Peng-xing He1, Jie Zhang2, Yong-sheng Che3, Qiao-jun He1, Yi Chen2, Jian Ding2. 1. Institute of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China. 2. Division of Anti-tumor Pharmacology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China. 3. Beijing Institute of Pharmacology & Toxicology, Beijing 100190, China.
Abstract
AIM: G226 is a novel derivative of epipolythiodioxopiperazines with potent inhibitory activity against cancer cells. Here, we sought to identify potential targets involved in the anti-cancer activity of G226. METHODS: Cell proliferation assay was conducted in a panel of 12 human cancer cell lines. The activities of topoisomerase I (Topo I) and Topo II were studied using supercoiled pBR322 DNA relaxation and kDNA decatenation assays. ROS production was assessed with probes DCFH-DA and H&E. Western blot analysis and flow cytometry were used to examine DNA damage, apoptosis and cell cycle changes. RESULTS: G226 displayed potent cytotoxicity in the 12 human cancer cell lines with a mean IC50 value of 92.7 nmol/L. This compound (1-100 μmol/L) selectively inhibited the activity of Topo II, and elevated the expression of phosphorylated-H2AX in a dose-dependent manner. In Topo II-deficient HL60/MX2 cells, however, G226-induced DNA damage, apoptosis and cytotoxicity were only partially reduced, suggesting that Topo II was not essential for the anti-tumor effects of G226. Furthermore, G226 (0.125-2 μmol/L) dose-dependently elevated the intracellular levels of H2O2 and in the cancer cells, and pretreatment with GSH, NAC or DTT not only blocked G226-induced intracellular accumulation of ROS, but also abrogated G226-mediated phosphorylation of H2AX, apoptosis and cytotoxicity. CONCLUSION: G226-mediated ROS production contributes to the anti-cancer activity of this compound.
AIM: G226 is a novel derivative of epipolythiodioxopiperazines with potent inhibitory activity against cancer cells. Here, we sought to identify potential targets involved in the anti-cancer activity of G226. METHODS: Cell proliferation assay was conducted in a panel of 12 humancancer cell lines. The activities of topoisomerase I (Topo I) and Topo II were studied using supercoiled pBR322 DNA relaxation and kDNA decatenation assays. ROS production was assessed with probes DCFH-DA and H&E. Western blot analysis and flow cytometry were used to examine DNA damage, apoptosis and cell cycle changes. RESULTS:G226 displayed potent cytotoxicity in the 12 humancancer cell lines with a mean IC50 value of 92.7 nmol/L. This compound (1-100 μmol/L) selectively inhibited the activity of Topo II, and elevated the expression of phosphorylated-H2AX in a dose-dependent manner. In Topo II-deficient HL60/MX2 cells, however, G226-induced DNA damage, apoptosis and cytotoxicity were only partially reduced, suggesting that Topo II was not essential for the anti-tumor effects of G226. Furthermore, G226 (0.125-2 μmol/L) dose-dependently elevated the intracellular levels of H2O2 and in the cancer cells, and pretreatment with GSH, NAC or DTT not only blocked G226-induced intracellular accumulation of ROS, but also abrogated G226-mediated phosphorylation of H2AX, apoptosis and cytotoxicity. CONCLUSION:G226-mediated ROS production contributes to the anti-cancer activity of this compound.
Authors: Tyler Maser; Maria Rich; David Hayes; Ping Zhao; Abhinav B Nagulapally; Jeffrey Bond; Giselle Saulnier Sholler Journal: Cancer Med Date: 2017-04-21 Impact factor: 4.452
Authors: Dan Zhang; Bo Zhang; Li-Xin Zhou; Jun Zhao; You-You Yan; Yang-Ling Li; Jian-Mei Zeng; Lin-Ling Wang; Bo Yang; Neng-Ming Lin Journal: Acta Pharmacol Sin Date: 2016-09-26 Impact factor: 6.150