Lewis肺癌细胞趋化因子受体CXCR4表达的研究

Expression of chemokine receptor CXCR4 in Lewis lung carcinoma cells

目的:观察趋化因子受体CXCR4在Lewis肺癌细胞和肿瘤组织中的表达,为探讨CXCR4与肿瘤转移的关系提供研究基础。方法:体外培养Lewis肺癌细胞,并建立Lewis肺癌细胞皮下种植瘤模型与自发性转移模型,采用RT-PCR和蛋白质印迹法分析培养细胞和肿瘤组织中CXCR4 mRNA及蛋白质表达水平;应用免疫组化方法分析Lewis肺癌原发瘤和转移瘤中CXCR4表达,并通过迁移实验观察CXCR4特异性配体SDF-1α对Lewis肺癌细胞的趋化作用。结果:培养Lewis肺癌细胞及肿瘤组织中均功能性地表达趋化因子受体CXCR4,且其表达水平与细胞所处氧环境有关;低氧能够促使Lewis肺癌细胞CXCR4蛋白表达增高,与对照组相比差异有统计学意义,t=4.051,P=0.009。12h细胞趋化运动实验显示,CXCR4特异性配体SDF-1α可剂量依赖性诱导Lewis肺癌细胞的趋化运动,在低氧条件下,同对照组相比SDF-1α质量浓度为25ng/mL时开始促进细胞迁移,t=3.053,P=0.031;SDF-1α质量浓度为50ng/mL时可明显提高细胞迁移率,t=4.521,P=0.004。结论:Lewis肺癌细胞功能性表达趋化因子受体CX-CR4,可能与肿瘤细胞迁移和转移有关。

OBJECTIVE： To explore the expression of chemokine receptor CXCR4 in Lewis lung carcinoma and build the basis for investigating the relationship between the receptor and tumor metastasis. METHODS： The mRNA level and protein expression of chemokine receptor CXCR4 were detected by RT-PCR and Western blot. Immunohistochemistry assay was performed to evaluate the expression of CXCR4 in primary and metastatic tumor of Lewis lung carcinoma. The cell chemotactic mobility responding to SDF-1α, the specific ligand of CXCR4, was analyzed by migration assay. RESULTS： Expression of CXCR4 in Lewis lung carcinoma was proved in vivo and in vitro, and was related to oxygen concentration of cell niche. In hypoxic condition the expression of CXCR4 mRNA and protein in Lewis lung carcinoma was upregulated significantly, t=4. 051,P=0. 009. Moreover, migratory response of Lewis lung carcinoma cells could be induced by SDF-1α, the specific ligand of CXCR4. After treated with 25 ng/mL SDF1-α for 12 hours, the rate of migration was increased, t=3.053, P=0.031. And with 50 ng/mL SDF1-α, the rate of migration was increased significantly, t = 4. 521, P= 0. 004. CONCLUSION： These results suggeste that CXCR4 is functionally expressed in Lewis lung carcinoma cells and possibly involved in tumor cell migration and metastasis.