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Functional antibodies produced by oncolytic clostridia. Biochem Biophys Res Commun 2007; 364:985-9. [PMID: 17971292 DOI: 10.1016/j.bbrc.2007.10.126] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2007] [Accepted: 10/18/2007] [Indexed: 11/23/2022]
Abstract
Hypoxia is a hallmark of solid cancer and characterized by regions of low oxygen and necrosis due to insufficient blood perfusion. Intratumoral hypoxia triggers the transcription of genes responsible for cell survival. The transcription factor hypoxia-inducible factor 1alpha (HIF-1alpha) is a key regulator of this response. HIF activation is associated with resistance to radio- and chemotherapy and poor clinical outcome, and may therefore provide an attractive therapeutic target. Clostridium-based oncolysis is a promising therapeutic strategy for the treatment of hypoxic tumors where these microorganisms naturally home. Here, we report for the first time the isolation of transconjugants of two excellent tumor colonizing Clostridium strains, C. novyi-NT and C. sporogenes, expressing single chain antibodies specific for human HIF-1alpha. This is a first step towards Clostridium-directed antibody therapy (CDAT) that holds promise as a carrier of cancer therapeutics targeting the most resistant regions in human solid cancer.
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Abstract
Hypoxia is an integral characteristic of the tumor microenvironment, primarily due to the microvascular defects that accompany the accelerated neoplastic growth. The presence of tumor hypoxic areas correlates with negative outcome after radiotherapy, chemotherapy, and surgery, as hypoxia not only provides an environment directly facilitating chemo- and radio-resistance, but also encourages the evolution of phenotypic changes inducing permanent resistance to treatment and metastatic spread. Therefore, successful treatment of hypoxic cells has the potential to not only improve local control but also impact overall patient survival. Specific and selective targeting of hypoxic tumor areas can be achieved at all three steps of a gene therapy treatment: delivery of the therapeutic gene to the tumor, regulation of gene expression, and therapeutic efficacy. In this review the latest developments and innovations in hypoxia-targeted gene therapy are discussed. In particular, approaches such as hypoxia-conditionally replicating viruses, cellular vehicles, and gene therapy means to disrupt the hypoxia-inducible factor (HIF) signaling are outlined.
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Affiliation(s)
- Olga Greco
- Tumour Microcirculation Group, University of Sheffield, Royal Hallamshire Hospital, Sheffield, United Kingdom
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Theys J, Pennington O, Dubois L, Anlezark G, Vaughan T, Mengesha A, Landuyt W, Anné J, Burke PJ, Dûrre P, Wouters BG, Minton NP, Lambin P. Repeated cycles of Clostridium-directed enzyme prodrug therapy result in sustained antitumour effects in vivo. Br J Cancer 2006; 95:1212-9. [PMID: 17024128 PMCID: PMC2360559 DOI: 10.1038/sj.bjc.6603367] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The unique properties of the tumour microenvironment can be exploited by using recombinant anaerobic clostridial spores as highly selective gene delivery vectors. Although several recombinant Clostridium species have been generated during the past decade, their efficacy has been limited. Our goal was to substantially improve the prospects of clostridia as a gene delivery vector. Therefore, we have assessed a series of nitroreductase (NTR) enzymes for their capacity to convert the innocuous CB1954 prodrug to its toxic derivative. Among the enzymes tested, one showed superior prodrug turnover characteristics. In addition, we established an efficient gene transfer procedure, based on conjugation, which allows for the first time genetic engineering of Clostridium strains with superior tumour colonisation properties with high success rates. This conjugation procedure was subsequently used to create a recombinant C. sporogenes overexpressing the isolated NTR enzyme. Finally, analogous to a clinical setting situation, we have tested the effect of multiple consecutive treatment cycles, with antibiotic bacterial clearance between cycles. Importantly, this regimen demonstrated that intravenously administered spores of NTR-recombinant C. sporogenes produced significant antitumour efficacy when combined with prodrug administration.
