XI-006 induces potent p53-independent apoptosis in Ewing sarcoma

Kathleen I Pishas; Alaknanda Adwal; Susan J Neuhaus; Mark T Clayer; Gelareh Farshid; Alexander H Staudacher; David F Callen

doi:10.1038/srep11465

XI-006 induces potent p53-independent apoptosis in Ewing sarcoma

Sci Rep. 2015 Jun 22:5:11465. doi: 10.1038/srep11465.

Authors

Kathleen I Pishas^{1

2}, Alaknanda Adwal², Susan J Neuhaus³, Mark T Clayer⁴, Gelareh Farshid⁵, Alexander H Staudacher^{6

7}, David F Callen^{1

2}

Affiliations

¹ Sarcoma Research Group, Discipline of Medicine, University of Adelaide, Adelaide, Australia.
² Cancer Therapeutics Laboratory, Discipline of Medicine, University of Adelaide, Adelaide, Australia.
³ Department of Surgery, Royal Adelaide Hospital and University of Adelaide, Adelaide, Australia.
⁴ Department of Orthopaedics and Trauma, Royal Adelaide Hospital, Adelaide, Australia.
⁵ Division of Tissue Pathology, SA Pathology, Adelaide, Australia.
⁶ Translational Oncology Laboratory, Centre for Cancer Biology, SA Pathology, Adelaide, Australia.
⁷ School of Medicine, University of Adelaide, Adelaide, Australia.

Abstract

There is an imperious need for the development of novel therapeutics for the treatment of Ewing sarcoma, the second most prevalent solid bone tumour observed in children and young adolescents. Recently, a 4-nitrobenzofuroxan derivative, XI-006 (NSC207895) was shown to diminish MDM4 promoter activity in breast cancer cell lines. As amplification of MDM4 is frequently observed in sarcomas, this study examined the therapeutic potential of XI-006 for the treatment of Ewing and osteosarcoma. XI-006 treatment of Ewing and osteosarcoma cell lines (n = 11) resulted in rapid and potent apoptosis at low micro-molar concentrations specifically in Ewing sarcoma cell lines (48 hr IC50 0.099-1.61 μM). Unexpectedly, apoptotic response was not dependent on MDM4 mRNA/protein levels or TP53 status. Alkaline/neutral comet and γH2AX immunofluorescence assays revealed that the cytotoxic effects of XI-006 could not be attributed to the induction of DNA damage. RNA expression analysis revealed that the mechanism of action of XI-006 could be accredited to the inhibition of cell division and cycle regulators such as KIF20A and GPSM2. Finally, potent synergy between XI-006 and olaparib (PARP inhibitor) were observed due to the down-regulation of Mre11. Our findings suggest that XI-006 represents a novel therapeutic intervention for the treatment of Ewing sarcoma.

MeSH terms

Antineoplastic Agents / pharmacology*
Apoptosis / drug effects*
Bone Neoplasms / drug therapy*
Calcium-Binding Proteins
Carrier Proteins / biosynthesis
Cell Adhesion Molecules
Cell Cycle Proteins
Cell Division / drug effects
Cell Line, Tumor
Cyclic N-Oxides / chemistry
DNA Damage / genetics
DNA-Binding Proteins / biosynthesis
Histones / metabolism
Humans
Intracellular Signaling Peptides and Proteins / antagonists & inhibitors
Kinesins / antagonists & inhibitors
MRE11 Homologue Protein
Membrane Proteins / biosynthesis
Nuclear Proteins / biosynthesis
Nuclear Proteins / genetics
Oxadiazoles / pharmacology*
Phthalazines / pharmacology
Piperazines / pharmacology*
Promoter Regions, Genetic / drug effects*
Proto-Oncogene Proteins / biosynthesis
Proto-Oncogene Proteins / genetics
Sarcoma, Ewing / drug therapy*
Tumor Suppressor Protein p53 / metabolism
Utrophin / biosynthesis

Substances

4-nitrobenzodifuroxan
Antineoplastic Agents
Calcium-Binding Proteins
Carrier Proteins
Cell Adhesion Molecules
Cell Cycle Proteins
Cyclic N-Oxides
DNA-Binding Proteins
EDIL3 protein, human
GPSM2 protein, human
H2AX protein, human
HEG1 protein, human
Histones
Intracellular Signaling Peptides and Proteins
KIF20A protein, human
MDM4 protein, human
MRE11 protein, human
Membrane Proteins
Nuclear Proteins
Oxadiazoles
Phthalazines
Piperazines
Proto-Oncogene Proteins
Tumor Suppressor Protein p53
UTRN protein, human
Utrophin
XI-006
flotillins
MRE11 Homologue Protein
Kinesins
olaparib