骨癌痛小鼠脊髓神经元限制性沉默因子表达的变化

Changes in expression of neuron-restrictive silencer factor in spinal cord of mice with bone cancer pain

目的 评价骨癌痛小鼠脊髓神经元限制性沉默因子（NRSF）表达的变化。方法 清洁级成年雄性C3H/HeJ小鼠48只，4～6周龄，体重20～25 g，采用随机数字表法分为2组（n＝24）：假手术组（S组）和骨癌痛组（BCP组）。将含2×105个NCTC2472纤维肉瘤细胞的混悬液接种至小鼠右侧股骨远端骨髓腔制备小鼠骨癌痛模型。于接种后5、7、10和14 d（T1～4）时测定机械痛阈和热痛阈。于T1～4时测定痛阈后各组随机处死6只小鼠取脊髓腰膨大，检测NRSF的表达。结果 与S组比较，BCP组T2～4时机械痛阈、T3，4时热痛阈降低，T1～4时脊髓NRSF表达下调（P〈0.05）。结论 小鼠骨癌痛形成的机制可能与脊髓NRSF表达下调有关。

Objective To evaluate the changes in the expression of neuron-restrictive silencer factor （NRSF） in the spinal cord of mice with bone cancer pain. Methods Forty-eight pathogen-free adult male C3H/HeJ mice, aged 4-6 weeks, weighing 20-25 g, were randomly divided into 2 groups （n= 24 each） using a random number table： sham operation group （group S） and bone cancer pain group （group BCP）. Bone cancer pain was induced by injecting 2×105 NCTC2472 osteolytic sarcoma cells in a minimal essential medium into the medullary cavity of the right distal femur in group BCP. Only α minimal essential medium was injected into the medullary cavity of the right distal femur in group S. The mechanical and thermal pain thresholds were measured on 5, 7, 10 and 14 days after inoculation （T1-4）. Six mice in each group were randomly selected after measurement of pain thresholds at T1-4 and sacrificed, and the lumbar enlargement segments of the spinal cord were harvested to detect the expression of NRSF. Results Compared with group S, the mechanical pain threshold at T2-4 and thermal pain threshold at T3,4 were significanly decreased, and the expression of NRSF was significantly down-regulated at T1-4 in group BCP （P〈 0.05）. Conclusion The mechanism underlying the development of bone cancer pain is probably related to down-regulation of NRSF expression in the spinal cord of mice.