论文部分内容阅读
目的:探讨骨髓基质干细胞(bone marrow stromal cells,BMSCs)颅内移植后潜在的恶变致瘤的可能性及机制。方法:选取在20只Sprague-Dawley大鼠体内移植BMSCs实验中发现的3只对侧肢体偏瘫症状逐渐加重的实验大鼠,采用MRI检查其颅内是否发生占位性改变,观察并记录此3只大鼠的生存期;获取死亡大鼠的含瘤脑组织,采用端粒扩增(telemere repeat amplifi cation protocol,TRAP)-PCR-酶联免疫(enzyme-linked immunosorbent assay,ELISA)法检测细胞端粒酶活性,免疫组织化学法检测含瘤脑组织中细胞核增殖抗原(proliferating cell nuclear antigen,PCNA)、巢蛋白(nestin)和胶质纤维酸性蛋白(glial fi brillary acidic protein,GFAP)的表达,蛋白质印迹法检测表皮生长因子受体(epidermal growth factor receptor,EGFR)、血管内皮生长因子(vascular endothelial growth factor,VEGF)和基质金属蛋白酶-9(matrix metalloproteinase-9,MMP-9)的相对表达量。以无瘤正常大鼠脑组织为对照组。结果:20只BMSCs移植大鼠中共有3只实验鼠出现左侧肢体偏瘫且呈进行性加重,3只大鼠的生存期分别为129、174和187d;TRAP-PCR-ELISA结果显示,3只含瘤组织中细胞端粒酶活性均高于无瘤组;免疫组织化学结果显示,3只大鼠含瘤组织中PCNA和nestin的蛋白表达水平均高于无瘤组,GFAP表达水平则低于无瘤组;蛋白印迹法检测结果提示,与无瘤组织比较,3例肿瘤组织中有1只EGFR表达增高,2只VEGF表达增高,而MMP-9表达水平差异均无统计学意义。结论:长期体外培养的BMSCs可出现端粒酶活性和细胞增殖活力增强,以及部分癌基因激活等致瘤表型,提示干细胞体内移植存在潜在的成瘤可能性。
Objective: To investigate the possibility and mechanism of potential malignant tumorigenesis after intracranial transplantation of bone marrow stromal cells (BMSCs). Methods: Three experimental rats with contralateral limb hemiparesis were found in 20 Sprague-Dawley rats. The lesions in the skull were observed by MRI and recorded. The survival time of the rats was measured. Tumor-bearing brain tissues of the deceased rats were harvested, and the cell terminals were detected by TRAP (enzyme-linked immunosorbent assay) Granulocyte activity and immunohistochemistry were used to detect the expression of proliferating cell nuclear antigen (PCNA), nestin and glial fibrillary acidic protein (GFAP) The relative expression levels of epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) were detected by Western blotting. Tumor-free normal rat brain tissue as a control group. Results: Three limbs of 20 BMSCs transplanted rats showed progressive hemiplegia on the left limb. The survival time of the three rats was 129, 174 and 187 days respectively. TRAP-PCR-ELISA showed that 3 rats The telomerase activity in tumor-bearing tissues was higher than that in tumor-free group. Immunohistochemistry showed that the protein expression levels of PCNA and nestin in tumor-bearing tissues of three rats were higher than those in tumor-free group, while the expression of GFAP was lower than The results of Western blotting showed that the expression of EGFR in one of the three tumor tissues was increased and the expression of VEGF in the two tumors was increased compared with the tumor-free tissues. However, the expression of MMP-9 had no statistical significance. CONCLUSION: Long-term in vitro cultured BMSCs exhibit telomerase activity and enhanced cell proliferation activity as well as tumorigenic phenotypes such as activation of some oncogenes, suggesting potential potential for tumorigenesis of stem cells in vivo.