Investigational New Drugs

, Volume 34, Issue 5, pp 663–676 | Cite as

Involvement of AMP-activated protein kinase in mediating pyrrolo-1,5-benzoxazepine–induced apoptosis in neuroblastoma cells

  • Jennifer C. Lennon
  • Stefania Butini
  • Giuseppe Campiani
  • Anne O’Meara
  • D. Clive Williams
  • Daniela M. Zisterer


Neuroblastoma, a paediatric malignancy of the sympathetic nervous system, accounts for 15 % of childhood cancer deaths. Despite advances in understanding the biology, it remains one of the most difficult paediatric cancers to treat partly due to the development of multidrug resistance. There is thus a compelling demand for new treatment strategies that can bypass resistance mechanisms. The pyrrolo-1,5-benzoxazepine (PBOX) compounds are a series of novel microtubule-targeting agents that potently induce apoptosis in various tumour models. We have previously reported that PBOX compounds induce apoptosis in drug sensitive and multidrug resistant neuroblastoma cells and synergistically enhance apoptosis induced by chemotherapeutics such as carboplatin. In this study we present further data concerning the molecular basis of PBOX-induced apoptosis in neuroblastoma. We demonstrate that PBOX-6 induced AMP-activated protein kinase (AMPK) activation and downstream acetyl-CoA carboxylase phosphorylation. Increased reactive oxygen species (ROS) appeared to serve as the upstream signal for AMPK activation as pretreatment of cells with the antioxidant N-acetylcysteine inhibited both AMPK activation and PBOX-induced apoptosis. Furthermore, activation of AMPK by PBOX-6 was found to inhibit mTOR complex 1 (mTORC1) signalling. Finally, we demonstrate the efficacy of PBOX-6 in an in vivo xenograft model of neuroblastoma. This study provides new insights into understanding the molecular and cellular mechanisms involved in PBOX-induced cell death in neuroblastoma and further supports their future use as novel anti-cancer agents for the treatment of neuroblastoma.





Acetyl Co-A carboxylase


5’ adenosine monophosphate-activated protein kinase


Chronic myeloid leukaemia




Eukaryotic elongation factor 2


Fluorescence associated cell sorter


Foetal bovine serum


Hydrogen peroxide


Myeloid cell leukemia 1


Multidrug resistance


Microtubule targeting agent


Mammalian target of rapamycin




Reactive oxygen species


Poly (ADP-ribose) polymerase


Phosphate buffered saline





Stefania Butini would like to thank Istituto Toscano Tumori. This study was funded by the National Children’s Research Centre, Our Lady’s Children’s Hospital, Crumlin, Dublin, Ireland.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.


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Copyright information

© Springer Science+Business Media New York 2016

Authors and Affiliations

  • Jennifer C. Lennon
    • 1
    • 2
  • Stefania Butini
    • 3
  • Giuseppe Campiani
    • 3
  • Anne O’Meara
    • 4
  • D. Clive Williams
    • 1
  • Daniela M. Zisterer
    • 1
  1. 1.School of Biochemistry and Immunology, Trinity Biomedical Sciences InstituteTrinity College DublinDublin 2Ireland
  2. 2.The National Children’s Research CentreDublinIreland
  3. 3.European Research Centre for Drug Discovery & Development (NatSynDrugs)University of SienaSienaItaly
  4. 4.Our Lady’s Children’s HospitalDublin 12Ireland

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