To investigate the effect of manganese superoxide dismutase (MnSOD) silence on the in vitro tumorigenicity in human small cell lung cancer NCI-H446 cells and the underlying mechanisms. Methods: Sphere formation cells from NCI-H446 cells were obtained by suspension culture, while the expression of MnSOD and urokinase type plasminogen activator (uPAR) was analyzed by Western blot. Silence of MnSOD was performed by adenovirus infection in the second passage formation cells, and the effect of MnSOD silence on tumorigenicity in NCI-H446 cells was evaluated by sphere formation assay and soft-agar colony formation assay, while the expression of uPAR was analyzed by Western blot. Results: Compared with NCI-H446 cells, the sphere formation rate, colony formation rate, and the expression of MnSOD and uPAR were significantly increased in the second passage sphere formation cells in NCI-H446 cells (P<0.05). Silence of MnSOD inhibited the sphere formation rate, colony formation rate, and the expression level of uPAR in the second passage sphere formation cells in NCI-H446 cells. Conclusion: MnSOD may promote tumorigenicity in NCI-H446 cells by up-regulation of uPAR expression in vitro.
目的：研究锰超氧化物歧化酶(manganese superoxide dismutase，MnSOD)沉默对人小细胞肺癌NCI-H446细胞系球细胞体外致瘤性的影响及其潜在的机制。方法：采用悬浮培养法得到人小细胞肺癌NCI-H446细胞系球细胞，用Western印迹分析MnSOD和尿激酶型纤溶原酶激活物(urokinase type plasminogen activator，uPAR)表达。利用腺病毒感染技术沉默NCI-H446细胞MnSOD，球形成法和软琼脂集落形成法评价MnSOD沉默对NCI-H446球细胞体外致瘤性的影响，用Western印迹检测uPAR的表达。结果：与NCI-H446细胞比较，NCI-H446细胞第2代球细胞的球形成率和集落形成率及MnSOD和uPAR表达明显增加(P<0.05)。表达shMnSOD的腺病毒抑制NCI-H446细胞第2代球细胞球形成率、集落形成率及uPAR的表达。结论：MnSOD可能通过调控uPAR表达维持小细胞肺癌NCI-H446细胞系球细胞的体外高致瘤性。.