Neural Mechanisms of Cancer Pain

摘要 癌症疼痛的管理仍然是一个重大挑战。癌痛是一种复杂的疼痛 包括炎症、神经病变成分和一套独特的癌症特异性成分的状态 组件。癌细胞分泌的外切体是癌症特异性因子之一。在……里面 初步研究，由蛋白质标记的大小和表达证实的外切体，诱导 急性机械性和热敏性痛觉过敏 幼稚的C3H/母鸡小鼠。这个项目将检验这样一种假设，即外切体由 纤维肉瘤细胞通过敏化伤害性初级传入神经元产生疼痛。 自体趋化蛋白(ATX)-溶血磷脂酸(LPA)-LPA1受体(R)途径。分离的外切体 来自纤维肉瘤细胞的条件培养液将通过大小(纳米颗粒追踪)进行验证 分析)、外切体特异性标记的表达以及ATX的活性。电生理学 体内研究将确定ATX-LPA-LPA1R信号对外切体特异性的贡献 伤害性感受器的敏化。在细胞水平上，小背根的急性敏化 成年小鼠的神经节(DRG)神经元将在一项生物测试中定义，该生物测试将测量 25 mM氯化钾体外去极化时钙瞬变的发生 印多-1。纤维肉瘤细胞释放的外切体结合的ATX-LPA复合体 通过激活LPA1受体使DRG神经元增敏将使用 药理学和分子(SiRNA)方法。建议使用拆分蛋白d1来衰减 外切体对伤害性感受器的敏化和通过干扰ATX-LPA而引起的痛觉过敏 LPA1R信令。如果外切体介导的ATX-LPA-LPA1R信号是痛觉过敏的基础，它将 为管理骨癌疼痛的新策略提供洞察力。未来的研究将进一步 研究其分子、生化和电生理机制。 癌细胞释放的外切体与癌症疼痛有关。

ABSTRACT The management of cancer pain remains a major challenge. Cancer pain is a complex pain state that includes inflammatory, neuropathic components and a unique set of cancer-specific components. Exosomes secreted by cancer cells is one of those cancer-specific factors. In preliminary studies, exosomes confirmed by size and expression of protein markers, induced acute mechanical and heat hyperalgesia following injection into the hind paw of both sexes of naïve C3H/HeN mice. This project will test the hypothesis that exosomes secreted by fibrosarcoma cells produce pain by sensitizing nociceptive primary afferent neurons via the autotaxin (ATX)-lysophosphatidic acid (LPA)-LPA1 receptor (R) pathway. Exosomes isolated from fibrosarcoma cell-conditioned media will be verified by size (Nanoparticle tracking analysis), expression of the exosome-specific markers, and activity of ATX. Electrophysiological studies in vivo will determine the contribution of ATX-LPA-LPA1R signaling to exosome-specific sensitization of nociceptors. At the cellular level, acute sensitization of small dorsal root ganglion (DRG) neurons from adult mice will be defined in a bioassay that measures the occurrence of a calcium transient in response to depolarization with 25 mM KCl in vitro with Indo-1. Whether the exosome-bound ATX-LPA complex released from fibrosarcoma cells sensitizes DRG neurons through activation of LPA1 receptors will be determined using pharmacological and molecular (siRNA) approaches. Resolvin D1 is proposed to attenuate exosome-evoked sensitization of nociceptors and hyperalgesia by interfering with ATX-LPA- LPA1R signaling. If exosome-mediated ATX-LPA-LPA1R signaling underlies hyperalgesia, it will provide insight into a new strategy for managing bone cancer pain. Future studies will further investigate the molecular, biochemical and electrophysiological mechanisms by which exosomes released from cancer cells contribute to cancer pain.