血管内皮诱导培养基促进结肠癌细胞向血管内皮细胞方向分化的研究

Research of colon cancer stem cell-like cells induced to differentiate into vascular endothelial cells

目的:探讨结肠癌细胞在血管内皮诱导环境下向血管内皮细胞方向分化的潜能。方法:将3种不同分化程度的结肠癌细胞HCT116、SW480和HT29分别置于含有内皮细胞诱导因子的条件培养基中培养15 d后,利用Western blot检测血管内皮特异性指标白细胞分化抗原31(cluster of differentiation 31,CD31)和白细胞分化抗原34(cluster of differentiation 34,CD34)的表达变化;利用细胞免疫荧光检测HCT116细胞在内皮诱导培养基及普通培养基中CD31、CD34的表达变化;通过三维培养观察内皮诱导培养基对HCT116细胞体外成管能力的影响。结果:Western blot显示诱导培养15 d后的3种细胞中低分化HCT116细胞的CD31、CD34表达增强最明显,而中分化的SW480细胞和高分化的HT29变化不显著。细胞免疫荧光显示与普通培养基相比,内皮诱导培养基中HCT116细胞的CD31、CD34表达显著增强。体外三维培养发现经内皮诱导培养后的HCT116细胞较对照细胞成管能力显著增强。结论:血管内皮诱导培养基促进具有较强干细胞样特性的结肠癌细胞向血管内皮细胞方向分化。

Objective：This study aims to investigate the potential of colon cancer cells to differentiate into vascular endothelial cells in endothelial-induced specific environment. Methods：Three colon cancer cells with different differentiated level HCT116 （poor-ly differentiated）, SW480 （moderately differentiated）, HT29 （well differentiated） were cultured in the conditioned medium containing the endothelial-inducing factors for 15 days respectively. The expression of vascular endothelial indicators Platelet endothelial cell adhe-sion molecule-1、Endothelial cell adhesion molecule CD34 was detected via western blot. Immunofluorescence staining was performed to examine CD31 and CD34 expression level in HCT116 after cultured in endothelial-inducing medium and ordinary medium for 15 days respectively, and the three-dimensional （3D） culture was used to detect the abililty of in vitro tube-like structure formation. Re-sults：Western blot showed that CD31 and CD34 expression level were negatively correlated with degree of differentiation in colon can-cer cells. CD31 and CD34 expression in endothelial-inducing medium HCT116 cells （poorly differentiated） were higher then in the nor-mal medium, while the CD31 and CD34 expression in SW480 cells （moderately differentiated） and HT29 cells （well differentiated） in the two cultural mediums were not notably changed. Immunofluorescence staining illustrated that CD31 and CD34 expression in HCT116 cells cultured in endothelial-inducing medium increased compared with those cultured in ordinary medium. In vitro three-di-mensional culture demonstrated that ability of tube-like structure formation was notably enhanced after endothelial-inducing cultured. Conclusion：Endothelial-inducing medium could promote colon cancer cells with strong stemness differentiate toward vascular endo-thelial cells.