中文摘要：

目的 观察抑制骨桥蛋白（OPN）表达对肺癌细胞株A549侵袭、增殖的影响.方法 构建针对人OPN mRNA干扰质粒pENTR^TM/U6-INF（pINF-1）及对照质粒pENTR^TM/U6-CTR（pCTR）,将其转染A549细胞.Western blot测定OPN的表达;噻唑蓝（MTY）比色法检测A549增殖力;Matrigel侵袭实验检测细胞侵袭力的改变.结果 与空白对照组（1.23±0.16）比较,转染72 h后pINF-1组OPN蛋白表达（0.17±0.07）下降85%;转染 pINF-1后,A549细胞增殖力下降56%,与对照组比较差异有统计学意义（P〈0.05）.Matrigel实验示,与空白对照组（72.4±6.5）比较,转染pINF-1组细胞穿过人工基底膜的数量（15.2±2.8）明显减少,差异有统计学意义（P〈0.01）.结论 pINF-1可以特异性抑制肺癌细胞株A549中OPN的表达,可显著降低其侵袭力和增殖.

英文摘要：

Objective To develop DNA vector-based RNA interference （RNAi） technology and block the expression of osteopontin （OPN） in lung cancer cell line A549 ,and further examine its possible effect on invasion and proliferation of lung cancer cells. Methods One double-stranded DNA vectors pEN-TRTM/U6-INF （pINF-1） targeting the mRNA of human OPN, and the control vector pENTRTM/U6-CTR （pCTR） mismatching with mRNA of OPN were constructed, and then they were transfected into human A549 cells with high metastatic potentials. Western blotting was used to quantify the protein level of OPN. The malignant phenotypes of transfected A549 cells including proliferation and invasive activities were ana-lyzed. Results As compared with control group only transfected with Lipofectamine^TM 2000, OPN protein lev-el in plNF-1 group could be decreased by 85% 72 h after transfection,and no significant difference was found in the group transfected with pCTR. In vitro cellular growth rate was decreased by 56% （P〈0.05） in the group transfected with pINF-1 ,and migrating number of A549 cells （15.2±2.8） transfected with pINF-1 was also significantly decreased （P〈0.01 ） as compared with the control group （72.4±6.5）. Conclusion Se-quence-specific shRNA （pINF-1） can significantly reduce the OPN expression in A549 cell line. The sup-pression of OPN expression in A549 cells transfected with pINF-1 can induce the decline of invasive and pro-liferative ability of A549. This suggests that OPN may be an alternative target for treatment in lung cancer.