甲状旁腺激素(1-34)对小鼠肺癌骨转移瘤生长的影响

Effect of parathyroid hormone(1-34) on bone metastasis of lung cancer cells in mice

目的通过建立肺癌骨转移小鼠模型,探讨甲状旁腺激素（PTH）（1-34）对小鼠肺癌骨转移瘤生长的影响。方法将30只4~6周龄BALB/c雌性小鼠,用人肺癌A549细胞悬液骨内注射的方法制作胫骨近端肺癌骨转移模型,7 d后X线确定模型建立,随机分成3组,一组注射甲状旁腺素（PTH）（1-34）（40 mg/kg）作为观察组,一组注射等量溶解剂作为空白对照组,一组注射环磷酰胺作为阳性对照组,每2 d测体质量一次及观察右后肢瘤体生长情况,给药28 d后处死小鼠,所有小鼠行X线及显微CT检查观察肿瘤形态、大小,CT检测胫骨局部骨密度及肿瘤体积,HE染色及免疫组织化学法观察肿瘤形态及性质,检测血清碱性磷酸酶浓度了解成骨情况。所有数据采用SPSS 13.0统计软件进行分析,体质量以均数±标准差表示,ALP、肿瘤体积及CT数据分析采用单因素方差分析做整体检验,两两比较采LSD-t检验,P〈0.05被认为差异有统计学意义。结果观察组小鼠体质量变化曲线与对照组组间差异无显著性（P〉0.05）,X线及显微CT可见观察组及对照组均出现明显的骨破坏缺损,环磷酰胺组骨皮质相对完整,轻度骨破坏,CT数据分析观察组及对照组肿瘤体积大小组间差异无显著性（P〉0.05）,环磷酰胺组肿瘤体积明显小于前两组,组间有显著性（P〈0.05）,而观察组骨量大于对照组,低于环磷酰胺组,3组组间差异有显著性（P〈0.05）,病理学显示溶骨性病变为主的混合性骨质破坏,观察组及对照组骨结构破坏严重,肿瘤细胞填充明显,免疫组化显示腺瘤,两组差异相似,观察组ALP浓度大于对照组及环磷酰胺组,观察组与对照组及环磷酰胺组相比,组间差异有显著性（P〈0.05）。结论间歇性小剂量注射甲状旁腺激PTH（1-34）不促进小鼠肺癌骨转移瘤的生长,但增加骨转移瘤灶周围的骨量。

Objective To investigate the effect of parathyroid hormone （1-34） （PTH） on tumor growth in a mouse model of lung cancer with bone metastasis. Methods Mouse models of proximal tibial bone metastasis of lung Cancer were established in 30 female BALB/c mice. The mouse models were randomly divided into 3 groups and received injections with 40 mg/kg PTH （1-34）, equal amount of solvent （blank control）, or cyclophosphamide （positive control）. Body weight of the mice was measured every 2 days and the right hind limb tumor growth was observed. The mice were sacrificed after 28 days for X-ray and CT examinations to observe the tumor shape, size, tibial bone density, and tumor volume. HE staining and immunohistochemistry were performed to observe the tumor morphology and pathological type, and serum concentration of serum alkaline phosphatase （ALP） was detected. Results The body weight change curves did not show significant difference between PTH （1-34） group and the blank control group （P〉0.05）. In both PTH （1-34） group and the blank control group, X-ray and micro-CT revealed significant bone defects, and in cyclophosphamide group the bone cortex was basically intact with only mild bone destruction. The tumor volume was similar between PTH （1-34） group and the blank control group （P〉0.05）, but significantly smaller in cydophosphamide group （P〈0.05）. The bone density in PTH （1-34） group was significantly greater than that in the blank control group, but lower than that in cyclophosphamide group （P〈0.05）. Pathological examination revealed mainly osteolytic lesions mixed with bone destruction, which was severer in PTH （1-34） group and blank control group with obvious tumor cell filling of the defects; immunohistochemistry identified the tumors as adenomas. ALP activity was higher in PTH （1-34） group than in the other two group and differed significantly between the 3 groups （P〈0.05）. Conclusion Intermittent small-dose injections of parathyroid hormone PTH （1-34） does not promote bone metastatic tumor growth in mice and increases the bone quantity around the metastatic lesions.