Wang Dan, Yu Jianbo
Department of Anesthesiology, Tianjin Nankai Hospital, Tianjin Medical University, Tianjin, China.
Oncotarget. 2016 Dec 20;7(51):85564-85572. doi: 10.18632/oncotarget.9447.
In this study, C3H/HeNCrlVr mice are implanted with sarcoma NCTC 2472 cells into the intramedullary space of the femur to induce ongoing bone cancer-related pain behaviors. During the progress of the bone cancer pain, the down-regulation in spinal REST (Neuron-restrictive silencer factor, NRSF/REST) with concomitant up-regulation in spinal NR2B (2B subunit of N-methyl-D-aspartate receptor, NR2B) protein expression are observed at days 5, 7, 10 and 14 post-inoculation. Immunofluorescence assay shows that almost all of REST and NR2B-positive signals encompass NeuN (neuron-specific nuclear protein, a neuronal marker)-positive signals in spinal cord of sham and tumor-bearing mice. Different from previous researches involved in the main distribution of REST in neural progenitors, the expression of REST in mature neurons in spinal cord of adult mice is observed. Intrathecal administration of AS-ODN of REST at days 0, 2, 4 and 6 post-inoculation further enhances expression of spinal NR2B at day 7 post-inoculation, which suggests the reduced suppression of spinal REST on NR2B during the development of bone cancer pain. In summary, our study provides the evidence that the negative regulation of REST on NR2B in spinal cord takes part in the exacerbation of bone cancer pain.
在本研究中，将肉瘤NCTC 2472细胞植入C3H/HeNCrlVr小鼠的股骨骨髓腔内，以诱导持续的骨癌相关疼痛行为。在骨癌疼痛进展过程中，接种后第5、7、10和14天观察到脊髓中REST（神经元限制性沉默因子，NRSF/REST）下调，同时脊髓中NR2B（N-甲基-D-天冬氨酸受体2B亚基，NR2B）蛋白表达上调。免疫荧光分析显示，在假手术小鼠和荷瘤小鼠的脊髓中，几乎所有REST和NR2B阳性信号都包含NeuN（神经元特异性核蛋白，一种神经元标志物）阳性信号。与之前关于REST主要分布于神经祖细胞的研究不同，本研究观察到成年小鼠脊髓成熟神经元中存在REST表达。接种后第0、2、4和6天鞘内注射REST反义寡核苷酸（AS-ODN），进一步增强了接种后第7天脊髓NR2B的表达，这表明在骨癌疼痛发展过程中脊髓REST对NR2B的抑制作用减弱。总之，我们的研究提供了证据，表明脊髓中REST对NR2B的负调控参与了骨癌疼痛的加剧。