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Affiliation(s)
- J Theys
- Department of Radiation Oncology (Maastro Lab), GROW Research Institute, University of Maastricht, UNS 50/23, PO Box 616, Maastricht 6200 MD, The Netherlands
| | - O Pennington
- Institute of Infection, Immunity and Inflammation, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - L Dubois
- Department of Radiation Oncology (Maastro Lab), GROW Research Institute, University of Maastricht, UNS 50/23, PO Box 616, Maastricht 6200 MD, The Netherlands
| | - G Anlezark
- Centre for Applied Microbiology and Research, Porton Down, Salisbury SP4 0JG, UK
| | - T Vaughan
- Centre for Applied Microbiology and Research, Porton Down, Salisbury SP4 0JG, UK
| | - A Mengesha
- Department of Radiation Oncology (Maastro Lab), GROW Research Institute, University of Maastricht, UNS 50/23, PO Box 616, Maastricht 6200 MD, The Netherlands
| | - W Landuyt
- Experimental Radiobiology/LEO, Gasthuisberg-CDG, Herestraat 49, Leuven 3000, Belgium
| | - J Anné
- Laboratory of Bacteriology, Rega Institute, KU Leuven, Minderbroedersstraat 10, Leuven 3000, Belgium
| | - P J Burke
- Enact Pharma, Porton Down Science Park, Salisbury SP4 0JG, UK
| | - P Dûrre
- Mikrobiologie und Biotechnologie, University Ulm, Ulm 89069, Germany
| | - B G Wouters
- Department of Radiation Oncology (Maastro Lab), GROW Research Institute, University of Maastricht, UNS 50/23, PO Box 616, Maastricht 6200 MD, The Netherlands
| | - N P Minton
- Institute of Infection, Immunity and Inflammation, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - P Lambin
- Department of Radiation Oncology (Maastro Lab), GROW Research Institute, University of Maastricht, UNS 50/23, PO Box 616, Maastricht 6200 MD, The Netherlands
- E-mail:
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Abstract
Hypoxic/necrotic regions, absent in normal tissues, can be exploited to target tumours in cancer therapy using nonpathogenic strains of the bacterial genus Clostridium. Following administration of Clostridium spores to tumour-bearing organisms, these spores can only germinate within the hypoxic/necrotic regions of solid tumours, proving their exquisite selectivity. Low oxygen tension is a common feature of solid tumours, which may arise from the unique physiological environment, generated to a large extent by the abnormal tumour vasculature, and provides as such a niche for anaerobic bacteria. Some clostridia tested clearly showed innate oncolytic activity, but they could not completely eradicate the tumour. Recombinant clostridia producing prodrug-converting enzymes or cytokines resulted in the production of such proteins solely within the tumour, and where applicable, could convert the prodrug in a toxic compound. Moreover, in some cases, tumour eradication or tumour control could be observed. This review brings an overview of the relative successes and failures of the Clostridium-directed tumour therapy with both wild-type strains and strains producing proteins useful in antitumour therapy.
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Affiliation(s)
- S Barbé
- Laboratory of Bacteriology, Rega Institute for Medical Research, K.U. Leuven, Leuven, Belgium
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55
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Van Mellaert L, Barbé S, Anné J. Clostridium spores as anti-tumour agents. Trends Microbiol 2006; 14:190-6. [PMID: 16500103 DOI: 10.1016/j.tim.2006.02.002] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2005] [Revised: 01/27/2006] [Accepted: 02/10/2006] [Indexed: 01/23/2023]
Abstract
The successful treatment of cancer remains a huge challenge. Consequently, efforts are being made to develop alternative methods of tumour therapy. One of these is the use of live Clostridium species, based on the observation that obligatory anaerobic bacteria specifically colonize the hypoxic and necrotic regions that are present in solid tumours but normally absent in other parts of the body. Although past results have fuelled scepticism about its clinical use, recent promising findings emphasize the potential of Clostridium-directed tumour therapy. These recent developments are reviewed and the reintroduction of this tumour-targeting protein delivery system into clinical settings is discussed.
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Affiliation(s)
- Lieve Van Mellaert
- Rega Institute for Medical Research, Minderbroedersstraat 10, B-3000 Leuven, Belgium
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