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

Abstract

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 α 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 significantly 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. Key words: Bone neoplasms; Spinal cord; Gene silencing