Regulation of MCP-1 in Osteoblasts by PTHrP in Breast Cancer Cells / 天津医药

ABSTRACT

Objective:To identify the regulation of monoeyte chemoattractant protein-1(MCP-1)in osteoblasts by parathyroid hormone related protein(PTHrP) in breast cancer cells.Methods:Osteoblast-like UMR106 cells were treated with 10~(-8)mol/L PTHrP (1-34) for different times and the expression of MCP-1 was studied by semiquantitative RT-PCR.Recombinant shRNA plsmid PTH1R/pRNAT was constructed and transfected into UMR106 cells.Stable PTH1R/UMR106 cells were established,in which PTH1R expression was knocked-down.The conditioned medium(CM) of breast cancer MDA-MB231 was added to UMR 106 and PTH1R/UMR106 cultures respectively.Thereafter,mRNA of MCP-1 was examined by semiquantitative RT-PCR.Results:PTHrP induced expression of MCP-1 in UMR106 cells and the induction began at 3 h and reached the maximum at 6 h.Treatment of UMR106 cells with CM of MDA-MB231 also significantly induced mRNA of MCP-1 at 6 h(1.238 1±o.115 5 and 0.598 4±0.036 4,P＜0.05).This effect was partly blocked by the knockdown of PTH1R in UMR106 cells(0.867 2±0.045 7,P＜0.05).Conclusion:The osteoblastic MCP-1 is up-regulated in breast cancer through expression of PTHrP.