脂肪组织来源的干细胞体外培养随机恶性转化

Adipose tissue-derived stem cells transform malignantly in vitro spontaneously

目的研究脂肪来源干细胞在体外能否恶性转化。方法从小鼠脂肪组织培养出脂肪组织来源干细胞(ADSCs),观察细胞是否发生恶性转化,应用免疫细胞化学方法检测转化细胞的相关标志物的表达,并对其染色体结构进行分析,并将转化细胞移植到裸鼠皮下以检测其成瘤性。结果 1个培养瓶中的细胞在体外培养4个月左右发生了转化,已经永生化,目前体外培养超过100代,细胞仍维持原来的增殖速度。细胞表达中胚层的标志物vimentin,但不表达pan-CK,说明其是间充质来源;同时表达PCNA、Ki67和VEGF-c,不表达p16;染色体分析证明为非整倍体,有广泛的易位;透射电镜下可见细胞表面微绒毛结构;细胞在软琼脂中没有克隆形成能力;裸鼠皮下移植能够形成肿瘤组织,肿瘤组织的主体成分为肉瘤。结论脂肪组织来源的干细胞在体外长期培养能够发生恶性转化,裸鼠皮下移植能够形成肉瘤。

Objective To study adipose tissue-derived stem cells （ADSCs） whether malignant transformation in vitro. Methods ADSCs were isolated and cultured from adipose tissues of mice, which were observed whether to occur malignant transformation. The tissue-specific markers of transformed cells were detected by immunocytochemistry, and the chromosome structure were analyzed. The transformed cells were transplanted into nude mice to investigate their tumorigenicity. Results A flask of ADSCs were successively cultured for 4 months and a number of cells had transformed and immortalized in vitro. The ADSCs were cultured more than 100 generations and still maintained the original cell proliferation rate. The marker of vimentin, PCNA, Ki67 and VEGF-c were expressed but the pan-CK and p16 were not expressed, which showed the cells were mesenchymal origin. Meanwhile, the chromosome analysis showed all cells were aneuploidy and translocation were very common. Microvilli structure of cell surface could be observed by transmission electron microscopy. There was no clone formation ability of transformed ADSCs in soft agar media. Nude mice subcutaneously transplanted could form tumor tissue that the main component was sarcoma. Conclusion Adipose tissue-derived stem cells could malignantly transformed spontaneously in vitro, and which also could form tumors in nude mice after transplantation.