中文摘要：

目的：探讨基质细胞衍生因子1（SDF-1）及其受体CXC趋化因子受体4（CXCR4）在肾癌细胞转移中的作用机制,观察不同区段CXCR4在肾癌细胞内的定位。方法：应用核定位分析软件结合实验,构建不同长度的CXCR4与绿色荧光蛋白pEGFP-N1重组表达载体,转染肾透明细胞癌A498细胞株后用共聚焦显微镜观察重组表达载体在细胞内的定位。结果：生物信息学分析软件PSORTⅡPrediction发现第146～149位氨基酸残基RPRK可能是CXCR4的核定位序列,我们构建的重组质粒EGFP-CXCR4（1～510bp）、EGFP-CXCR4（1～765bp）、野生型全长EGFP-CXCR4分别加SDF-1刺激因子后其表达产物主要呈细胞核分布,而加入SDF-1刺激因子后重组质粒EGFP-CXCR4（1～267bp）的表达产物呈细胞质分布,未经SDF-1刺激野生型全长EGFP-CXCR4其表达产物呈细胞质分布,与生物信息学分析软件预测结果基本吻合。结论：CXCR4的第90～170位氨基酸残基含有核定位序列,为进一步精确定位CXCR4在肾癌细胞内的核定位序列以及寻找抑制肾癌转移的可能靶标奠定了实验和理论基础。

英文摘要：

Objective：To investigate the role of SDF-1/CXCR4 in metastasis of renal cell carcinoma and to observe the intracellular location of different CXCR4 segments in renal carcinoma cells.Methods：The potential nuclear localization sequences of different CXCR4 were discovered by nuclear localization software and experiments.Full length and truncated forms of CXCR4 were fused with green fluorescent protein pEGFP-N1 and their influence on subcellular localization was examined by confocal microscopy after transfecting them into renal carcinoma cell line A498. Results.. Analysis with PSORT Ⅱ Prediction revealed that the nuclear localization sequence region of CXCR4 was located between amino acids 146 and 149 （RPRK）. Expression products of the recombinant plasmids with SDF-1 stimulation,including EGFP-CXCR4（ 1-510 bp）, EGFP-CXCR4（ 1-765 bp） and wild-type EGFP-CXCR4, were mainly located in the cell nuclei. However, expression product of EGFP-CXCR4（ 1-267 bp） with SDF-1 stimulation was mainly located in the renal cell cytoplasm.. Expression product of wild-type EGFP-CXCR4 full length plasmid without SDF-1 stimulation was mainly located in the cell cytoplasm; these results accorded with the results of bioinformatics analysis. Conclusion： Nuclear localization sequence of CXCR4 is located in the amino acids 90 to 170 ,which provides a theoretical basis for further clarifying the nuclear localization sequences of CXCR4 in renal cell carcinoma ceils and for finding new potential target for inhibiting the metastasis of renal cell carcinoma.