黏附分子αvβ3和αvβ5介导肿瘤细胞与肿瘤内皮细胞的黏附

目的 体外分析黏附分子αvβ3和αvβ5及其配体Del-1、L1在肿瘤细胞-内皮细胞黏附中的作用.方法 应用逆转录聚合酶链反应(RT-PCR)和流式细胞分析比较正常肝窦内皮细胞(LSEC)和肝癌的血管内皮细胞T3A上细胞间黏附分子1(ICAM-1)、αvβ3和αvβ5的表达以及缺氧对其表达的调控.分别用RT-PCR和Western blot方法分析6种肿瘤细胞Del-1和L1的表达及缺氧对其表达的调控.使用连续光谱荧光测定仪定量肿瘤细胞在LSEC和T3A上的黏附,并分析抗不同黏附分子的抗体和siRNA对肿瘤细胞一内皮细胞黏附的阻断作用.结果 T3A细胞αvβ3和αvβ5的基础表达高于LSEC,而ICAM-1的基础表达低于LSEC.缺氧上调两种内皮细胞αvβ3和αvβ5的表达,而ICAM-1表达仅在LSEC中升高.在不同肿瘤细胞中,Del-1和L1的基础表达存在明显差异,并且在缺氧条件下受到明显不同的调节.Del-1和L1高表达的肿瘤细胞在T3A细胞的黏附明显高于LSEC,并且在缺氧条件下黏附明显增加,这种黏附可以被抗αvβ3、αvβ5的抗体或沉默β3和β5的小干扰RNA(siRNA)阻断.结论 细胞黏附分子αvβ3、αvβ5及其配体在肿瘤细胞-肿瘤内皮细胞的黏附过程中起重要介导作用.

Tumor cell-tumor endothelial cell adhesion mediated by αv β3 and αβ5 molecules

Objective To investigate the role of adhesion molecules αvβ3 and αvβ5 and their ligands Del-1 and L1 in the tumor-endothelial cell adhesion in vitro.Methods The expression of αvβ3,αvβ5 and ICAM-1 in liver sinusoidal endothelial cells (LSEC) and liver cancer endothelial cells(T3A)cultured under normoxia or hypoxia were analyzed by RT-PCR and fluorescent activated cell sorter(FACS).The expression of Del-1 and L1 in six tumor cell lines under normoxia or hypoxia were analyzed by RT-PCR and Western blot,respectively.The adhesion of dye-labeled tumor cells and endothelial LSEC and T3A cells was measured by a fluorescence plate reader after their culture.Results The expression of αvβ3 and αvβ5 were higher in T3A cells than that in LSEC cells,and were upregulated under hypoxia,while the expression of ICAM-1 was lower in T3A cells than that in LSEC cells,and was upregulated under hypoxia only in LSEC.The expression of Del-1 and L1 molecules were obviously different in various tumor cell lines and were differentially regulated under hypoxia.The adhesion of tumor cells with Del-1 or L1 expression was higher in T3A cells than that in LSEC cells,and was significantly increased under hypoxia condition.Furthermore,the adhesion of tumor cells to T3A could be inhibited by antibodies against αvβ3 and αvβ5,or SiRNAs for β3 and β5.Conclusion αvβ3 and αvβ5 and their ligands Del-1 and L1 may play an important role in tumor cell migration.