动乳房退化，并将为哺乳期间和恶性转化期间HER 2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HER 2阳性乳腺癌潜在新治疗靶点的新途径。