1
|
Lu SC, Barry MA. Locked and loaded: engineering and arming oncolytic adenoviruses to enhance anti-tumor immune responses. Expert Opin Biol Ther 2022; 22:1359-1378. [DOI: 10.1080/14712598.2022.2139601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
| | - Michael A Barry
- Division of Infectious Diseases, Department of Medicine
- Department of Immunology
- Department of Molecular Medicine, Mayo Clinic, Rochester, MN 55905, USA
| |
Collapse
|
2
|
Kontermann RE, Ungerechts G, Nettelbeck DM. Viro-antibody therapy: engineering oncolytic viruses for genetic delivery of diverse antibody-based biotherapeutics. MAbs 2021; 13:1982447. [PMID: 34747345 PMCID: PMC8583164 DOI: 10.1080/19420862.2021.1982447] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Cancer therapeutics approved for clinical application include oncolytic viruses and antibodies, which evolved by nature, but were improved by molecular engineering. Both facilitate outstanding tumor selectivity and pleiotropic activities, but also face challenges, such as tumor heterogeneity and limited tumor penetration. An innovative strategy to address these challenges combines both agents in a single, multitasking therapeutic, i.e., an oncolytic virus engineered to express therapeutic antibodies. Such viro-antibody therapies genetically deliver antibodies to tumors from amplified virus genomes, thereby complementing viral oncolysis with antibody-defined therapeutic action. Here, we review the strategies of viro-antibody therapy that have been pursued exploiting diverse virus platforms, antibody formats, and antibody-mediated modes of action. We provide a comprehensive overview of reported antibody-encoding oncolytic viruses and highlight the achievements of 13 years of viro-antibody research. It has been shown that functional therapeutic antibodies of different formats can be expressed in and released from cancer cells infected with different oncolytic viruses. Virus-encoded antibodies have implemented direct tumor cell killing, anti-angiogenesis, or activation of adaptive immune responses to kill tumor cells, tumor stroma cells or inhibitory immune cells. Importantly, numerous reports have shown therapeutic activity complementary to viral oncolysis for these modalities. Also, challenges for future research have been revealed. Established engineering technologies for both oncolytic viruses and antibodies will enable researchers to address these challenges, facilitating the development of effective viro-antibody therapeutics.
Collapse
Affiliation(s)
- Roland E Kontermann
- Institute of Cell Biology and Immunology, University of Stuttgart, Stuttgart, Germany.,Stuttgart Research Center Systems Biology, University of Stuttgart, Stuttgart, Germany
| | - Guy Ungerechts
- Clinical Cooperation Unit Virotherapy, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Department of Medical Oncology, National Center for Tumor Diseases (NCT) and University Hospital Heidelberg, Heidelberg, Germany.,Cancer Therapeutics Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Dirk M Nettelbeck
- Clinical Cooperation Unit Virotherapy, German Cancer Research Center (DKFZ), Heidelberg, Germany
| |
Collapse
|
3
|
Hyaluronidase expression within tumors increases virotherapy efficacy and T cell accumulation. MOLECULAR THERAPY-ONCOLYTICS 2021; 22:27-35. [PMID: 34377767 PMCID: PMC8321894 DOI: 10.1016/j.omto.2021.05.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 05/19/2021] [Indexed: 12/28/2022]
Abstract
Oncolytic viruses (OVs) preferentially infect and selectively replicate in cancer cells. OVs have been tested in clinical trials as monotherapy or in combination with chemotherapy, radiotherapy, and immunotherapy. However, the dense extracellular matrix hampers the intratumoral spreading and efficacy of OVs. Previously we described VCN-01, an oncolytic adenovirus expressing a soluble version of human sperm hyaluronidase (hyal) PH20, which exhibited enhanced intratumoral distribution and antitumor activity in different models. Here, we present two oncolytic adenoviruses designed to increase the secretion of PH20 compared to VCN-01. ICO15K-40SAPH20, encoding PH20 under an Ad40 splice acceptor, and ICO15K-E1aPH20 expressing PH20 fused to the E1A gene by P2A peptide. We demonstrate that increased hyal activity improves antitumor efficacy in both a sensitive immunodeficient model and an immunocompetent model. Moreover, we show that hyal activity impacts T cell accumulation in tumors, highlighting the value of a hyaluronidase-expressing virus for combinations with other immunotherapies in cancers involving dense stroma.
