目的: 以乳腺癌细胞与成骨细胞共培养模拟乳腺癌骨转移微环境，观察在此微环境中降钙素基因相关肽( calcitonin generelated peptide，CGRP)对成骨细胞护骨素 （osteoprotegerin，OPG）及细胞核因子κB受体活化因子配体（receptor activator of nuclear factorkappa B ligand, RANKL；又称破骨细胞分化因子）表达的影响。方法：将转移性乳腺癌细胞MDAMB231或MDAMB435与成骨细胞MG63共培养，建立模拟乳腺癌骨转移微环境。行CGRP(1×108 mol/L)干预，应用RTPCR和Western Blotting技术检测干预后OPG和RANKL在mRNA和蛋白水平表达的变化。结果：MG63与MDAMB231或MDAMB435共培养环境中，RANKL mRNA及蛋白水平升高，而OPG mRNA和蛋白水平表达下降；CGRP处理后，共培养环境中RANKL mRNA及蛋白水平降低，OPG mRNA和蛋白水平升高 (均P<0.05)。结论：乳腺癌细胞能调节成骨细胞OPG/RANKL轴的表达，进而可能促进破骨细胞的活性,造成溶骨性破坏；CGRP 干预可逆转此调节作用，在乳腺癌骨转移的治疗中有潜在应用价值。

Objective:To observe the effect of calcitonin generelated peptide (CGRP) on the expression of osteoprotegerin (OPG) and receptor activator of nuclear factorkappaB ligand (RANKL) in osteoblast cells through an in vitro breast cancer cell and osteoblast cell coculture system.Methods:The metastatic breast cancer MDAMB231 or MDAMB435 cells were cocultured with osteoblast MG63 cells to establish an in vitro microenvironment of bone metastasis of breast cancer. After treated with CGRP(1×108 mol/L), OPG and RANKL mRNA and protein expressions in osteoblast MG63 cells were examined by RTPCR and Western blotting. Results: Expression of RANKL in osteoblast MG63 cells was upregulated at both mRNA and protein levels when osteoblast MG63 cells were cocultured with breast cancer MDAMB231 or MDAMB435 cells, while those of OPG in osteoblast MG63 cells were both downregulated (P<0.05). After treatment with CGRP, expressions of RANKL in osteoblast MG63 cells were downregulated at both mRNA and protein levels, and the expressions of OPG mRNA and protein were both upregulated (P<0.05). Conclusion: Breast cancer MDAMB231 and MDAMB435 cells can promote osteolysis of osteoclast cells via regulating the expression of OPG/RANKL axis in osteoblast cells. CGRP can reverse the osteolysis of osteoblast cells induced by breast cancer cells and may serve as a potential therapeutic agent for treatment of bone metastasis of breast cancer.

上海市市级医院慢性病综合防治项目(No.SHDC12007304)