Inhibition of the inflammatory cytokine TNF-α increases adenovirus activity in ovarian cancer via modulation of cIAP1/2 expression

Salako, M.A., Kulbe, H., Ingemarsdotter, C.K., Pirlo, K.J., Williams, S.L., Lockley, M., Balkwill, F.R. and McNeish, I.A. (2011) Inhibition of the inflammatory cytokine TNF-α increases adenovirus activity in ovarian cancer via modulation of cIAP1/2 expression. Molecular Therapy, 19(3), pp. 490-499. (doi: 10.1038/mt.2010.247)

Abstract

Oncolytic adenoviruses show promise as a cancer treatment. However, they generate acute inflammatory responses with production of cytokines, including tumor necrosis factor-α (TNF-α). We investigated whether inhibition of TNF-α augments efficacy of the E1A CR2-deleted adenovirus dl922-947 in ovarian cancer. dl922-947 induced transcription of TNF-α and its downstream signaling targets interleukin-6 and -8 (IL-6 and IL-8) in ovarian cancer cells. In vitro, RNAi-mediated knockdown of TNF-α reduced production of multiple inflammatory cytokines after infection and increased ovarian cancer cell sensitivity to virus cytotoxicity, as did treatment with the anti-TNF-α antibody infliximab. In vivo, stable knockdown of TNF-α in IGROV-1 xenografts increased the anticancer activity of dl922-947. In addition, inhibition of TNF-α using monoclonal antibodies also improved dl922-947 efficacy. This increased efficacy resulted from suppression of cellular inhibitor of apoptosis-1 and -2 (cIAP1 and cIAP2) transcription in malignant cells and a consequent increase in caspase-mediated apoptosis. These findings suggest that TNF-α acts as a survival factor in adenovirus-infected cells. Combining TNF-α inhibition with oncolytic adenoviruses could improve antitumor activity in clinical trials.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Mcneish, Professor Iain
• Authors: Salako, M.A., Kulbe, H., Ingemarsdotter, C.K., Pirlo, K.J., Williams, S.L., Lockley, M., Balkwill, F.R., and McNeish, I.A.
• College/School: College of Medical Veterinary and Life Sciences > School of Cancer Sciences
• Journal Name: Molecular Therapy
• ISSN: 1525-0016
• ISSN (Online): 1525-0024