Department of Physiology, Medical School, Research Institute for Endocrine Sciences, Chonbuk National University, Jeonju, Jeollabuk 54907, Republic of Korea.
Oncol Rep. 2018 Sep;40(3):1787-1794. doi: 10.3892/or.2018.6535. Epub 2018 Jun 28.
Hydrogen peroxide (H2O2) is frequently applied to cultured cells to induce oxidative stress. The present study investigated the molecular and cellular effects of exogenous H2O2 on Calu‑6 and A549 lung cancer cells. Based on MTT assays, H2O2 inhibited the growth of Calu‑6 and A549 cells with IC50 values of ~50 and 100 µM at 24 h, respectively. Cells treated with H2O2 demonstrated a considerable G1‑phase arrest of the cell cycle. H2O2 dose‑dependently augmented the numbers of dead (trypan blue‑positive) and Annexin V‑FITC‑stained cells in these cells, which was accompanied by the reduction of Bcl‑2 and pro‑caspase‑3 levels, as well as the upregulation of caspase‑3 and ‑8 activities. In addition, H2O2 triggered the failure of mitochondrial membrane potential (MMP; ΔΨm). However, relatively higher doses of H2O2 did not raise the percentages of sub‑G1 cells in these cell lines. All the tested caspase inhibitors (Z‑VAD for pan‑caspases, Z‑DEVD for caspase‑3, Z‑IETD for caspase‑8 and Z‑LEHD for caspase‑9) decreased the percentages of sub‑G1 and Annexin V‑FITC‑stained cells in the H2O2‑treated Calu‑6 and A549 cells. However, caspase inhibitors did not significantly prevent the loss of MMP (ΔΨm) in H2O2‑treated lung cancer cells. In conclusion, H2O2 inhibited the growth of Calu‑6 and A549 lung cancer cells through cell death and G1‑phase arrest. H2O2‑induced cell death resulted from necrosis, as well as caspase‑dependent apoptosis.
过氧化氢（H2O2）常用于培养细胞以诱导氧化应激。本研究探讨了外源性 H2O2 对 Calu-6 和 A549 肺癌细胞的分子和细胞效应。基于 MTT 测定，H2O2 在 24 小时时分别以约 50 和 100 µM 的 IC50 值抑制 Calu-6 和 A549 细胞的生长。用 H2O2 处理的细胞显示出细胞周期 G1 期的明显停滞。H2O2 剂量依赖性地增加了这些细胞中死亡（台盼蓝阳性）和 Annexin V-FITC 染色细胞的数量，同时伴随着 Bcl-2 和前半胱天冬酶-3 水平的降低，以及半胱天冬酶-3 和 -8 活性的上调。此外，H2O2 引发了线粒体膜电位（MMP；ΔΨm）的衰竭。然而，这些细胞系中相对较高剂量的 H2O2 并未增加亚 G1 细胞的百分比。所有测试的半胱天冬酶抑制剂（Z-VAD 用于 pan-caspases，Z-DEVD 用于 caspase-3，Z-IETD 用于 caspase-8 和 Z-LEHD 用于 caspase-9）降低了 H2O2 处理的 Calu-6 和 A549 细胞中亚 G1 和 Annexin V-FITC 染色细胞的百分比。然而，半胱天冬酶抑制剂并没有显著阻止 MMP（ΔΨm）在 H2O2 处理的肺癌细胞中的丧失。总之，H2O2 通过细胞死亡和 G1 期停滞抑制 Calu-6 和 A549 肺癌细胞的生长。H2O2 诱导的细胞死亡既来自坏死，也来自半胱天冬酶依赖性凋亡。