Collapse
|
4
|
Xie S, Fan W, Yang C, Lei W, Pan H, Tong X, Wu Y, Wang S. Beclin1‑armed oncolytic Vaccinia virus enhances the therapeutic efficacy of R‑CHOP against lymphoma in vitro and in vivo. Oncol Rep 2021; 45:987-996. [PMID: 33469679 PMCID: PMC7860022 DOI: 10.3892/or.2021.7942] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 12/04/2020] [Indexed: 01/03/2023] Open
Abstract
Non-Hodgkin lymphoma (NHL) is a form of lymphoid malignancy, with diffuse large B cell lymphoma (DLBCL) being the most common NHL isoform. Approximately half of patients with DLBCL are successfully cured via first-line Rituximab, Cyclophosphamide, Epirubicin, Vindesine, Prednisolone (R-CHOP) treatment. However, 30–40% of patients with DLBCL ultimately suffer from treatment-refractory or relapsed disease. These patients often suffer from high mortality rates owing to a lack of suitable therapeutic options, and all patients are at a high risk of serious treatment-associated dose-dependent toxicity. As such, it is essential to develop novel treatments for NHL that are less toxic and more efficacious. Oncolytic Vaccinia virus (OVV) has shown promise as a means of treating numerous types of cancer. Gene therapy strategies further enhance OVV-based therapy by improving tumor cell recognition and immune evasion. Beclin1 is an autophagy-associated gene that, when upregulated, induces excess autophagy and cell death. The present study aimed to develop an OVV-Beclin1 therapy capable of inducing autophagic tumor cell death. OVV-Beclin1 was able to efficiently kill NHL cells and to increase the sensitivity of these cells to R-CHOP, thereby decreasing the dose-dependent toxic side effects associated with this chemotherapeutic regimen. The combination of OVV-Beclin1 and R-CHOP also significantly improved tumor growth inhibition and survival in a BALB/c murine model system owing to the synergistic induction of autophagic cell death. Together, these findings suggest that OVV-Beclin1 infection can induce significant autophagic cell death in NHL, highlighting this as a novel means of inducing tumor cell death via a mechanism that is distinct from apoptosis and necrosis.
Collapse
Affiliation(s)
- Shufang Xie
- The Second Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou 310000, P.R. China
| | - Weimin Fan
- Molecular Diagnosis Laboratory, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, Zhejiang 310014, P.R. China
| | - Chen Yang
- Molecular Diagnosis Laboratory, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, Zhejiang 310014, P.R. China
| | - Wen Lei
- Department of Hematology, The Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, P.R. China
| | - Hongying Pan
- Department of Infectious Diseases, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, Zhejiang 310014, P.R. China
| | - Xiangmin Tong
- Molecular Diagnosis Laboratory, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, Zhejiang 310014, P.R. China
| | - Yi Wu
- Department of Hematology, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, Zhejiang 310014, P.R. China
| | - Shibing Wang
- Molecular Diagnosis Laboratory, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, Zhejiang 310014, P.R. China
| |
Collapse
|
5
|
Farrera-Sal M, de Sostoa J, Nuñez-Manchón E, Moreno R, Fillat C, Bazan-Peregrino M, Alemany R. Arming Oncolytic Adenoviruses: Effect of Insertion Site and Splice Acceptor on Transgene Expression and Viral Fitness. Int J Mol Sci 2020; 21:E5158. [PMID: 32708234 PMCID: PMC7404292 DOI: 10.3390/ijms21145158] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 07/17/2020] [Accepted: 07/17/2020] [Indexed: 11/16/2022] Open
Abstract
Oncolytic adenoviruses (OAds) present limited efficacy in clinics. The insertion of therapeutic transgenes into OAds genomes, known as "arming OAds", has been the main strategy to improve their therapeutic potential. Different approaches were published in the decade of the 2000s, but with few comparisons. Most armed OAds have complete or partial E3 deletions, leading to a shorter half-life in vivo. We generated E3+ OAds using two insertion sites, After-fiber and After-E4, and two different splice acceptors linked to the major late promoter, either the Ad5 protein IIIa acceptor (IIIaSA) or the Ad40 long fiber acceptor (40SA). The highest transgene levels were obtained with the After-fiber location and 40SA. However, the set of codons of the transgene affected viral fitness, highlighting the relevance of transgene codon usage when arming OAds using the major late promoter.
