title: Proapoptotic compound ARC targets Akt and N-myc in neuroblastoma cells.
abstract: We have previously described the identification of a nucleoside analog transcriptional inhibitor ARC (4-amino-6-hydrazino-7-beta-D-ribofuranosyl-7H-pyrrolo[2,3-d]-pyrimidine-5-carboxamide) that was able to induce apoptosis in cancer cell lines of different origin. Here, we report the characterization of ARC on a panel of neuroblastoma cell lines. We found that these cell lines were more than 10-fold sensitive to ARC than to the well-known nucleoside analog DRB (5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole), and that ARC-induced apoptosis proceeds through mitochondrial injury. Also, we observed that ARC-mediated cell death was accompanied by caspase-3 cleavage and repression of antiapoptotic proteins such as Mcl-1 and survivin. Conversely, we found that overexpression of Mcl-1-protected neuroblastoma cell line NB-1691 from ARC-induced apoptosis. Furthermore, we found that while ARC inhibited the phosphorylation of Akt Ser-473 in multiple cancer cell lines, forced expression of myristoylated Akt promoted resistance to ARC-induced apoptosis in neuroblastoma cells. In addition, we observed that ARC was able to downregulate the protein levels of N-myc, a commonly amplified oncogene in neuroblastomas, and Akt protected N-myc from ARC-induced downregulation. These data suggest that ARC may antagonize different antiapoptotic pathways and induce apoptosis in neuroblastoma cells via multiple mechanisms. Overall, ARC could represent an attractive candidate for anticancer drug development against neuroblastomas.
authors.affiliation: Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA.
authors.forename: S K
authors.initials: SK
authors.lastname: Radhakrishnan
authors.forename: M
authors.initials: M
authors.lastname: Halasi
authors.forename: U G
authors.initials: UG
authors.lastname: Bhat
authors.forename: R T
authors.initials: RT
authors.lastname: Kurmasheva
authors.forename: P J
authors.initials: PJ
authors.lastname: Houghton
authors.forename: A L
authors.initials: AL
authors.lastname: Gartel
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D008928:Mitochondria / Q000187:drug effects; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D009363:Neoplasm Proteins / Q000378:metabolism; D009447:Neuroblastoma / Q000473:pathology*; D009705:Nucleosides / Q000494:pharmacology*; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000187:drug effects* / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D016271:Proto-Oncogene Proteins c-myc / Q000187:drug effects* / Q000378:metabolism; D011743:Pyrimidines / Q000494:pharmacology*; D000077022:Survivin; D014407:Tumor Cells, Cultured
chemical_list: C509961:4-amino-6-hydrazino-7-beta-D-ribofuranosyl-7H-pyrrolo(2,3-d)-pyrimidine-5-carboxamide; D000970:Antineoplastic Agents; C107489:BIRC5 protein, human; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D009363:Neoplasm Proteins; D009705:Nucleosides; D019253:Proto-Oncogene Proteins c-bcl-2; D016271:Proto-Oncogene Proteins c-myc; D011743:Pyrimidines; D000077022:Survivin; D051057:Proto-Oncogene Proteins c-akt; D053148:Caspase 3