摘要目的 探讨CCCTC结合因子(CCCTC-binding factor,CTCF)在细胞核内的定位以及该基因表达水平的细胞类型特异性.方法 通过蛋白质印迹技术对乳腺癌细胞MCF-7的不同细胞组分中CTCF蛋白的含量进行了分析；应用蛋白质免疫荧光技术,通过共聚焦显微镜分析系统对CTCF在MCF-7单细胞中的定位进行了分析；然后通过蛋白质印迹技术和RT- qPCR技术分别对CTCF在正常外周血白细胞、MCF-7以及淋巴瘤细胞Jurkat和Ramos等不同类型细胞中的表达水平进行了分析.结果 蛋白质印迹和蛋白质免疫荧光技术的分析结果表明CTCF主要分布在细胞核内.蛋白质印迹和RT-qPCR技术的分析结果表明CTCF在这些不同细胞类型中的表达水平各不相同,与正常细胞相比较,CTCF在肿瘤细胞中的表达水平明显增高；在不同类型的肿瘤细胞中的表达水平也存在着很大的差异性.结论 CTCF是一种细胞核内特异定位的蛋白因子,CTCF的表达水平具有细胞类型特异性.

abstractsObjective To investigate the distribution of CCCTC-binding factor (CTCF) in cell nucleolus and the cell-type specific expression levels of the gene in different cell lines.Methods Using the Western-blot technique,the distribution of CTCF in the MCF-7 cells was analyzed.And the location of CTCF in the single MCF-7 cell space was analyzed using the confocal laser scanning microscope with the immunofluorescence technique.With the quantitative RT-PCR and Western-blot assays,the CTCF expression levels.were determined in different cell lines of the normal peripheral white blood cells,MCF-7,and the lymphoma cells of Jurkat and Ramos.Results The results of Western-blot and immunofluorescence assays showed that CTCF was distributed in cell nucleus.The results of the quantitative RT-PCR and Western-blot assays showed that CTCF expression level was variable in different cancer cell lines.Compared with those of natural cells,the expression level was increased in cancer cell lines.Conclusion The results suggested that CTCF was a type of nucleus-located protein factors.Its expression level was cell type-specific.