中文摘要：

目的：探讨 p53在肺癌 PC-9细胞中对微小 RNA-148b （miR-148b）表达的影响、相应分子机制及对细胞增殖能力的影响。方法：以肺癌PC-9细胞作为研究对象，瞬时转染p53真核表达载体，建立高表达p53的实验模型。通过荧光定量PCR检测p53在PC-9细胞中对miR-148b表达的影响。通过使用miR-148b启动子荧光素酶报告基因表达载体，检测p53对miR-148b 启动子转录活性的影响。通过转染miR-148b 特异性抑制物（Inh-148b）低表达 miR-148b，使用 CCK8法检测 miR-148b 对 p53在肺癌细胞增殖调控过程中的作用。结果：高表达p53可在肺癌PC-9细胞中促进miR-148b的表达；高表达p53可增强miR-148b启动子的活性；低表达miR-148b可减弱p53对肺癌PC-9细胞增殖的抑制作用。结论： p53对肺癌细胞PC-9增殖的抑制作用部分依赖于miR-148b。

英文摘要：

Objective To explore the function of p53 on regulating the expression of miR-148b in lung cancer cell line PC-9 and its corresponding molecular mechanism and the impact on cell proliferation. Methods Transient transfection of p53 eukaryotic expressing plasmids into lung cancer cell line PC-9 was performed to establish a cell model over-expressing p53. RT-PCR was used to explicit the impact of p53 on the expression of miR-148b. A reporter vector containing miR-148b promoter was used to investigate the function of p53 on regulating the transcription of miR-148b. Low-expressing miR-148b by transfecting its specific inhibitors , a CCK-8 assay was performed to explore the influence of miR-148b on the lung cancer cell proliferation inhibited by p53. Results Over-expression of p53 promoted miR-148b expression in lung cancer cell line PC-9. P53 could increase the luciferase activity driven by miR-148b promoters. Knockdown of miR-148b attenuated the impact of p53 on inhibiting the proliferation of PC-9 cells. Conclusion P53 inhibits the proliferation of lung cancer cell line PC-9 partially depending on miR-148b.