Collapse
Affiliation(s)
- Martí Farrera-Sal
- ProCure Program, Institut Català d’Oncologia, and Oncobell Program IDIBELL, 08908 L’Hospitalet de Llobregat, Spain; (M.F.-S.); (J.d.S.); (R.M.)
- VCN Biosciences S.L., 08174 Sant Cugat, Spain;
| | - Jana de Sostoa
- ProCure Program, Institut Català d’Oncologia, and Oncobell Program IDIBELL, 08908 L’Hospitalet de Llobregat, Spain; (M.F.-S.); (J.d.S.); (R.M.)
| | - Estela Nuñez-Manchón
- Institut d’investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Universitat de Barcelona, 08036 Barcelona, Spain; (E.N.-M.); (C.F.)
| | - Rafael Moreno
- ProCure Program, Institut Català d’Oncologia, and Oncobell Program IDIBELL, 08908 L’Hospitalet de Llobregat, Spain; (M.F.-S.); (J.d.S.); (R.M.)
| | - Cristina Fillat
- Institut d’investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Universitat de Barcelona, 08036 Barcelona, Spain; (E.N.-M.); (C.F.)
| | | | - Ramon Alemany
- ProCure Program, Institut Català d’Oncologia, and Oncobell Program IDIBELL, 08908 L’Hospitalet de Llobregat, Spain; (M.F.-S.); (J.d.S.); (R.M.)
| |
Collapse
|
6
|
Effect of Transgene Location, Transcriptional Control Elements and Transgene Features in Armed Oncolytic Adenoviruses. Cancers (Basel) 2020; 12:cancers12041034. [PMID: 32340119 PMCID: PMC7226017 DOI: 10.3390/cancers12041034] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 04/17/2020] [Accepted: 04/21/2020] [Indexed: 12/15/2022] Open
Abstract
Clinical results with oncolytic adenoviruses (OAds) used as antitumor monotherapies show limited efficacy. To increase OAd potency, transgenes have been inserted into their genome, a strategy known as “arming OAds”. Here, we review different parameters that affect the outcome of armed OAds. Recombinant adenovirus used in gene therapy and vaccination have been the basis for the design of armed OAds. Hence, early region 1 (E1) and early region 3 (E3) have been the most commonly used transgene insertion sites, along with partially or complete E3 deletions. Besides transgene location and orientation, transcriptional control elements, transgene function, either virocentric or immunocentric, and even the codons encoding it, greatly impact on transgene levels and virus fitness.
Collapse
|
7
|
Ricordel M, Foloppe J, Pichon C, Findeli A, Tosch C, Cordier P, Cochin S, Quémeneur E, Camus-Bouclainville C, Bertagnoli S, Erbs P. Oncolytic properties of non-vaccinia poxviruses. Oncotarget 2018; 9:35891-35906. [PMID: 30542506 PMCID: PMC6267605 DOI: 10.18632/oncotarget.26288] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 10/24/2018] [Indexed: 01/13/2023] Open
Abstract
Vaccinia virus, a member of the Poxviridae family, has been extensively used as an oncolytic agent and has entered late stage clinical development. In this study, we evaluated the potential oncolytic properties of other members of the Poxviridae family. Numerous tumor cell lines were infected with ten non-vaccinia poxviruses to identify which virus displayed the most potential as an oncolytic agent. Cell viability indicated that tumor cell lines were differentially susceptible to each virus. Raccoonpox virus was the most potent of the tested poxviruses and was highly effective in controlling cell growth in all tumor cell lines. To investigate further the oncolytic capacity of the Raccoonpox virus, we have generated a thymidine kinase (TK)-deleted recombinant Raccoonpox virus expressing the suicide gene FCU1. This TK-deleted Raccoonpox virus was notably attenuated in normal primary cells but replicated efficiently in numerous tumor cell lines. In human colon cancer xenograft model, a single intratumoral inoculation of the recombinant Raccoonpox virus, in combination with 5-fluorocytosine administration, produced relevant tumor growth control. The results demonstrated significant antitumoral activity of this new modified Raccoonpox virus armed with FCU1 and this virus could be considered to be included into the growing armamentarium of oncolytic virotherapy for cancer.
