Department of Biotechnology, Daegu University, Gyeongsan, Gyeongbuk, 38453, Republic of Korea.
Mech Ageing Dev. 2021 Jun;196:111497. doi: 10.1016/j.mad.2021.111497. Epub 2021 May 3.
Cell-cycle arrest reflects an accumulation of responses to DNA damage that sequentially affects cell growth and division. Herein, we analyzed the effect of the 9-mer dimer defensin-like peptide, CopA3, against colorectal cancer cell growth and proliferation in a dose-dependent manner upon 96 h of treatment. As observed, CopA3 treatment significantly affected cancer cell growth, reduced colony formation ability, increased the number of SA-β-Gal positive cells, and remarkably reduced Ki67 protein expression. Notably, in HCT-116 cells, CopA3 (5 μM) treatment effectively increased oxidative stress and, as a result, amplified the endogenous ROS, mitochondrial ROS, and NO content in the cells, which further activated the DNA damage response and caused cell-cycle arrest at the G1 phase. The prolonged cell-cycle arrest elevated the release of inflammatory cytokines in the cell supernatant. Nevertheless, mechanistically, NAC treatment effectively reversed the CopA3 effect and significantly reduced the oxidative stress; subsequently rescuing the cells from G1 phase arrest. Overall, CopA3 treatment can inhibit the growth and proliferation of colorectal cancer cells by inducing cell-cycle arrest through the ROS-mediated pathway.
细胞周期停滞反映了对 DNA 损伤的一系列反应的积累，这些反应会依次影响细胞的生长和分裂。在此，我们分析了 9 聚体二聚防御素样肽 CopA3 对结直肠癌细胞生长和增殖的影响，结果表明，CopA3 处理在 96 小时的治疗过程中以剂量依赖性方式显著影响癌细胞生长，降低集落形成能力，增加 SA-β-Gal 阳性细胞数量，并显著降低 Ki67 蛋白表达。值得注意的是，在 HCT-116 细胞中，CopA3（5 μM）处理有效增加了氧化应激，从而放大了细胞内的内源性 ROS、线粒体 ROS 和 NO 含量，进一步激活了 DNA 损伤反应，并导致细胞周期停滞在 G1 期。延长的细胞周期停滞增加了细胞上清液中炎症细胞因子的释放。然而，从机制上讲，NAC 处理可有效逆转 CopA3 的作用，并显著降低氧化应激，从而使细胞从 G1 期阻滞中恢复。总之，CopA3 处理可通过 ROS 介导的途径诱导细胞周期停滞来抑制结直肠癌细胞的生长和增殖。
