乙肝病毒X蛋白结合蛋白在体外调节IGF-1表达参与乳腺癌细胞转移

HBXIP Upregulates IGF-1 Involved in Migration of Breast Cancer Cells in vitros

目的:探讨HBXIP通过调节IGF-1促进乳腺癌细胞迁移的作用及机制,为进一步阐明HBXIP促进乳腺癌细胞迁移的分子机制奠定基础。方法:采用RT-PCR和Western blot等分子生物学方法,检测HBXIP与IGF-1在不同迁移能力的乳腺癌细胞中mRNA和蛋白水平的表达情况,并检测过表达和干扰HBXIP后IGF-1的mRNA和蛋白表达水平。结果:HBXIP和IGF-1在mRNA和蛋白水平的表达,于T47D、MCF-7及MDAMB-231 3种不同迁移能力的乳腺癌细胞间均有显著性差异(P<0.05),且均与乳腺癌细胞的迁移能力成正比。在MCF-7细胞中过表达HBXIP后,pCMV-HBXIP(1μg)和pCMV-HBXIP(2μg)2组中IGF-1的mRNA表达水平,与pCMV组相比均显著增高(P<0.05),而蛋白水平上,pCMV-HBXIP(120ng)、pCMV-HBXIP(250ng)和pCMV-HBXIP(500ng)3组中IGF-1的表达,与pCMV组相比亦显著增高(P<0.05);相反,在MDA-MB-231细胞中干扰HBXIP后,HBXIP-siRNA(50nM)和HBXIP-siRNA(100nM)2组中IGF-1在mRNA和蛋白水平的表达,与NC siRNA组相比均显著降低(P<0.05)。结论:HBXIP在体外可通过上调IGF-1的表达促进乳腺癌细胞的迁移,推测可能与HBXIP辅激活子活性有关。

Objective： To explore the role and mechanism of HBXIP in promoting breast cancer cell migration by regulating IGF-1, and to lay a foundation for further elucidation of the molecular mechanism of HBXIP promoting breast cancer cells migration. Methods： RT-PCR and western blot were used to detect the mRNA and protein expression levels of HBXIP and IGF-1 in breast cancer cells with different cellular migration ability and to examine the mRNA and protein expression levels of IGF-1 after the overexpression and interference with HBXIP. Results： The mRNA and protein expression levels of HBXIP and IGF-1 were significantly different among T47D, MCF-7 and MDA MB-231, breast cancer cells with different migration abilities（P〈0. 05） ,and the expression levels were directly proportional to the migration ability of breast cancer cells. Furthermore, After overexpression of HBXIP in MCF7, the mRNA expression level of IGF-1 in pCMV-HBXIP（1 μg） and pCMV-HBXIP（2 μg） were significantly higher than that of pCMV （P〈0. 05） ,and the protein expression level of IGF-1 in pCMV HBXIP（120 ng） ,pCMV HBXIP（250 ng）and pCMV HBXIP（500 ng） were also significantly higher than that of pCMV （P〈0.05）. In contrast,after interference with HBXIP in MDA-MB-231,the mRNA and protein expression levels of IGF-1 in HBXIP siRNA （50 nM） and HBXIP siRNA（100 nM） were significantly lower than that of NC siRNA（P〈0.05）. Conclusion： HBXIP can promote the migration of breast cancer cells by up-regulating the expression of IGF-1 in vitro, which may be related to its role as a vital transcription factor coactivator.