PTTG1促进结肠癌SW480细胞侵袭和迁移的作用机制

Effect of PTTG1 Expression on Invasion and Migration of Colon Cancer Cell SW480 and Its Possible Mechanism

目的研究垂体肿瘤转化基因1(pituitary tumor transforming gene 1,PTTG1)过表达促进人结肠癌细胞SW480侵袭和迁移作用及其可能机制。方法采用脂质体转染法将pc DNA3.1(+)-PTTG1及空载pc DNA3.1(+)转染人结肠癌SW480细胞,G418法筛选阳性克隆。Western blot和Real-time PCR法鉴定稳定过表达PTTG1细胞株建立。Transwell小室法检测细胞侵袭和迁移能力,Western blot检测MMP2、MMP9、E-cadherin、Vimentin和Snail的表达。结果 (1)成功获得稳定高表达PTTG1的SW480克隆细胞株PTTG1-SW480;(2)过表达PTTG1基因后,SW480细胞侵袭和迁移能力增强,MMP2和MMP9表达升高,上皮间质转化(epithelial-mesenchymal transition,EMT)标记分子E-cadherin表达降低,Vimentin和Snail的表达升高,差异均有统计学意义(P<0.01);(3)过表达PTTG1基因后,SW480细胞中PI3K/AKT信号活化增强,使用LY29400干预后,抑制细胞侵袭、迁移和EMT,E-cadherin表达上调、Vimentin和Snail的表达下调,差异均有统计学意义(P<0.01)。结论 PTTG1基因过表达可能通过活化PI3K/AKT信号诱导SW480细胞EMT发生,发挥促进SW480侵袭和迁移作用;提示PTTG1蛋白可能成为结肠癌治疗的一个潜在靶点。

Objective To investigate the effect of over-expression of pituitary tumor transforming gene 1 （PTTG1） on the invasion and migration of human colon cancer cells SW480 and its possible mechanism. Methods Both pcDNA3.1（＋）-PTTGland pcDNA3.1（＋） plasmids were separately transfected into human colon cancer cell line SW480 by liposome transfection method and G418 was used to screen positive clones. Real-time PCR and Western blot were used to asses the stably over-expressed PTTG1 in PTTG1-SW480. The abilities of migration and invasion of PTTG1-SW480 cells were assayed by Transwell chambers and Western blot was used to detect the expression of MMP2, MMP9, E-cadherin, Vimentin and Snail. Results （1） The cloned cells PTTG1-SW480 with PTTG1 over-expression were successfully obtained; （2） After PTTG1 over- expression, the abilities of migration and invasion of SW480 cells were enhanced, the expression of MMP2 and MMP9 were up-regulated, Vimentin and Snail expression were up-regulated, and E-cadherin expression was down-regulated （all P〈0.01）; （3） The signaling pathway of PI3FUAKT activation was enhanced in PTTGl-SW480 cells. Interfering with LY29400, the abilities of migration and invasion and EMT of PTTG1- SW480 cells were prevented, the expression of E-cadherin was up-regulated and Vimentin and Snail expression were down-regulated （all P〈0.01）. Conclusion PTTG1 over-expression may promote SW480 cells migration and invasion through activating PI3K/AKT pathway to induce EMT. PTTG1 may become a potential target for colon cancer treatment.