内皮细胞肌球蛋白轻链激酶调控纤维肉瘤细胞血管外游走的实验研究

Functional regulation of endothelial Myosin light chain kinase in extravascular migration of fibrosarcoma cells

目的:阐明内皮细胞肌球蛋白轻链激酶在纤维肉瘤细胞血管外游走过程中的调控机制。方法:利用血管外游走的体外模型,观察纤维肉瘤细胞(HT1080)的血管外游走状况,并测定游走过程中血管内皮单细胞层的电阻变化,进行细胞内磷酸化实验,利用放射自显影技术,评价纤维肉瘤细胞游走过程中内皮细胞肌球蛋白轻链的磷酸化水平。结果:纤维肉瘤细胞可以穿过血管内皮细胞游走至血管外,并且游走过程中跨血管内皮细胞层的电阻下降,内皮细胞肌球蛋白轻链的磷酸化水平升高。内皮细胞肌球蛋白轻链激酶抑制剂(ML-7)能够抑制上述变化,并具有浓度依赖性。结论:内皮细胞肌球蛋白轻链激酶可通过调控肌球蛋白轻链的磷酸化水平,引起骨架重组、细胞收缩,从而导致纤维肉瘤细胞穿过内皮细胞间缝隙向血管外游走。

Objective： To evaluate the functional regulation of endothelial Myosin light chain kinase （MLCK） in extravascular migration of fibrosarcoma HT1080 cells. Methods： An in vitro model of fibrosarcoma cell transmigration across a monolayer of HUVEC cultured on collagen gel was applied to observe extravascular migration of HT1080 cells,and were the electrical resistance of HUVEC monolayer and endothelial MLC phosphorylation in extravascular migration of HT1080 cells. Results： HT1080 cells migrated through endothelial cells into collagen gel, the electrical resistance of a HUVEC monolayer was reduced and endothelial MLC phosphorylation was enhanced in extravascular migration of fibrosarcoma cells. Endothelial MLCK inhibitor （ML-7） blocked extravascular migration of HT1080 cells and inhibited reduction of electrical resistance of a HUVEC monolayer and enhancement of endothelial MLC phosphorylation in extravascular migration of HT1080 cells in a dose-dependent manner. Conclusion. Endothelial MLCK regulates fibrosarcoma cell transendothelial migration through MLC phosphorylation, leading to cytoskeletal reorganization and endothelial cell constriction, then fibrosarcoma cells migrate into extravascular tissue through the gaps between endothelial cells.