Objective: To investigate the inhibitory effects of nucleolar and spindle associated protein 1 (NUSAP1) on lung cancer and the related mechanisms. Methods: A549 cells were transfected with NUSAP1 siRNA, the cell proliferation, migration and invasion, and apoptosis were detected by CCK8, Transwell and flow cytometry, respectively. Western blot was used to detect the expressions of apoptosis and AKT/mTOR signal pathway related proteins. Results: Compared with the negative control group, the proliferation [(0.610±0.058) vs (1.724±0.067), P<0.05], migration [(178.267±14.780) vs (272.464±36.232), P<0.05] and invasion [(73.527±6.617) vs (120.585±13.235), P<0.05] of NUSAP1 deleted A549 cells were significantly inhibited, while the apoptosis [(3.572±0.214)% vs (11.358±1.047)%, P<0.05] was significantly increased. The expressions of apoptosis related protein Bax and active-caspase 3 were increased (P<0.05), while the expressions of anti-apoptosis protein Bcl-2 and proliferation related protein P70, the phosphorylation levels of AKT and mTOR were reduced in NUSAP1 knockdown cells (P<0.05). Conclusion: NUSAP1 knockdown can inhibit the proliferation, migration and invasion, and promote the apoptosis of tumor cells through suppressing AKT/mTOR signaling pathway in lung cancer cells.
目的： 探讨核仁纺锤体相关蛋白1 (NUSAP1)在肺癌中的作用及其相关机制。 方法： 利用小RNA干扰技术敲低肺癌细胞系A549中NUSAP1的表达。采用CCK－8、Transwell法和流式细胞术检测细胞增殖、迁移和侵袭以及细胞凋亡的情况，采用Western blot检测凋亡相关基因和AKT/mTOR信号通路相关蛋白。 结果： 与阴性对照组比较，敲低NUSAP1表达后，A549细胞的吸光度(A)值降低(分别为1.724±0.067和0.610±0.058，P<0.05)，细胞迁移数降低[分别为(272.464±36.232)个和(178.267±14.780)个，P<0.05]，细胞侵袭数目降低[分别为(120.585±13.235)个和(73.527±6.617)个，P<0.05]，而细胞凋亡率明显增加[分别为(3.572±0.214)%和(11.358±1.047)%，P<0.05]，抗凋亡蛋白Bcl－2表达量下降，凋亡相关蛋白Bax和active caspase3表达量上升(均P<0.05)。同时，干扰NUSAP1表达后，A549细胞中AKT和mTOR的磷酸化水平受到显著抑制，细胞增殖相关蛋白P70表达水平降低(均P<0.05)。 结论： 敲低NUSAP1的表达，通过抑制AKT/mTOR信号通路抑制肺癌细胞的增殖、迁移和侵袭，促进肿瘤细胞凋亡，进而发挥抑制肺癌的作用。.
Keywords: Cell apoptosis; Cell proliferation; Lung neoplasms; Nucleolar and spindle associated protein 1.