Collapse
Affiliation(s)
- Marine Ricordel
- Transgene SA, Illkirch-Graffenstaden 67405, France.,Current address: Polyplus-transfection SA, Illkirch-Graffenstaden 67400, France
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Ungerechts G, Engeland CE, Buchholz CJ, Eberle J, Fechner H, Geletneky K, Holm PS, Kreppel F, Kühnel F, Lang KS, Leber MF, Marchini A, Moehler M, Mühlebach MD, Rommelaere J, Springfeld C, Lauer UM, Nettelbeck DM. Virotherapy Research in Germany: From Engineering to Translation. Hum Gene Ther 2018; 28:800-819. [PMID: 28870120 DOI: 10.1089/hum.2017.138] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Virotherapy is a unique modality for the treatment of cancer with oncolytic viruses (OVs) that selectively infect and lyse tumor cells, spread within tumors, and activate anti-tumor immunity. Various viruses are being developed as OVs preclinically and clinically, several of them engineered to encode therapeutic proteins for tumor-targeted gene therapy. Scientists and clinicians in German academia have made significant contributions to OV research and development, which are highlighted in this review paper. Innovative strategies for "shielding," entry or postentry targeting, and "arming" of OVs have been established, focusing on adenovirus, measles virus, parvovirus, and vaccinia virus platforms. Thereby, new-generation virotherapeutics have been derived. Moreover, immunotherapeutic properties of OVs and combination therapies with pharmacotherapy, radiotherapy, and especially immunotherapy have been investigated and optimized. German investigators are increasingly assessing their OV innovations in investigator-initiated and sponsored clinical trials. As a prototype, parvovirus has been tested as an OV from preclinical proof-of-concept up to first-in-human clinical studies. The approval of the first OV in the Western world, T-VEC (Imlygic), has further spurred the involvement of investigators in Germany in international multicenter studies. With the encouraging developments in funding, commercialization, and regulatory procedures, more German engineering will be translated into OV clinical trials in the near future.
Collapse
Affiliation(s)
- Guy Ungerechts
- 1 Department of Medical Oncology, National Center for Tumor Diseases and Heidelberg University Hospital , Heidelberg, Germany .,2 Department of Translational Oncology, National Center for Tumor Diseases and German Cancer Research Center (DKFZ), Heidelberg, Germany .,3 Centre for Innovative Cancer Research, Ottawa Hospital Research Institute , Ottawa, Ontario, Canada
| | - Christine E Engeland
- 1 Department of Medical Oncology, National Center for Tumor Diseases and Heidelberg University Hospital , Heidelberg, Germany .,2 Department of Translational Oncology, National Center for Tumor Diseases and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Christian J Buchholz
- 4 Molecular Biotechnology and Gene Therapy, Paul-Ehrlich-Institut , Langen, Germany .,5 German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), partner site Heidelberg, Germany
| | - Jürgen Eberle
- 6 Charité -Universitätsmedizin Berlin, Department of Dermatology, Skin Cancer Centre Charité , Berlin, Germany
| | - Henry Fechner
- 7 Technische Universität Berlin, Institute of Biotechnology , Department of Applied Biochemistry, Berlin, Germany
| | - Karsten Geletneky
- 8 Department of Neurosurgery, Klinikum Darmstadt , Darmstadt, Germany
| | - Per Sonne Holm
- 9 Department of Urology, Klinikum rechts der Isar, Technical University Munich , Munich, Germany
