Neural Mechanisms of Cancer Pain

摘要 癌症疼痛的管理仍然是一个重大挑战。癌症疼痛是一种复杂的疼痛 包括炎症，神经病变成分和一组独特的癌症特异性 件.由癌细胞分泌的外泌体是这些癌症特异性因子之一。在 初步研究，通过蛋白质标记物的大小和表达证实的外泌体，诱导 向两种性别动物的后爪注射以下物质后的急性机械和热痛觉过敏： C3 H/HeN小鼠。该项目将测试外泌体分泌的假设， 纤维肉瘤细胞通过致敏伤害性初级传入神经元产生疼痛， 自分泌运动因子（ATX）-溶血磷脂酸（LPA）-LPA 1受体（R）途径。分离的外来体 纤维肉瘤细胞条件培养基中的细胞将通过大小进行验证（纳米颗粒跟踪 分析）、外泌体特异性标志物的表达和ATX的活性。电生理 体内研究将确定ATX-LPA-LPA 1 R信号传导对外泌体特异性 伤害感受器的敏感化。在细胞水平上，小背根急性致敏 来自成年小鼠的神经节（DRG）神经元将在生物测定中被定义，该生物测定测量来自成年小鼠的神经节（DRG）神经元中的神经元。 在体外使用25 mM KCl对去极化反应的钙瞬变发生， Indo-1纤维肉瘤细胞是否释放了外泌体结合的ATX-LPA复合物 通过激活LPA 1受体使DRG神经元敏感的作用将使用 药理学和分子（siRNA）方法。建议使用Resolvin D1来减弱 外泌体通过干扰ATX-LPA引起的伤害感受器敏化和痛觉过敏 LPA 1 R信号传导。如果外泌体介导的ATX-LPA-LPA 1 R信号转导是痛觉过敏的基础，那么它将 提供了一个新的策略管理骨癌疼痛的见解。未来的研究将进一步 研究分子，生物化学和电生理机制， 癌细胞释放的外泌体导致癌症疼痛。

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.