Neural Mechanisms of Cancer Pain

摘要 癌症疼痛的治疗仍然是一个重大挑战。癌痛是一种复杂的疼痛 包括炎症、神经病理性成分和一组独特的癌症特异性的状态 组件。癌细胞分泌的外泌体是癌症特异性因子之一。在 初步研究，通过蛋白质标记的大小和表达证实了外泌体，诱导 注射到男女后爪后出现急性机械和热痛觉过敏 幼稚 C3H/HeN 小鼠。该项目将检验以下假设：外泌体由 纤维肉瘤细胞通过使伤害性初级传入神经元敏感来产生疼痛 自分泌运动因子 (ATX)-溶血磷脂酸 (LPA)-LPA1 受体 (R) 途径。分离的外泌体 来自纤维肉瘤细胞条件培养基的细胞将通过尺寸进行验证（纳米粒子追踪 分析）、外泌体特异性标记物的表达以及 ATX 的活性。电生理学 体内研究将确定 ATX-LPA-LPA1R 信号传导对外泌体特异性的贡献 伤害感受器的敏化。在细胞水平上，小背根的急性敏化 来自成年小鼠的神经节（DRG）神经元将在生物测定中被定义，该测定测量 体外 25 mM KCl 去极化反应中发生钙瞬变 印度-1。纤维肉瘤细胞是否释放外泌体结合的 ATX-LPA 复合物 通过激活 LPA1 受体使 DRG 神经元敏感将使用以下方法确定 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- 诱发伤害感受器敏化和痛觉过敏 LPA1R 信号传导。如果外泌体介导的 ATX-LPA-LPA1R 信号是痛觉过敏的基础，那么它将 提供对治疗骨癌疼痛的新策略的见解。未来的研究将进一步 研究分子、生化和电生理机制 癌细胞释放的外泌体会导致癌症疼痛。

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.