| | - Florian Kreppel
- 10 Chair of Biochemistry and Molecular Medicine, Center for Biomedical Research and Education (ZBAF), Faculty of Health, University Witten/Herdecke (UW/H), Witten, Germany
| | - Florian Kühnel
- 11 Department of Gastroenterology, Hepatology, and Endocrinology, Hannover Medical School (MHH), Hannover, Germany
| | - Karl Sebastian Lang
- 12 Institute of Immunology, Medical Faculty, University of Duisburg-Essen , Essen, Germany
| | - Mathias F Leber
- 1 Department of Medical Oncology, National Center for Tumor Diseases and Heidelberg University Hospital , Heidelberg, Germany .,2 Department of Translational Oncology, National Center for Tumor Diseases and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Antonio Marchini
- 13 Department of Tumor Virology, Infection, Inflammation and Cancer Program, German Cancer Research Center (DKFZ), Heidelberg, Germany .,14 Laboratory of Oncolytic Virus Immuno-Therapeutics (LOVIT), Luxembourg Institute of Health (LIH), Strassen, Luxembourg
| | - Markus Moehler
- 15 University Medical Center Mainz , I. Dept. of Internal Medicine, Mainz, Germany
| | - Michael D Mühlebach
- 16 Product Testing of Immunological Veterinary Medicinal Products, Paul-Ehrlich-Institut , Langen, Germany
| | - Jean Rommelaere
- 13 Department of Tumor Virology, Infection, Inflammation and Cancer Program, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Christoph Springfeld
- 1 Department of Medical Oncology, National Center for Tumor Diseases and Heidelberg University Hospital , Heidelberg, Germany
| | - Ulrich M Lauer
- 17 Department of Clinical Tumor Biology, Medical University Hospital , Tübingen, Germany .,18 German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), partner site Tübingen, Germany
| | | |
Collapse
|
9
|
Vaccinia Virus Shuffling: deVV5, a Novel Chimeric Poxvirus with Improved Oncolytic Potency. Cancers (Basel) 2018; 10:cancers10070231. [PMID: 29996551 PMCID: PMC6070928 DOI: 10.3390/cancers10070231] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 05/31/2018] [Accepted: 06/01/2018] [Indexed: 01/04/2023] Open
Abstract
Oncolytic virus (OV) therapy has emerged as a promising approach for cancer treatment with the potential to be less toxic and more efficient than classic cancer therapies. Various types of OVs in clinical development, including Vaccinia virus (VACV)-derived OVs, have shown good safety profiles, but limited therapeutic efficacy as monotherapy in some cancer models. Many different methods have been employed to improve the oncolytic potency of OVs. In this study, we used a directed evolution process, pooling different strains of VACV, including Copenhagen, Western Reserve and Wyeth strains and the attenuated modified vaccinia virus Ankara (MVA), to generate a new recombinant poxvirus with increased oncolytic properties. Through selective pressure, a chimeric VACV, deVV5, with increased cancer cell killing capacity and tumor selectivity in vitro was derived. The chimeric viral genome contains sequences of all parental strains. To further improve the tumor selectivity and anti-tumor activity of deVV5, we generated a thymidine kinase (TK)-deleted chimeric virus armed with the suicide gene FCU1. This TK-deleted virus, deVV5-fcu1 replicated efficiently in human tumor cells, and was notably attenuated in normal primary cells. These studies demonstrate the potential of directed evolution as an efficient way to generate recombinant poxviruses with increased oncolytic potency, and with high therapeutic index to improve cancer therapy.
