中文摘要：

探讨在体外模拟的乳腺癌骨转移微环境中，采用RNAi技术下调骨形态发生蛋白9（bonemorphogeneticprotein9，BMP9）基因对人乳腺癌SK-BR-3细胞增殖、迁移的影响及可能机制。用Transwell小室将空白组SK—BR-3细胞、感染腺病毒AdRFP的对照组SK-BR-3／RFP细胞、感染腺病毒AdsiBMP9的实验组SK—BR-3／siBMP9细胞分别与人骨髓基质HS-5细胞间接共培养后，MTT增殖实验、划痕愈合实验、Transwell迁移实验分别检测下调BMP9对SK-BR-3细胞增殖、迁移的影响：RT-PCR和Westernblot法检测相关因子的变化。结果显示，在共培养体系中，SK．BR-3／siBMP9组的BMP9显著低于对照组（P〈0．05）；下调BMP9可有效促进SK—BR-3／siBMP9细胞增殖（P〈0．05），SK—BR-3／siBMP9细胞的划痕愈合率、穿膜细胞数也明显升高（P〈0．05）；SK—BR-3／siBMP9组血管内皮细胞生长因子（VEGF）、结缔组织生长因子（CTGF）mRNA和蛋白表达均显著上调（P〈0．05），且Westernblot结果显,-Tz,p—AKT显著_LiN（P〈0．05）。综上，在骨转移微环境中，干扰BMP9表达可促进人乳腺癌SK-BR-3细胞增殖及迁移，其作用机制可能与上调VEGF、CTGF表达有关，且这个过程可能涉及P13K／AKT通路的激活。

英文摘要：

To investigate the effects of siRNA-mediated down-regulation of human bone morphogenetic protein 9 （BMP9） on proliferation and migration of human breast cancer SK-BR-3 cells and its possible mechanism in simulated bone microenvironment in vitro, SK-BR-3 cells as blank group, SK-BR-3/RFP cells infected with ade- novirus RFP as control group, and SK-BR-3/siBMP9 cells infected with adenovirus siBMP9 as experimental group were indirectly co-cultured with human bone marrow stromal cells HS-5 with Transwell chamber. Effects of down- regulating BMP9 on SK-BR-3 cell proliferation and migration were investigated by MTT, wound-healing test and transwell migration test; The expression of related factors were screened by RT-PCR and Western blot. The result showed that in the co-culture system, the expression of BMP9 was decreased in SK-BR-3/siBMP9 group （P〈0.05）; Down-regulating BMP9 could promote the proliferation of SK-BR-3/siBMP9 cells （P〈0.05）, and the wound-heal- ing rate and the number of migratory cells were remarkably increased （P〈0.05）; Compared with the control group, the expressions of VEGF and CTGF were significantly up-regulated at mRNA and protein levels in SK-BR-3/ siBMP9 group （P〈0.05）, and Western blot showed p-Akt was higher than the control group （P〈0.05）. All together, down-regulating BMP9 can promote the proliferation and migration of breast cancer cells SK-BR-3 in microenvi- ronment of bone metastasis, which may be related to up-regulating the expressions of VEGF and CTGF, and PI3K/ Akt pathway may be involved in this process.