Cardiology and Molecular Imaging Department, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China.
Mol Carcinog. 2013 Nov;52(11):900-7. doi: 10.1002/mc.21930. Epub 2012 Jun 5.
Cisplatin is a commonly employed chemotherapy drug for lung malignancy. However its efficacy is limited by acquired drug resistance and lacking of an in vivo real-time monitoring approach. The aim of this study is to investigate the effect of cisplatin on lung adenocarcinoma cell line p53-RE-Fluc/A549 in vivo via non-invasive reporter gene by molecular imaging. For this study, we employed p53-RE-Fluc/A549 cells that overexpressed a vector with three tandem repeats of p53 response element followed by the luciferase reporter gene. P53 activity was evaluated by optical imaging and verified by Western blot after cells were exposed to 10 µM cisplatin for 72 h. The cell cycle was mainly blocked at the S- and G2/M-phases after cisplatin treatment, whereas no significant change was observed in cell apoptotic index. Increased expression of p21 and Bcl-2 as well as decreased expression of Bax were observed after cisplatin treatment by Western blotting. Longitudinal in vivo bioluminescent imaging (BLI) revealed that the p53 activity was increased from 24 to 48 h after transient cisplatin treatment in p53-RE-Fluc/A549-bearing nude mice. RNA sequencing further revealed that cell cycle and p53 signaling pathway genes, such as E2F1, CCNA2, CDK1, and CCNE2 were significantly downregulated after long-term cisplatin treatment. Thus, our study showed that cisplatin exerts its cytotoxic effect through blockage of the cell cycle and may be partly regulated by the p53 signaling pathway. Furthermore, molecular imaging is a useful tool to investigate the mechanism and evaluate the effect of chemotherapy drugs both in vivo and in vitro.
顺铂是一种常用于治疗肺癌的化疗药物。然而，它的疗效受到获得性耐药性的限制，并且缺乏体内实时监测方法。本研究旨在通过分子影像学研究非侵入性报告基因，研究顺铂对肺腺癌细胞系 p53-RE-Fluc/A549 的体内作用。在这项研究中，我们使用了过表达含有三个串联 p53 反应元件的载体以及荧光素酶报告基因的 p53-RE-Fluc/A549 细胞。通过光学成像评估 p53 活性，并在细胞暴露于 10 μM 顺铂 72 小时后通过 Western blot 进行验证。顺铂处理后，细胞周期主要在 S 和 G2/M 期被阻断，而细胞凋亡指数没有明显变化。Western blot 结果显示，顺铂处理后 p21 和 Bcl-2 表达增加，Bax 表达减少。纵向体内生物发光成像（BLI）显示，p53-RE-Fluc/A549 荷瘤裸鼠在短暂顺铂处理后 24 至 48 小时内 p53 活性增加。RNA 测序进一步显示，细胞周期和 p53 信号通路基因，如 E2F1、CCNA2、CDK1 和 CCNE2，在长期顺铂处理后显著下调。因此，我们的研究表明，顺铂通过阻断细胞周期发挥其细胞毒性作用，并且可能部分受 p53 信号通路调节。此外，分子成像为研究化疗药物的作用机制和体内外疗效提供了一种有用的工具。
