基质细胞衍生因子在多发性骨髓瘤细胞迁移和黏附中生物学作用的研究

Study of biological behavior of stromal cell-derived factor-1 on multiple myeloma cell migration and adhesion

目的研究基质细胞衍生因子(SDF-1)在多发性骨髓瘤(MM)细胞迁移、黏附中的生物学作用以及相关信号转导。方法采用流式细胞术检测 MM 细胞系 RPMI8226、XG-1、XG-7细胞黏附分子表达;免疫荧光技术检测 SDF-1对细胞形态以及膜表面黏附分子分布的影响;通过微孔隔离实验检测 SDF-1对 MM 细胞的趋化作用及磷脂酰肌醇3激酶(PI3K)在趋化过程中的作用;免疫印迹技术检测 MM 细胞 SDF-1对 PI3K的活化。结果 3种 MM 细胞系不同程度表达多种黏附分子,RPMI8226、XG-7细胞均高表达黏附分子 CD29(>70%)、XG-1、XG-7细胞均高表达 CD44(>80%),XG-7细胞高表达 CD49d(>90%);3种细胞系 CD49e 表达水平均较低(<30%);这些黏附分子表达水平不能被SDF-1α明显上调。SDF-1α可触发 MM 细胞的极化形态建立以及诱导 CD29、CD49e 在细胞膜的重分布。SDF-1α能促进 MM 细胞对内皮细胞的黏附,并能够诱导 MM 细胞的迁移,此作用被 G 蛋白抑制剂 PTX 及 PI3K 抑制剂 wortmannin 明显抑制。结论 SDF-1α促进 MM 细胞对内皮细胞的黏附;并触发MM 细胞的极化形态建立及诱导黏附分子的重分布,从而通过 PI3K 信号途径诱导 MM 细胞的迁移。

Objective To investigate the biological behavior of stromal cell-derived factor-1 （SDF-1） on multiple myeloma（MM） cell migration and adhesion and it related signaling pathways. Methods Expression of adhesion molecules on MM cells of RPMI8226,XG-1 and XG-7 cells was analysed by flow cytometry, the influence of SDF-1 on CD29 and CD49e distribution by immunofluoreseence, the effect of SDF-1 on ehemotaxis of MM cells by transwell assay. Activation of phosphoinositide-3 kinase（P13K） in MM cells treated with SDF-1 and by immunoblotting. Results 3 strains of MM cell line expressed many adhesion molecule. RPMI8226 ,XG-7 cells were all high level of expression of CD29 （ 〉70% ）. XG-1, XG-7 cells were all high level of expression of CD44 （ 〉 80% ）, and XG-7 cells was of CD49d （ 〉 90% ）. In all of 3 strains, the levels of expression of CIM9e were low （ 〈 30% ）. SDF-1 could not upregulate their expression, but could trigger the establishment of polarized morphology of MM cells and the redistribution of CD29 and CD49e. SDF-1 promoted MM cells adhesion to endothelial cells, stimulated phosphorylation of P85 subunit of PI3K in MM cells and induced MM cells migration,which were inhibited by G protein inhibitor PTX and PI3K inhibitor wortmannin. Conclusion SDF-1 can promote MM cell adhesion to endothelial cells, trigger establishment of a polarized morphology of MM cells and redistribution of adhesion molecules and induce MM cells migration via PI3K signaling pathway.