title: Q39, a novel synthetic Quinoxaline 1,4-Di-N-oxide compound with anti-cancer activity in hypoxia.
abstract: Hypoxia is one of the inevitable circumstances in various tumors and results in tumor resistance to radiotherapy and chemotherapy. The present data showed that 3-(4-bromophenyl)-2-(ethylsulfonyl)-6-methylquinoxaline 1,4-dioxide (Q39), derived from Quinoxaline 1,4-Di-N-oxide, possessed high anti-cancer activity in hypoxia. Cytotoxicity assay demonstrated that Q39 is a potential and high efficient anti-cancer compound in all tested cell lines with IC50 values of 0.18+/-0.03-8.88+/-1.12 microM in hypoxia and 0.33+/-0.04-8.74+/-1.28 microM in normoxia . In the following work concerning the mechanism of Q39 in hypoxia, we confirmed that Q39 could cause the apoptosis of K562 cells in a time-dependent manner. By fluorescence stain assay, Q39-induced mitochondria membrane potential (Delta Psi m) loss was observed in K562 cells in hypoxia. Based on the western blotting, Q39 decreased the protein expression of hypoxia-inducible factor-1alpha (HIF-1alpha) and vascular endothelial growth factor (VEGF) in hypoxia. The compound caused the activation of caspase-3 and subsequent cleavage of its substrate poly (ADP-ribose) polymerase (PARP) in hypoxia. Meanwhile, we found the upregulation of Bax by Q39 in K562 cells as well as the downregulation of Bcl-2. Q39 also influenced the expression of Mitogen-Activated Protein Kinase (MAPKs) and other proteins relative to mitochondria induced apoptosis. In addition, Q39-mediated apoptosis was not reversed after treatment with the JNK-specific inhibitor. In summary, the present study demonstrated Q39 was a novel compound against cancer cells in hypoxia. The mitochondrial pathway mediated by Bcl-2 protein family and MAPKs and the HIF-1 pathway might be involved in signaling Q39-induced apoptosis.
authors.affiliation: Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Qinjie
authors.initials: Q
authors.lastname: Weng
authors.forename: Duoduo
authors.initials: D
authors.lastname: Wang
authors.forename: Peng
authors.initials: P
authors.lastname: Guo
authors.forename: Liang
authors.initials: L
authors.lastname: Fang
authors.forename: Yongzhou
authors.initials: Y
authors.lastname: Hu
authors.forename: Qiaojun
authors.initials: Q
authors.lastname: He
authors.forename: Bo
authors.initials: B
authors.lastname: Yang
mesh_terms: D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D053148:Caspase 3 / Q000187:drug effects / Q000378:metabolism; D015687:Cell Hypoxia / Q000187:drug effects; D045744:Cell Line, Tumor; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000187:drug effects / Q000378:metabolism; D020128:Inhibitory Concentration 50; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D020928:Mitogen-Activated Protein Kinases / Q000187:drug effects / Q000378:metabolism; D011065:Poly(ADP-ribose) Polymerases / Q000187:drug effects / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000187:drug effects* / Q000378:metabolism; D011810:Quinoxalines / Q000008:administration & dosage / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D013997:Time Factors; D042461:Vascular Endothelial Growth Factor A / Q000187:drug effects / Q000378:metabolism
chemical_list: C528740:3-(4-bromophenyl)-2-(ethylsulfonyl)-6-methylquinoxaline-1,4-dioxide; D000970:Antineoplastic Agents; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D019253:Proto-Oncogene Proteins c-bcl-2; D011810:Quinoxalines; D042461:Vascular Endothelial Growth Factor A; D011065:Poly(ADP-ribose) Polymerases; D020928:Mitogen-Activated Protein Kinases; D053148:Caspase 3