Collapse
|
10
|
Ricordel M, Foloppe J, Pichon C, Sfrontato N, Antoine D, Tosch C, Cochin S, Cordier P, Quemeneur E, Camus-Bouclainville C, Bertagnoli S, Erbs P. Cowpox Virus: A New and Armed Oncolytic Poxvirus. MOLECULAR THERAPY-ONCOLYTICS 2017; 7:1-11. [PMID: 28951885 PMCID: PMC5607123 DOI: 10.1016/j.omto.2017.08.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 08/17/2017] [Indexed: 12/21/2022]
Abstract
Oncolytic virus therapy has recently been recognized as a promising new therapeutic approach for cancer treatment. In this study, we are proposing for the first time to evaluate the in vitro and in vivo oncolytic capacities of the Cowpox virus (CPXV). To improve the tumor selectivity and oncolytic activity, we developed a thymidine kinase (TK)-deleted CPXV expressing the suicide gene FCU1, which converts the non-toxic prodrug 5-fluorocytosine (5-FC) into cytotoxic 5-fluorouracil (5-FU) and 5-fluorouridine-5′-monophosphate (5-FUMP). This TK-deleted virus replicated efficiently in human tumor cell lines; however, it was notably attenuated in normal primary cells, thus displaying a good therapeutic index. Furthermore, this new recombinant poxvirus rendered cells sensitive to 5-FC. In vivo, after systemic injection in mice, the TK-deleted variant caused significantly less mortality than the wild-type strain. A biodistribution study demonstrated high tumor selectivity and low accumulation in normal tissues. In human xenograft models of solid tumors, the recombinant CPXV also displayed high replication, inducing relevant tumor growth inhibition. This anti-tumor effect was improved by 5-FC co-administration. These results demonstrated that CPXV is a promising oncolytic vector capable of expressing functional therapeutic transgenes.
Collapse
Affiliation(s)
- Marine Ricordel
- TRANSGENE S.A, 400 Boulevard Gonthier d'Andernach, 67400 Illkirch, France
| | - Johann Foloppe
- TRANSGENE S.A, 400 Boulevard Gonthier d'Andernach, 67400 Illkirch, France
| | - Christelle Pichon
- TRANSGENE S.A, 400 Boulevard Gonthier d'Andernach, 67400 Illkirch, France
| | - Nathalie Sfrontato
- TRANSGENE S.A, 400 Boulevard Gonthier d'Andernach, 67400 Illkirch, France
| | - Delphine Antoine
- TRANSGENE S.A, 400 Boulevard Gonthier d'Andernach, 67400 Illkirch, France
| | - Caroline Tosch
- TRANSGENE S.A, 400 Boulevard Gonthier d'Andernach, 67400 Illkirch, France
| | - Sandrine Cochin
- TRANSGENE S.A, 400 Boulevard Gonthier d'Andernach, 67400 Illkirch, France
| | - Pascale Cordier
- TRANSGENE S.A, 400 Boulevard Gonthier d'Andernach, 67400 Illkirch, France
| | - Eric Quemeneur
- TRANSGENE S.A, 400 Boulevard Gonthier d'Andernach, 67400 Illkirch, France
| | | | | | - Philippe Erbs
- TRANSGENE S.A, 400 Boulevard Gonthier d'Andernach, 67400 Illkirch, France
| |
Collapse
|
11
|
Komissarov A, Demidyuk I, Safina D, Roschina M, Shubin A, Lunina N, Karaseva M, Kostrov S. Cytotoxic effect of co-expression of human hepatitis A virus 3C protease and bifunctional suicide protein FCU1 genes in a bicistronic vector. Mol Biol Rep 2017; 44:323-332. [PMID: 28748410 DOI: 10.1007/s11033-017-4113-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Accepted: 07/19/2017] [Indexed: 12/20/2022]
Abstract
Recent reports on various cancer models demonstrate a great potential of cytosine deaminase/5-fluorocytosine suicide system in cancer therapy. However, this approach has limited success and its application to patients has not reached the desirable clinical significance. Accordingly, the improvement of this suicide system is an actively developing trend in gene therapy. The purpose of this study was to explore the cytotoxic effect observed after co-expression of hepatitis A virus 3C protease (3C) and yeast cytosine deaminase/uracil phosphoribosyltransferase fusion protein (FCU1) in a bicistronic vector. A set of mono- and bicistronic plasmid constructs was generated to provide individual or combined expression of 3C and FCU1. The constructs were introduced into HEK293 and HeLa cells, and target protein synthesis as well as the effect of 5-fluorocytosine on cell death and the time course of the cytotoxic effect was studied. The obtained vectors provide for the synthesis of target proteins in human cells. The expression of the genes in a bicistronic construct provide for the cytotoxic effect comparable to that observed after the expression of genes in monocistronic constructs. At the same time, co-expression of FCU1 and 3C recapitulated their cytotoxic effects. The combined effect of the killer and suicide genes was studied for the first time on human cells in vitro. The integration of different gene therapy systems inducing cell death (FCU1 and 3C genes) in a bicistronic construct allowed us to demonstrate that it does not interfere with the cytotoxic effect of each of them. A combination of cytotoxic genes in multicistronic vectors can be used to develop pluripotent gene therapy agents.
