CXCL12/CXCR4通路在人肺腺癌细胞诱导破骨 细胞前体细胞向破骨细胞分化中的作用.

Objective To explore the role of the chemokine 12（CXCL12)/chemokine receptor 4（CXCR4）pathway in human lung adenocarcinoma cells-induced differentiation of osteoclast precursor cells into osteoclasts and the possible molecular mechanism. Methods The Abelson leukemia virus-transformed murine monocyte/macrophage-like RAW 264. 7 cells acted as osteoclast precursor cells，and were randomly divided into the treatment group and control group. Both groups were inoculated with RAW 264. 7 cells in the lower Transwell chamber and A549 cells in the upper Transwell chamber. The treatment group was separately treated with a culture medium containing the competitive CXCR4 antagonist AMD3100 at 12. 5，25. 0，50. 0，and 100. 0 μg/mL in the Transwell chamber，and the control group was only given a culture medium. After 7 days of culture，cells in both groups received tartrate-resistant alkaline phosphatase（TRAP）staining to count the number of RAW 264. 7 cells differentiating into osteoclasts. Quantitative PCR was used to measure the mRNA levels of the following osteoclast marker genes in the lower Transwell chamber：cathepsin K（CTSK)，calcitonin receptor（CTR)，TRAP，and receptor activator of nuclear factor-κB（RANK). ELISA was used to determine the levels of CXCL12，interleukin 6（IL-6)，and tumor necrosis factor-α（TNF-α）in the supernatant in the chamber. Results In the treatment group，the numbers of RAW 264. 7 cells differentiating into osteoclasts were 81±3，49±3，34±3，and 11±2 after 12. 5，25. 0，50. 0，and 100. 0 μg/mL AMD3100 treatment，all of which were significantly lower than that in the control group（99±5)，and the number of RAW 264. 7 cells differentiating into osteoclasts decreased significantly with the increased concentrations of AMD3100（all P<0. 05). Compared with the control group，the treatment group showed significantly reduced mRNA expression of the osteoclast marker genes CTSK，CTR，TRAP，and RANK and significantly decreased levels of CXCL12，IL-6，and TNF- α in the cell supernatant after treatment with various concentrations of AMD3100（all P<0. 05). As the concentration of AMD3100 increased，the expression of the osteoclast marker genes and the levels of CXCL12，IL-6，and TNF-α gradually decreased（all P<0. 05). Conclusion Inhibiting the CXCL12/CXCR4 pathway can reduce human lung adenocarcinoma cells-induced differentiation of osteoclast precursor cells into osteoclasts，which may be achieved by reducing the expression of IL-6 and TNF-α. [ABSTRACT FROM AUTHOR]