骨癌痛小鼠血清IGF-1和脊髓背角磷酸化IGF-1受体表达变化

Expression of IGF-1 in serum and phosphorylated IGF-1 receptor in spinal cord in mouse model of bone cancer pain

目的探讨骨癌痛小鼠血清胰岛素样生长因子-1（insulin-like growth factors-1，IGF-1）和脊髓背角磷酸化的IGF-1受体的表达变化。方法雄性C3H/HeJ小鼠60只，体质量18～22 g，采用随机数字表法，将其分假手术组（Sham组，n＝30）和骨癌痛组（Tumor组，n＝30）。Tumor组小鼠在右侧股骨远端骨髓腔接种NCTC纤维肉瘤细胞，建立骨癌痛模型。两组分别于肿瘤细胞接种前1 d、接种后4 d、7 d、10 d、14 d、21 d记录机械缩足阈值（PWMT）和自发抬足次数（NSF）（n＝8/组）。取4只小鼠进行眼球取血，术后14 d小鼠眼球取血后进行组织灌注取腰段脊髓。酶联免疫吸附法检测两组接种前1 d、接种后4 d、7 d、10 d、14 d、21 d血清中IGF-1的表达，免疫荧光法检测两组造模后14 d脊髓L3～5节段中磷酸化IGF-1受体蛋白的表达（每组n＝6）。结果与Sham组相比，Tumor组PWMT术后7～21 d降低（P〈0.05），NSF术后7～21 d增加（P〈0.05）。与基础值和Sham组比较[基础值（27.33±0.52）pg/ml、Sham组（29.11±1.86）pg/ml、（24.51±3.61）pg/ml、（23.33±4.59）pg/ml、（25.29±2.99）pg/ml]，Tumor组血清中IGF-1表达在术后7～21 d增高[（39.76±3.92）pg/ml、（36.93±2.18）pg/ml、（38.85±2.40）pg/ml、（39.70±2.62）pg/ml]（P〈0.05）。Tumor组术后14 d脊髓中磷酸化IGF-1受体免疫荧光强度[（2.40±0.11）]高于Sham组[（0.05±0.01）]（P〈0.05）。结论骨癌痛小鼠血清中IGF-1和脊髓背角磷酸化IGF-1受体表达增加，该变化可能参与了骨癌痛的发生和维持。

ObjectiveTo investigate the expression of insulin-like growth factors -1（IGF-1） in serum and phosphorylated IGF-1 receptor in spinal cord in mouse model of bone cancer pain.MethodsSixty male C3H/HeJ mice weighed 18-22 g were randomly divided into Sham group（n=30） and Tumor group（n=30）. The mice in Tumor group were inoculated with NCTC fibrosarcoma cells in the right femur bone marrow cavity. Paw withdrawl mechanical threshold（PWMT） and the number of spontaneous flinches（NSF） were measured on 1d before inoculation and on 4 d, 7 d, 10 d, 14 d, 21 d after inoculation（n=8）. At each time point, the mice of each group were taken blood by removal eyeball and the samples of blood were obtained to detect the expression of IGF-1 by enzyme-linked immunosorbent assay（n=4）. The mice after taken blood on 14 d after inoculation were perfused and the samples of spinal cord lumber（L3~5） segment were obtained to detect the expression of phosphorylated IGF-1 receptor by immunofluorescence assay（n=6）.ResultsCompared with Sham group, PWMT was significantly decreased（P〈0.05） and NSF was significantly increased（P〈0.05） on 7~21 d after inoculation. Compared with baseline value and Sham group（baseline value（27.33±0.52）pg/ml, Sham group（29.11±1.86）pg/ml, （24.51±3.61）pg/ml, （23.33±4.59）pg/ml, （25.29±2.99）pg/ml）, the expression of IGF-1 in serum was significantly increased on 7~21 d after inoculation in Tumor group（（39.76±3.92）pg/ml, （36.93±2.18）pg/ml, （38.85±2.40）pg/ml, （39.70±2.62）pg/ml）. The mean fluorescence intensity of phosphorylated IGF-1 receptor was significantly higher on 14d after inoculation in Tumor group（2.40±0.11） compared with Sham group（0.05±0.01）.ConclusionExpression of IGF-1 in serum and phosphorylated IGF-1 receptor in spinal cord were significantly increased in mice with bone cancer pain, and this change may be involved in the development and maintenance of bone cancer pain.