Twigger, K, Roulstone, V, Kyula, J et al. (14 more authors) (2012) Reovirus exerts potent oncolytic effects in head and neck cancer cell lines that are independent of signalling in the EGFR pathway. BMC Cancer, 12. 368. ISSN 1471-2407
Abstract
Background: reovirus exploits aberrant signalling downstream of Ras to mediate tumor-specific oncolysis. Since ~90% squamous cell carcinomas of the head and neck (SCCHN) over-express EGFR and SCCHN cell lines are sensitive to oncolytic reovirus, we conducted a detailed analysis of the effects of reovirus in 15 head and neck cancer cell lines. Both pre- and post-entry events were studied in an attempt to define biomarkers predictive of sensitivity/resistance to reovirus. In particular, we analysed the role of EGFR/Ras signalling in determining virus-mediated cytotoxicity in SCCHN. Methods: to test whether EGFR pathway activity was predictive of increased sensitivity to reovirus, correlative analyses between reoviral IC50 by MTT assay and EGFR levels by western blot and FACS were conducted. Inhibition or stimulation of EGFR signalling were analysed for their effect on reoviral oncolysis by MTT assay, and viral growth by TCID50 assay. We next analysed the effects of inhibiting signalling downstream of Ras, by specific inhibitors of p38MAPK, PI3-K or MEK, on reoviral killing examined by MTT assay. The role of PKR in reoviral killing was also determined by blockade of PKR using 2-aminopurine and assaying for cell survival by MTT assay. The apoptotic response of SCCHN to reovirus was examined by western blot analysis of caspase 3 cleavage. Results: correlative analyses between reoviral sensitivity and EGFR levels revealed no association. Intermediate sub-viral and core particles showed the same infectivity/cytotoxicity as intact reovirus. Therefore, sensitivity was not determined by cell entry. In 4 cell lines, oncolysis and viral growth were both unaffected by inhibition or stimulation of EGFR signalling. Inhibition of signalling downstream of Ras did not abrogate reoviral oncolysis and, in addition, modulation of PKR using 2-aminopurine did not alter reovirus sensitivity in resistant cell lines. Caspase 3 cleavage was not detected in infected cells and oncolysis was observed in pan-caspase inhibited cells. Conclusions: in summary, reovirus is potently oncolytic in a broad panel of SCCHN cell lines. Attempts to define sensitivity/resistance by analysis of the EGFR/Ras/MAPK pathway have failed to provide a clear predictive biomarker of response. Further analysis of material from in vitro and clinical studies is ongoing in an attempt to shed further light on this issue.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2012, Twigger et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
Keywords: | Biomarker; Cancer; EGFR; Ras; Reovirus; Oncolytic virus |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Medicine and Health (Leeds) > School of Medicine (Leeds) > Leeds Institute of Cancer and Pathology (LICAP) > Clinical Cancer Research (Leeds) The University of Leeds > Faculty of Medicine and Health (Leeds) > School of Medicine (Leeds) > Leeds Institute of Cancer and Pathology (LICAP) > Oncology and Cancer Research - Labs (Leeds) The University of Leeds > Faculty of Medicine and Health (Leeds) > Institute of Molecular Medicine (LIMM) (Leeds) > Section of Oncology and Clinical Research (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 12 Aug 2016 09:31 |
Last Modified: | 01 Mar 2019 11:49 |
Published Version: | http://dx.doi.org/10.1186/1471-2407-12-368 |
Status: | Published |
Publisher: | BioMed Central |
Identification Number: | 10.1186/1471-2407-12-368 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:87598 |