乳腺癌细胞通过PTHrP调节成骨细胞MCP-1基因表达

Regulation of MCP-1 in Osteoblasts by PTHrP in Breast Cancer Cells

目的:探讨乳腺癌细胞分泌的甲状旁腺激素相关蛋白(PTHrP)对成骨细胞单核细胞趋化蛋白-1(MCP-1)基因表达的调节作用。方法:首先将10-8mol/L剂量的PTHrP(1-34)作用于成骨细胞UMR106,同时设立对照组,半定量RT-PCR法分析对不同时间成骨细胞的MCP-1mRNA表达;之后构建PTHrP受体(PTH1R)的shRNA重组质粒PTH1R/pRNAT,将其转染至成骨细胞UMR106,建立稳定表达的细胞系PTH1R/UMR106;将乳腺癌细胞MDA-MB231条件培养基(CM)分别作用于UMR106和PTH1R/UMR106,半定量RT-PCR法测定MCP-1的mRNA表达。结果:PTHrP可以促进成骨细胞MCP-1的表达,起始于3h,6h到达高峰(P<0.05)。乳腺癌细胞CM作用UMR106成骨细胞6h后,MCP-1表达水平也较未处理组明显升高(分别为1.2381±0.1155和0.5984±0.0364,P<0.05),而采用RNA干扰技术敲减PTH1R表达后,乳腺癌细胞CM对成骨细胞MCP-1表达的作用明显减弱(降低至0.8672±0.0457,P<0.05)。结论:乳腺癌细胞可通过PTHrP调节成骨细胞MCP-1。

Objective：To identify the regulation of monocyte 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±0.115 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.