GAP JUNCTION INTERCELLULAR COMMUNICATION AND POLYAMINES

间隙连接细胞间通讯和多胺

• 批准号: 8704953
• 负责人: YURIY KUCHERYAVYKH
• 金额: $ 14.23万
• 依托单位: UNIVERSIDAD CENTRAL DEL CARIBE
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-01 至 2016-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8704953
• 关键词: Antiviral Agents; Astrocytes; Attention; Binding; Bystander Effect; Cell surface; Cells; Charge; Chemosensitization; Communication; Connexin 43; Connexins; Coupled; Cytoplasm; DL-alpha-Difluoromethylornithine; Data; Dependence; Dose; Enzymes; Fluorescent Dyes; Ganciclovir; Gap Junctions; Glioblastoma; Glioma; HSV-Tk Gene; Hela Cells; Hippocampus (Brain); Human; Knockout Mice; Knowledge; Link; Malignant - descriptor; Malignant Neoplasms; Malignant neoplasm of brain; Neuroglia; Normal Cell; Ornithine Decarboxylase; Pathway interactions; Point Mutation; Polyamines; Probability; Putrescine; Regulation; Signal Transduction; Slice; Spermidine; Spermine; Techniques; Testing; Western Blotting; base; cancer cell; cancer therapy; glioma cell line; human GJB2 protein; intercellular communication; lucifer yellow; overexpression; public health relevance; response; tumor microenvironment

DESCRIPTION (provided by applicant): Gliomas are tumors of glial cell origin, with glioblastoma multiforme being one of the most aggressive forms of brain cancer. Unlike normal glia, glioma cells express low levels of functional connexin (Cx) hemichannel/gap junction protein and high levels of polyamines (PA). A lot of attention in the anti-cancer strategies focuses on either (i) PA or (ii) Cxs, although there is not very much known about how PA and Cx hemichannels/gap- junctions co-interact. Expression of Cx in glioma cells is found predominantly in the cytoplasm with very little cell surface expression. In spite of this, there is still highly functional gap junctional intercellular communication between glioma cells. It is unclear how low levels of cell surface Cx expression allow such high gap junctional intercellular communication between glioma cells. Our preliminary data indicate that (1) PA eliminate cationic block of Cx43 gap junctions/hemichannels and (2) increase their open probability. Based on these findings, we hypothesize that high levels of PA present in glioma cells potentiate Cx43 channel opening and enhance gap junctional intercellular communication. As a result, propagation of the intercellular signals through Cx43 gap junctions/hemichannels will be elevated. On the other hand, it was recently shown that intracellular PA block Cx40 gap junctions demonstrating a different effect of PA on different types of Cxs. Currently, there is no data about PA and Cxs (other than Cx43) in glial cells. The present study will examine the interaction between polyamines and Cx hemichannels/gap junctions in normal and malignant glia. To test our hypothesis we propose the following specific aims: Specific Aim 1: To determine the polyamine dependence of connexin hemichannel currents and gap junction communication in astrocytes, Cxs transfected cells and Cx43 conditional knock-out mice. Specific Aim 2: To determine how different types of Cxs overexpressed in glioma cells participate in gap junction intercellular communication and may contribute during cancer treatment. Significance: The results of these studies will provide a link between two targets of anti-cancer therapy; connexins and polyamines. We will define the effects polyamines on the different Cxs. This knowledge will help us to develop an effective strategy to treat cancer cells when the levels of PA are elevated. By regulation of Cxs, we can modulate gap junctional intercellular communication between glioma cells and potentially communication between glioma cells and the normal astrocytes in the tumor microenvironment.

描述（由申请人提供）：神经胶质瘤是神经胶质细胞来源的肿瘤，其中多形性胶质母细胞瘤是最具侵袭性的脑癌形式之一。与正常神经胶质细胞不同，神经胶质瘤细胞表达低水平的功能性连接蛋白（Cx）半通道/间隙连接蛋白和高水平的多胺（PA）。抗癌策略中的很多注意力都集中在 (i) PA 或 (ii) Cxs 上，尽管人们对 PA 和 Cx 半通道/间隙连接如何相互作用知之甚少。神经胶质瘤细胞中 Cx 的表达主要在细胞质中，细胞表面表达很少。尽管如此，还是有 神经胶质瘤细胞之间仍然具有高度功能性的间隙连接细胞间通讯。目前尚不清楚低水平的细胞表面 Cx 表达如何允许神经胶质瘤细胞之间如此高的间隙连接细胞间通讯。我们的初步数据表明 (1) PA 消除了 Cx43 间隙连接/半通道的阳离子阻断，并且 (2) 增加了它们的开放概率。基于这些发现，我们假设神经胶质瘤细胞中存在的高水平 PA 会增强 Cx43 通道的开放并增强间隙连接细胞间通讯。因此，细胞间信号通过 Cx43 间隙连接/半通道的传播将会增强。另一方面，最近的研究表明，细胞内 PA 阻断 Cx40 间隙连接，表明 PA 对不同类型的 Cxs 具有不同的作用。目前，没有关于胶质细胞中 PA 和 Cxs（Cx43 除外）的数据。本研究将检查正常和恶性神经胶质细胞中多胺和 Cx 半通道/间隙连接之间的相互作用。为了检验我们的假设，我们提出以下具体目标： 具体目标 1：确定星形胶质细胞、Cxs 转染细胞和 Cx43 条件敲除小鼠中连接蛋白半通道电流和间隙连接通讯的多胺依赖性。具体目标 2：确定神经胶质瘤细胞中过表达的不同类型的 Cxs 如何参与间隙连接细胞间通讯，并可能在癌症治疗过程中发挥作用。意义：这些研究的结果将提供抗癌治疗的两个目标之间的联系；连接蛋白和多胺。我们将定义多胺对不同 Cx 的影响。这些知识将帮助我们制定一种有效的策略，在 PA 水平升高时治疗癌细胞。通过调节 Cxs，我们可以调节神经胶质瘤细胞之间的间隙连接细胞间通讯，以及神经胶质瘤细胞与肿瘤微环境中正常星形胶质细胞之间的潜在通讯。