目的： 探讨四环素调控（Tet-on）livin RNA干扰系统对肺癌移植瘤生长的影响，以期寻找更优的肺癌干预调控系统。 方法 : 构建Tet-on livin shRNA慢病毒载体，在裸鼠右上肢背部皮下注射肺腺癌A549株细胞建立肺癌裸鼠皮下移植瘤模型，以 Tet-on livin shRNA慢病毒载体注射瘤体干预livin表达，并以四环素腹腔注射诱导处理，了解Tet-on调控livin RNA干扰效果并观 察其抑制肺癌细胞增殖情况。 结果: 经四环素诱导，Tet-on livin RNA组移植瘤组织中livin蛋白表达明显低于CTL组及Tet-on- NC组，且Tet-on-livin RNA组瘤体质量明显低于CTL组及Tet-on-NC组[ （5.31±0.86）vs（8.22±0.63）、 （7.17±0.54）g，P<0.05]；提示 该调控系统可显著下调livin的表达，并抑制肺癌皮下移植瘤的生长，且该调控系统毒副作用小，未发现裸鼠死亡。 结论: Tet-on livin RNA干扰系统在四环素诱导下可抑制肺癌生长，具有靶向性、可调控的特点，为以livin蛋白为靶点的肺癌靶向治疗研究提 供重要的研究工具。

Objective: To investigate he effect of tetracycline- (Tet-on) mediated livin RNA interference on growth of lung carcinoma xenegrafts, and find a better regulatory way to interfere the development on lung cancer. Methods: livin shRNA lentiviral vectors were constructed; and the lung cancerA549 cells were subcutaneously injected into right upper back of nude mice to establish xenegraft mod- el. The livin shRNA lentiviral vectors were injected into xenografts to interfere the expression of livin, then tetracycline was injected in- traperitoneally for the induction. The suppressive effect of Tet-on mediated livin RNA interference efficiency was investigated and lung cancer xenograft development was observed. Results: After the induction with Tet-on, livin gene expression was significantly inhibited by livin shRNA compared with the control group and Tet-on-NC group; the xenograft volume in Tet-on- livin shRNA group was signifi- cantly smaller than that in control group and Tet-on-NC group ([5.31±0.86]g vs [8.22±0.63]g and [7.17±0.54] g, P<0.05). Moreover, lit- tle body toxicity was observed and no nude mice died in this study. Conclusion: The Tet-on mediated livin shRNA could suppress the growth of lung cancer development with good targeting and controllable characteristics, which might provide a potent tool for treating lung cancer with livin protein as target.

福建省自然科学基金资助项目（No. 2015J01376）；福建 省立医院优秀青年医师项目 (No. 2014YNQN03)。