IEX-1相互作用蛋白的筛选与鉴定

Characterization of Interaction Protein for Osteosarcoma Related Protein IEX-1

骨肉瘤即原发于骨的恶性肿瘤,易发生早期肺转移且预后差,恶性程度高.本研究小组前期研究发现,IEX-1在骨肉瘤中具有重要作用.为了阐明其作用机制,本研究运用酵母双杂交技术筛选其相互作用蛋白,共鉴定出12个IEX-1相互作用蛋白,包括生物氧化相关酶类、分子伴侣、信号转导相关蛋白等.并首次证实clusterin(CLU,又名载脂蛋白J)与IEX-1存在相互作用,两者在细胞中具有很好的共定位.采用RNAi干扰减低骨肉瘤细胞中内源性CLU表达水平,显著抑制了细胞增殖与细胞侵袭能力.为阐明IEX-1在骨肉瘤发生发展中的作用机制提供了重要的线索,为骨肉瘤的早期诊治及预后监测提供了新的靶点.

Primary osteosarcoma is the most frequent malignant tumor in bone with early pulmonary metastasis and poor prognosis. Our previous study found that overexpression of IEX-1 in osteosarcoma plays an important role in initiation and development of osteosarcoma. In order to elucidate the mechanism of IEX-1 in osteosarcoma, we have screened its interaction proteins by using yeast two hybrid system.Twelve IEX-1 interacting proteins were identified, including biological oxidation related enzymes, chaperones, signal transduction related protein, etc. The interaction between IEX-1 and CLU was confirmed in vitro through co-immunoprecipiation in combination with Western blotting and immunostaining. Knock down of endogenous CLU expression in osteosarcoma ceils significantly inhibit cell proliferation and cell invasion ability in vitro. This preliminary study on the molecular mechanisms that how IEX-1 promote the occurrence and development of osteosarcoma provides novel clues for early-stage diagnosis and target gene therapy of this malignant bone tumor.