THE ROLE OF JAM-A IN CANCER METASTASIS AND SPERMATOGENESIS

该子项目是利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 中心，不一定是研究者的机构。 细胞-细胞连接在生理过程中很重要，紧密连接有助于维持保护多细胞生物免受环境影响的上皮细胞层。 参与形成这些连接的细胞表面粘附蛋白在导致细胞迁移的附着丧失中起作用。 我们已经确定并表征了一种新的细胞粘附分子，连接粘附分子-A（JAM-A），它在内皮细胞和上皮细胞紧密连接处表达。 我们的研究结果表明JAM-A参与了导致迁移行为的事件，包括癌细胞转移以及生育力低下。 因此，我们提出以下假设：1）乳腺癌细胞的转移行为与JAM-A的表达水平有关。 我们将确定JAM-A在具有一系列转移潜能的乳腺癌细胞系中的表达。 我们将比较JAM-A的表达与转移潜力，并使用细胞和小鼠模型来证实这种关系。 2)JAM-A的翻译后修饰影响乳腺癌细胞的转移能力 我们将确定JAM-A的翻译后修饰是否与这些细胞的转移行为有关。 同样，我们将利用体外以及体内肿瘤转移模型。 3)通过JAM-A的信号传导调节乳腺癌细胞的转移潜力。 将表征通过JAM-A诱导的细胞内信号传导途径。 4)JAM-A的表达减少和/或翻译后修饰影响精子发生，导致精子在头部和鞭毛上缺乏蛋白质。因此，存在降低的运动性和信号转导和蛋白质磷酸化性质的破坏。我们将确定在获能和未获能精子中缺乏JAM-A对基础细胞内钙的影响，以确定其在钙信号传导中的作用，该钙信号传导参与进行性和超活化运动。我们还将确定JAM-A是否存在于与质膜钙ATP酶4（PMCA 4）和钙丝氨酸激酶（CASK）（鞭毛信号分子）的多蛋白信号复合物中。我们的研究结果将有助于确定JAM-A在癌细胞转移和精子活力降低导致的男性生育力低下中的作用，并可以确定治疗靶点。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Cell-cell junctions are important in physiological processes, with tight junctions helping to maintain the epithelial cell layer that protects multicellular organisms from the environment. Cell surface adhesion proteins involved in forming these junctions play a role in the loss of attachment, which leads cells to become migratory. We have identified and characterized a novel cell adhesion molecule, Junctional Adhesion Molecule-A (JAM-A), which is expressed at endothelial and epithelial cell tight junctions. Our results implicate JAM-A in the events leading to migratory behavior, including cancer cell metastasis, as well as in subfertility. We therefore propose to test the following hypotheses in this proposal: 1) Metastatic behavior of breast cancer cells is related to the expression level of JAM-A. We will determine the expression of JAM-A in breast cancer cell lines with a range of metastatic potentials. We will compare the expression of JAM-A to the metastatic potential, and use cellular and mouse models to confirm the relationship. 2) Post-translational modifications of JAM-A influence the metastatic ability of breast cancer cells. We will determine if post-translational modification of JAM-A is related to the metastatic behavior of these cells. Again we will utilize in vitro, as well as in vivo, models of tumor metastasis. 3) Signaling through JAM-A regulates the metastatic potential of breast cancer cells. The intracellular signaling pathway induced through JAM-A will be characterized. 4) Reduced expression and/or post-translational modification of JAM-A affect spermiogenesis leading to sperm lacking the protein on the heads and the flagellum. Consequently, there is reduced motility and disruption of the signal transduction and protein phosphorylation properties. We will determine the effect of the absence of JAM-A on basal intracellular calcium in both capacitated and uncapacitated sperm to determine its role in calcium signaling which is involved in both progressive and hyperactivated motility. We will also determine if JAM-A is present in a multi-protein signaling complex with Plasma membrane calcium ATPase4 (PMCA4) and Calcium serine kinase (CASK) which are flagellar signaling molecules. Our results will help define the role of JAM-A in cancer cell metastasis and male subfertility resulting from reduced sperm motility, and can identify therapeutic targets.