Department of Biochemistry, National Defense Medical Center, Taipei City 114, Taiwan.
School of Dentistry, Department of Dentistry of Tri-Service General Hospital, National Defense Medical Center, Taipei City 114, Taiwan.
Int J Mol Sci. 2021 Apr 2;22(7):3711. doi: 10.3390/ijms22073711.
Disulfiram (DSF), an irreversible aldehyde dehydrogenase inhibitor, is being used in anticancer therapy, as its effects in humans are known and less adverse than conventional chemotherapy. We explored the potential mechanism behind the cytotoxicity of DSF-Cu/Cu complexes in oral epidermoid carcinoma meng-1 (OECM-1) and human gingival epithelial Smulow-Glickman (SG) cells. Exposure to CuCl or CuCl slightly but concentration-dependently decreased cell viability, while DSF-Cu/Cu induced cell death in OECM-1 cells, but not SG cells. DSF-Cu/Cu also increased the subG1 population and decreased the G1, S, and G2/M populations in OECM-1 cells, but not SG cells, and suppressed cell proliferation in both OECM-1 and SG cells. ALDH enzyme activity was inhibited by CuCl and DSF-Cu/Cu in SG cells, but not OECM-1 cells. ROS levels and cellular senescence were increased in DSF-Cu/Cu-treated OECM-1 cells, whereas they were suppressed in SG cells. DSF-Cu/Cu induced mitochondrial fission in OECM-1 cells and reduced mitochondrial membrane potential. CuCl increased but DSF- Cu impaired oxygen consumption rates and extracellular acidification rates in OECM-1 cells. CuCl stabilized HIF-1α expression under normoxia in OECM-1 cells, and complex with DSF enhanced that effect. Levels of c-Myc protein and its phosphorylation at Tyr58 and Ser62 were increased, while levels of the N-terminal truncated form (Myc-nick) were decreased in DSF-Cu/Cu-treated OECM-1 cells. These effects were all suppressed by pretreatment with the ROS scavenger NAC. Overexpression of c-Myc failed to induce HIF-1α expression. These findings provide novel insight into the potential application of DSF-CuCl complex as a repurposed agent for OSCC cancer therapy.
双硫仑（DSF）是一种不可逆的醛脱氢酶抑制剂，目前被用于癌症治疗，因为其在人体内的作用已被充分了解，且其副作用小于传统化疗。我们探讨了 DSF-Cu/Cu 复合物在口腔表皮样癌细胞（OECM-1）和人牙龈上皮 Smulow-Glickman（SG）细胞中产生细胞毒性的潜在机制。暴露于 CuCl 或 CuCl 可轻微但浓度依赖性地降低细胞活力，而 DSF-Cu/Cu 诱导 OECM-1 细胞死亡，但不诱导 SG 细胞死亡。DSF-Cu/Cu 还增加了 OECM-1 细胞的亚 G1 群体，减少了 G1、S 和 G2/M 群体，但对 SG 细胞没有影响，并抑制了 OECM-1 和 SG 细胞的增殖。ALDH 酶活性在 SG 细胞中被 CuCl 和 DSF-Cu/Cu 抑制，但在 OECM-1 细胞中没有被抑制。ROS 水平和细胞衰老在 DSF-Cu/Cu 处理的 OECM-1 细胞中增加，而在 SG 细胞中被抑制。DSF-Cu/Cu 诱导 OECM-1 细胞中线粒体分裂，并降低线粒体膜电位。CuCl 增加了 OECM-1 细胞的耗氧率和细胞外酸化率，但 DSF-Cu 则降低了这些速率。CuCl 在 OECM-1 细胞中稳定了低氧诱导因子 1α（HIF-1α）的表达，而与 DSF 结合则增强了该作用。DSF-Cu/Cu 处理的 OECM-1 细胞中 c-Myc 蛋白及其 Tyr58 和 Ser62 位点的磷酸化水平增加，而 N 端截断形式（Myc-nick）的水平降低。这些作用都被 ROS 清除剂 NAC 预处理所抑制。c-Myc 的过表达未能诱导 HIF-1α 的表达。这些发现为将 DSF-CuCl 复合物作为口腔鳞状细胞癌（OSCC）癌症治疗的再利用药物提供了新的见解。
