人骨肉瘤细胞株MG-63中肿瘤干细胞的生物学特性

背景：骨肉瘤干细胞在骨肉瘤的发生、复发及对化疗药物的耐药性中发挥关键作用,而目前关于骨肉瘤干细胞体外分离培养及生物学特性研究的报道甚少。目的：从人骨肉瘤细胞株MG-63中分离出具有干细胞特征的高致瘤性细胞亚群,检测肿瘤干细胞特异性标志物CD105的表达。方法：无血清悬浮培养法从人骨肉瘤细胞株MG-63中分离出骨肉瘤细胞球,应用流式细胞术检测细胞球中CD73、CD90、CD105的表达,免疫荧光法检测骨肉瘤细胞株及骨肉瘤细胞球中CD105的阳性率,免疫磁珠法分选出CD105＋和CD105-的细胞,传代后分别接种于NOD/SCID小鼠评估其致瘤性。结果与结论：CD105在球体细胞中高表达,此类肿瘤细胞具有高侵袭性和高致瘤性,在NOD-SCID小鼠中仅需移植1000个细胞即可形成肿瘤,这些细胞具有自主生长特性,能够在无血清条件下长期培养,CD105＋骨肉瘤细胞显示了干细胞的生物学特性,CD105可能成为骨肉瘤干细胞的表面标志之一。

Biological characteristics of tumor stem cells from human osteosarcoma cell line MG-63

BACKGROUND： Osteosarcoma stem cells play a critical role in the occurrence, relapse and drug resistance of osteosarcoma, but there are fewer studies about isolation and culture and biological characteristics of osteosarcoma stem cells in vitro. OBJECTIVE： To isolate the highly tumorigenic sub-populations of cells with stem cell features from the human osteosarcoma cell line MG-63, and to detect the expression of CD105, a specific surface marker of tumor stem cells. METHODS： Osteosarcoma cell spheres were isolated from human osteosarcoma cell line MG-63 with serum-free culturing techniques. The stem cell-related markers CD73, CD90 and CD105 in the osteosarcoma cell spheres were detected by using flow cytometry. Immunofluorescence technique was used for detecting the positive rate of CD105 in MG-63 cell line and osteosarcoma cell spheres. CD105＋ and CD105- cells were separated by magnetic activated cell sorting technique. The tumorigenic potent ofCD105＋ and CD105- cells were evaluated via the transplantation into NOD/SCID mice. RESULTS AND CONCLUSION： The high expression of CD105 was observed in osteosarcoma cell spheres, and these cells possessed the property of high invasiveness and high tumorigenesis. Tumor could be induced in NOD-SCID mice by transplantation of CD105 cells at 1 000 cells per mouse.These cells exhibited autonomous growth features and could be cultured in serum-free condition for a long time. It indicates that osteosarcoma cells with the phenotype of CD105 have stem cell features and CD105 may be one of the surface markers of osteosarcoma stem cells.