title: Induction of glutathione-dependent DNA double-strand breaks by the novel anticancer drug brostallicin.
abstract: Brostallicin is a DNA minor groove binder in phase II clinical trials. Here, we show that brostallicin induces gamma-H2AX nuclear foci that colocalize with 53BP1 and are dependent on glutathione, as shown by inhibition of those gamma-H2AX foci by l-buthionine sulfoximine. To differentiate brostallicin from the clinically approved minor groove binder trabectedin (ecteinascidin 743), we tested whether the brostallicin-induced gamma-H2AX and antiproliferative responses were dependent on nucleotide excision repair and found that, unlike trabectedin, they are not. Additionally, brostallicin retained activity in the trabectedin-resistant HCT116-ER5 cell line. Induction of gamma-H2AX foci by brostallicin was partially dependent on the repair nuclease Mre11. Pretreatment with aphidicolin partially reduced brostallicin-induced gamma-H2AX foci, suggesting that brostallicin induces both replication-associated and replication-independent DNA damage. Replication-associated DNA damage was further shown by the colocalization of gamma-H2AX foci with replication foci and by the rapid inhibition of DNA synthesis and accumulation of cells in S phase in response to brostallicin. In addition, brostallicin was able to induce lower intensity gamma-H2AX foci in human circulating lymphocytes. Together, our results indicate that brostallicin induces DNA double-strand breaks and suggest gamma-H2AX as a pharmacodynamic biomarker for brostallicin.
authors: Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892-4255, USA.
authors: Josée
authors: J
authors: Guirouilh-Barbat
authors: Yong-Wei
authors: YW
authors: Zhang
authors: Yves
authors: Y
authors: Pommier
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D018906:Antineoplastic Agents, Alkylating / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D002453:Cell Cycle / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002868:Chromosomal Proteins, Non-Histone; D053903:DNA Breaks, Double-Stranded / Q000187:drug effects*; D004261:DNA Replication / Q000187:drug effects; D004268:DNA-Binding Proteins / Q000378:metabolism; D004149:Dioxoles / Q000494:pharmacology; D005978:Glutathione / Q000378:metabolism*; D006146:Guanidines / Q000494:pharmacology*; D045325:HCT116 Cells; D006657:Histones / Q000378:metabolism*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D000076228:MRE11 Homologue Protein; D010750:Phosphoproteins / Q000494:pharmacology; D011758:Pyrroles / Q000494:pharmacology*; D044005:Tetrahydroisoquinolines / Q000494:pharmacology; D000077606:Trabectedin; D000071857:Tumor Suppressor p53-Binding Protein 1
chemical_list: D000970:Antineoplastic Agents; D018906:Antineoplastic Agents, Alkylating; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D004149:Dioxoles; D006146:Guanidines; C468783:H2AX protein, human; D006657:Histones; D047908:Intracellular Signaling Peptides and Proteins; C121766:MRE11 protein, human; D010750:Phosphoproteins; D011758:Pyrroles; D044005:Tetrahydroisoquinolines; C498302:Trp53bp1 protein, mouse; D000071857:Tumor Suppressor p53-Binding Protein 1; D000076228:MRE11 Homologue Protein; D005978:Glutathione; D000077606:Trabectedin; C455279:brostallicin