Department of Respiratory and Critical Care Medicine, Zibo First Hospital, Zibo 255200, Shandong, China.
J BUON. 2020 Jan-Feb;25(1):248-254.
Lung cancer is one of the deadly diseases with limited treatment options available. The main aim of the current study was to investigate the antitumor effects of levopimaric acid - a naturally occurring diterpene, against cisplatin-resistant non-small cell lung carcinoma cells A-549 and normal MRC5 cells. Effects of levopimaric acid on autophagy, reactive oxygen species (ROS), apoptosis and ERK/MAPK signalling pathways were also investigated in the current study.
Proliferation rate was monitored by MTS assay. Apoptosis was detected by DAPI staining as well as western blot assay. Electron microscopy was used to investigate the autophagic effects of levopimaric acid. Effects on ROS and mitochondrial membrane potential (MMP) were evaluated by flow cytometry. Protein expression was examined by western blotting.
It was found that levopimaric acid exerts potent antiproliferative effects against the cisplatin-resistant lung cancer cells and exhibited an IC50 of 15 μM. However, the toxic effects of levopimaric acid were seen to be insignificant against the normal cells. The anticancer effects of levopimaric acid were due to induction of apoptosis which was also associated with modulation of apoptosis-related proteins (Bax and Bcl-2). Levopimaric acid also induced autophagy which was also associated with alterations of autophagy-related protein expressions (LC3I, II, and p62). Levopimaric acid caused ROS-mediated alterations in the MMP. It was also found that the molecule could induce drug-resistant lung cancer cell death by activating p38 MAPK and JNK signalling pathways while inhibiting ERK pathway.
The current results strongly indicate that levopimaric acid may prove to be a potential anticancer drug candidate provided further in depth studies are carried out.
肺癌是一种致命疾病，治疗选择有限。本研究的主要目的是研究左旋扁柏酸（一种天然二萜）对顺铂耐药非小细胞肺癌 A-549 细胞和正常 MRC5 细胞的抗肿瘤作用。本研究还研究了左旋扁柏酸对自噬、活性氧（ROS）、细胞凋亡和 ERK/MAPK 信号通路的影响。
通过 MTS 测定法监测增殖率。通过 DAPI 染色和 Western blot 分析检测细胞凋亡。电子显微镜用于研究左旋扁柏酸对自噬的影响。通过流式细胞术评估 ROS 和线粒体膜电位（MMP）的影响。通过 Western blot 检测蛋白表达。
研究发现，左旋扁柏酸对顺铂耐药肺癌细胞具有强大的增殖抑制作用，其 IC50 为 15 μM。然而，左旋扁柏酸对正常细胞的毒性作用不明显。左旋扁柏酸的抗癌作用是由于诱导细胞凋亡所致，这也与凋亡相关蛋白（Bax 和 Bcl-2）的调节有关。左旋扁柏酸还诱导自噬，这也与自噬相关蛋白表达的改变（LC3I、II 和 p62）有关。左旋扁柏酸引起 ROS 介导的 MMP 改变。还发现该分子通过激活 p38 MAPK 和 JNK 信号通路，同时抑制 ERK 通路，诱导耐药性肺癌细胞死亡。
目前的结果强烈表明，左旋扁柏酸可能成为一种有潜力的抗癌药物候选物，但需要进一步深入研究。
