125I粒子照射腹腔神经节调控相关miRNA表达在胰腺癌痛治疗中的作用机制研究

Pancreatic cancer commonly cause pain that is difficult to control，side effects of opioids can't be tolerated. Celiac ganglion neurolysis with alcohol has some effect for pain control. Our previous study showed that brachytherapy on celiac ganglia with 125I seeds had better and long-lasting analgesic effect which can not be simply explained by celiac ganglion neurolysis.We also found that 125I seed irradiation on pancreatic cancer cell lines can lead to changes of miRNAs expression. miRNA expression changes have been reported to play an important role in occurrence and maintenance of chronic neuropathic pain. So we speculate that celiac ganglion branchytherapy may cause changes of pain related miRNAs expression to play a role in pain control.In this study, celiac ganglion get from patients who received pancreatectomy for pancreatic cancer pain ,which be irradiated by 125I seeds to screen candidate miRNAs related to branchytherapy and pain.Then, the celiac ganglion cells will be cultured and transgenic intervented to observe the gene transfection on the biological behavior of celiac ganglion neurons, determine the candidate target genes of miRNAs. The infruence of candidate neuropathic pain related miRNAs on electrical activity will be tested by using patch-clamp technique. Finally,we will verify the analgesic effect of the intervention miRNAs target gene protein in an animal pain model. The aim of this study is to provide theoretical basis for the clinical application of brachytherapy on celiac ganglia with 125I seeds for pain control in patients who suffered from pancreatic cancer.

胰腺癌疼痛剧烈，吗啡类药物治疗副反应大，酒精注射损毁腹腔神经节（CG）有一定疗效。但是，我们前期研究发现低剂量率125I粒子植入照射CG疗效更佳且持久，此现象不能单纯用"毁损CG"来解释；研究还发现125I粒子照射胰腺癌细胞株可导致miRNAs表达变化；业已证实慢性神经病理性疼痛发生与部分miRNAs异常表达相关。因此推测粒子照射CG可导致疼痛相关miRNAs表达变化而发挥治疗效果。本研究拟以胰腺癌痛患者的CG作为实验材料，125I粒子照射干预，筛选出粒子照射可调控的疼痛相关候选miRNAs；而后，在原代培养的CG细胞中，转基因干预观察基因转染对CG神经元生物学行为的影响，并确定出候选miRNAs的靶基因；再运用膜片钳技术研究候选miRNAs对神经病理性疼痛相关电活动的影响；最后动物模型验证干预相关miRNAs靶基因蛋白的镇痛效果，为粒子植入照射CG治疗胰腺癌痛新技术临床推广提供理论依据。

背景：本研究从超声内镜下125I粒子种植缓解胰腺癌患者疼痛临床现象出发，在细胞、分子水平上探索放射粒子缓解疼痛的机制。.结果：细胞实验发现粒子辐照可以显著抑制大鼠背根神经节细胞（DRG）活力，并以剂量依赖性方式增加细胞坏死，125I 粒子轻度提高了cleaved caspase-9、cleaved caspase-8蛋白表达，显着抑制了Bcl-2，Bax蛋白表达；分子水平上发现125I粒子照射可通过miR-1246下调TRPV1表达从而抑制神经细胞生长；细胞膜片钳发miR-1246是通过抑制神经细胞内源性的NA+电流而缓解疼痛感觉。.结论：125I粒子照射可通过miR-1246下调TRPV1表达从而抑制神经细胞生长，介导神经细胞凋亡并通过抑制神经细胞内源性的NA+电流而缓解疼痛感觉。.科学意义：本研究阐明了125I粒子缓解胰腺癌患者疼痛一种新机制，为粒子植入照射 CG 治疗胰腺癌痛新技术临床推广提供理论依据。