细胞凋亡在人乳腺癌细胞拟态血管形成中的作用

The involvement of apoptosis in vasculogenic mimicry formation of human breast cancer cells

目的:研究细胞凋亡对人乳腺癌细胞(MDA-MB-231)体外形成拟态血管的影响。方法:建立体外人工基底膜三维细胞培养模型,观察乳腺癌细胞能否形成血管样结构。用Annexin-FITC细胞凋亡检测试剂盒测定血管样结构形成过程中细胞凋亡情况;加入caspase抑制剂Z-VAD-FMK和caspase-3抑制剂Ac-DEVD-CHO后观察其对血管样结构的影响。结果:三维培养24 h时,乳腺癌细胞伸出细长突起,彼此相互连接,形成腔隙样结构;经PAS染色,可见环状PAS阳性图案,表明乳腺癌细胞在体外可以形成拟态血管。细胞三维培养后凋亡细胞数开始增多,8 h达到高峰,此后凋亡细胞数下降,24 h时凋亡细胞数与对照组相比无明显差异。Z-VAD-FMK和Ac-DEVD-CHO均能明显抑制三维培养状态下细胞拟态血管的形成。结论:在体外三维培养条件下,人乳腺癌细胞可形成拟态血管,而细胞凋亡过程是恶性肿瘤细胞拟态血管形成的关键环节之一。

Objective： To investigate the effect of cell apoptosis on the vasculogenic mimicry in human breast cancer cells（MDA-MB-231）.Methods：The tube formation ability was assessed using a matrigel basement membrane model,and the structures of the tubular networks were observed under the inverted microscope.Apoptosis cells were stained with Annexin-FITC and PI,and then quantified by fluorescent microscope.Using the broad range caspase inhibitor Z-VAD-FMK and the caspase-3 inhibitor Ac-DEVD-CHO,we further explored the influence of cell apoptosis on forming capillary like structures.Results：MDA-MB-231 cells linked to each other to form wreaths and network structures after 24 h based on three dimensional culture.Capillary-like structures of MDA-MB-231 cells were stained positively with PAS.Apoptosis occurred before capillary-like structure formation but not after capillary-like structures had assembled.Both Z-VAD-FMK and Ac-DEVD-CHO blocked capillary-like structure formation.Conclusion：Breast cancer cells can adopt a capillary-like structure and engage in vasculogenic mimicry.Capillary-like structure formation requires apoptotic cell death through activation of a caspase-dependent mechanism.