中文摘要：

目的观察RanBP9（Ran—bindingprotein9）在骨肉瘤细胞的表达情况和对骨肉瘤细胞增殖、凋亡及转移的影响，探讨RanBP9在骨肉瘤细胞生物学功能中发挥的作用。方法Real—timePCR、免疫荧光细胞染色和Westernblot检测不同骨肉瘤细胞系中RanBP9的mRNA和蛋白表达水平；利用慢病毒建立稳定低表达RanBP9的SaOS2细胞模型并检测低表达RanBP9对骨肉瘤细胞SaOS2细胞增殖、克隆形成、凋亡及迁移、侵袭等细胞生物学功能的影响。结果RanBP9在MG63、SaOS2、U20S3个骨肉瘤细胞系中呈阳性表达，并且在低级别骨肉瘤细胞系MG63中的表达高于高级别细胞系SaOS2和U20S（P〈0．05）；稳定低表达RanBP9的SaOS2细胞（siRanBP9）的增殖、克隆形成、迁移、侵袭能力均较对照细胞siCON—SaOS2（siCON）增强，差异有统计学意义（P〈0．05），而凋亡率下降，有显著差异（P〈0．05）。结论低表达RanBP9的骨肉瘤细胞的增殖和转移能力增强，凋亡率下降，RanBP9可能作为一个抑癌基因参与了骨肉瘤的发生与演进。

英文摘要：

Objective To explore the effect of Ran-binding protein 9 （RanBP9） expression on the proliferation, apoptosis and metastasis in human osteosarcoma cells, so as to discuss its biological functions in osteosarcoma cells. Methods Real-time PCR, immunofluorescence assay and Western blotting were used to examine RanBP9 mRNA and protein expression levels in osteosarcoma cell lines. Also we performed a series of biological tests using osteosarcoma SaOS2 cell line to study the effects of RanBP9 down-regulation on the prolif- eration, clone formation, apoptosis and metastasis in SaOS2 cells. Results We found that RanBP9 was highly expressed in human osteosarcoma cell lines and RanBP9 expression was significantly higher in MG63 cell line derived from low-grade osteosarcoma than in U2OS or SaOS2 cell lines derived from high-grade osteosarcoma （P 〈 0.05）. Immunofluorescence assay and Western blotting also showed the same results. Low expression of RanBP9 in SaOS2 cell line not only markedly increased cell vitality, growth and colony formation, but also stimulated migration and invasion （P 〈 0. 05 ） as compared with control cells （ siCON-SaOS2 ）. Consistently, down-regulated RanBP9 was associated with reduced basic apoptosis assayed by annexin APC-PI （P 〈 0. 05）. Conclusion Low expression of RanBP9 reduces apoptosis and increases osteosarcoma cell proliferation as well as metastasis, suggesting that RanBP9 may be a tumor-suppressor involving in the occurence and development of osteosarcoma.