Cancer Drug Resistance Laboratory, Department of Life, Science, National Institute of Technology, Rourkela, Odisha, 769008, India.
Mol Biol Rep. 2020 Jun;47(6):4155-4168. doi: 10.1007/s11033-020-05464-w. Epub 2020 May 22.
Plumbagin (PL) is a natural naphthoquinone compound, isolated from Plumbago zeylanica that has cytotoxic and antimigratory potential in many cancer. However, the cytotoxic mechanism of plumbagin in drug resistant lung cancer is poorly understood. To reveal the mechanism, we studied the anticancer effect of plumbagin in both gefitinib-sensitive and resistant A549 lung cancer cells. The anticancer potential of PL was demonstrated by MTT assay and the result suggested that PL showed cytotoxicity in both gefitinib-sensitive (A549) and gefitinib-resistant (A549GR) lung cancer cells. IC values of PL in A549 and A549GR were 3.2 μM and 4.5 μM, respectively. Morphological changes were also observed after treatment with PL. Furthermore, PL decreased cell survival by inhibiting colony formation ability, and inhibited cell migration at very low concentrations. From Annexin V-FITC/PI, AO/EtBr, and DAPI staining, we found that increasing concentration of PL leads to increase in apoptosis of lung cancer cells. Furthermore, western blotting results suggested that Bax and Caspase 3 levels were upregulated after PL treatment. In addition, treatment of PL caused DNA damage in a dose-dependent manner. PL arrested the cell cycle at S-GM phase, and enhanced reactive oxygen species (ROS) generation. Excess ROS generated by PL disrupted mitochondrial membrane resulted in depletion of mitochondrial membrane potential (MMP). These results conclude that PL decreases lung cancer cell viability by arresting cells at S-GM phase, and induces apoptosis by activation of mitochondrial-mediated apoptotic pathway through excess ROS generation. Overall findings suggest that plumbagin shows cytotoxic and therapeutic potential against both A549 and A549GR cell lines.
白花丹素（PL）是一种天然萘醌化合物，从白花丹中分离出来，在许多癌症中具有细胞毒性和抗迁移作用。然而，白花丹素在耐药性肺癌中的细胞毒性机制尚不清楚。为了揭示这种机制，我们研究了白花丹素在吉非替尼敏感和耐药的 A549 肺癌细胞中的抗癌作用。MTT 检测法显示 PL 具有抗癌潜力，结果表明 PL 对吉非替尼敏感（A549）和吉非替尼耐药（A549GR）肺癌细胞均具有细胞毒性。PL 在 A549 和 A549GR 中的 IC 值分别为 3.2 μM 和 4.5 μM。用 PL 处理后还观察到形态变化。此外，PL 通过抑制集落形成能力降低细胞存活率，并在非常低的浓度下抑制细胞迁移。通过 Annexin V-FITC/PI、AO/EtBr 和 DAPI 染色，我们发现 PL 浓度增加会导致肺癌细胞凋亡增加。此外，Western blot 结果表明，PL 处理后 Bax 和 Caspase 3 水平上调。此外，PL 处理以剂量依赖性方式引起 DNA 损伤。PL 将细胞周期阻滞在 S-GM 期，并增强活性氧（ROS）的产生。PL 产生的过量 ROS 破坏线粒体膜，导致线粒体膜电位（MMP）耗竭。这些结果表明，PL 通过将细胞阻滞在 S-GM 期来降低肺癌细胞活力，并通过过量 ROS 生成激活线粒体介导的凋亡途径诱导细胞凋亡。总的来说，这些发现表明白花丹素对 A549 和 A549GR 细胞系均具有细胞毒性和治疗潜力。
