Myostatin基因在荷瘤裸鼠腓肠肌组织中的表达

Expression of Myostatin in Gastrocnemius Muscle of Cancer Cachexia Mice Model

目的研究荷瘤裸鼠腓肠肌组织肌肉生长抑制素(myostatin)基因表达情况,观察美洛昔康对基因表达的影响及其对恶病质状况的改善作用。方法24只BALB/c裸鼠随机分三组(n=8),对照组(A组)、荷瘤+生理盐水治疗组(B组)、荷瘤+美洛昔康5 mg/kg治疗组(C组)。结肠癌Lovo细胞株皮下成瘤诱导肿瘤恶病质,RT-PCR及免疫组化法检测腓肠肌组织中myo-statin基因表达;对血清TNF-α水平与myostatin基因表达进行相关性分析。结果B组体质量为A组的60%,平均摄食量明显下降;血清TNF-α水平显著升高(均P<0.01)。C组体质量及腓肠肌质量显著高于B组;血清TNF-α水平显著降低(均P<0.01)。B组myostatin基因表达高于A组和C组(P<0.01),其表达量与血清TNF-α水平呈正相关(r=0.5438,P=0.006)。结论荷瘤裸鼠腓肠肌组织myostatin基因表达明显增高;美洛昔康能降低荷瘤裸鼠血清TNF-α水平,减少腓肠肌组织中myosta-tin基因表达水平,改善其恶病质状况。

Objective To study the expression level of myostatin in the gastrocnemius muscle of cancer cachexia mice and to observe the improvement of the status and the influence on myostatin expression by use of meloxicam. Methods The tumor-bearing cachexia mice model was established by Lovo cell line subcutaneous inoculation. Twenty-four BALB/c mice were randomly divided into 3 groups （ n = 8 for each group） ： group A, control ; group B, tumorbearing mice plus saline; group C, tumor-bearing mice plus meloxicam （5 mg/kg）. The food intake and body composition were documented. The expression of myostatin in the gastrocnemius muscle was investigated by RT-PCR and immunohistochemistry in all the animals, and the correlation analysis between serum TNF-α and myostatin was conducted. Results The body weight of group B was about 60% of group A, and the average food intake was significantly declined（P 〈0.01 ） , while there was a significant increase in serum TNF-α levels （P 〈0.01 ）. The body and gastrocnemius muscle weights of group C were significantly higher than those of group B （P 〈 0.01 ） , and the concentration of TNF-α was reduced（P 〈 0.01 ）. The expression of myostatin gene in group B was increased in comparison with group A and group C （P 〈 0.01 ） , and positive liner correlation was found between the expression of myostatin and TNF-α levels （r = 0. 5438 ,P =0. 006）. Conclusion Meloxicam may reduce the serum TNF-α levels and inhibit the expression of myostatin simultaneously. Thus, it can be used to alleviate the cachexia.