Collapse
Affiliation(s)
- Alexey Komissarov
- Laboratory of Protein Engineering, Institute of Molecular Genetics, Russian Academy of Science, 2 Kurchatova Sq., Moscow, Russia, 123182
| | - Ilya Demidyuk
- Laboratory of Protein Engineering, Institute of Molecular Genetics, Russian Academy of Science, 2 Kurchatova Sq., Moscow, Russia, 123182.
| | - Dina Safina
- Laboratory of Protein Engineering, Institute of Molecular Genetics, Russian Academy of Science, 2 Kurchatova Sq., Moscow, Russia, 123182
| | - Marina Roschina
- Laboratory of Protein Engineering, Institute of Molecular Genetics, Russian Academy of Science, 2 Kurchatova Sq., Moscow, Russia, 123182
| | - Andrey Shubin
- Laboratory of Protein Engineering, Institute of Molecular Genetics, Russian Academy of Science, 2 Kurchatova Sq., Moscow, Russia, 123182
| | - Nataliya Lunina
- Laboratory of Protein Engineering, Institute of Molecular Genetics, Russian Academy of Science, 2 Kurchatova Sq., Moscow, Russia, 123182
| | - Maria Karaseva
- Laboratory of Protein Engineering, Institute of Molecular Genetics, Russian Academy of Science, 2 Kurchatova Sq., Moscow, Russia, 123182
| | - Sergey Kostrov
- Laboratory of Protein Engineering, Institute of Molecular Genetics, Russian Academy of Science, 2 Kurchatova Sq., Moscow, Russia, 123182
| |
Collapse
|
12
|
Li Y, Li YF, Si CZ, Zhu YH, Jin Y, Zhu TT, Liu MY, Liu GY. CCL21/IL21-armed oncolytic adenovirus enhances antitumor activity against TERT-positive tumor cells. Virus Res 2016; 220:172-8. [PMID: 27157859 DOI: 10.1016/j.virusres.2016.05.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 05/03/2016] [Accepted: 05/04/2016] [Indexed: 01/31/2023]
Abstract
Multigene-armed oncolytic adenoviruses are capable of efficiently generating a productive antitumor immune response. The chemokine (C-C motif) ligand 21 (CCL21) binds to CCR7 on naïve T cells and dendritic cells (DCs) to promote their chemoattraction to the tumor and resultant antitumor activity. Interleukin 21 (IL21) promotes survival of naïve T cells while maintaining their CCR7 surface expression, which increases their capacity to transmigrate in response to CCL21 chemoattraction. IL21 is also involved in NK cell differentiation and B cell activation and proliferation. The generation of effective antitumor immune responses is a complex process dependent upon coordinated interactions of various subsets of effector cells. Using the AdEasy system, we aimed to construct an oncolytic adenovirus co-expressing CCL21 and IL21 that could selectively replicate in TERTp-positive tumor cells (Ad-CCL21-IL21 virus). The E1A promoter of these oncolytic adenoviruses was replaced by telomerase reverse transcriptase promoter (TERTp). Ad-CCL21-IL21 was constructed from three plasmids, pGTE-IL21, pShuttle-CMV-CCL21 and AdEasy-1 and was homologously recombined and propagated in the Escherichia coli strain BJ5183 and the packaging cell line HEK-293, respectively. Our results showed that our targeted and armed oncolytic adenoviruses Ad-CCL21-IL21 can induce apoptosis in TERTp-positive tumor cells to give rise to viral propagation, in a dose-dependent manner. Importantly, we confirm that these modified oncolytic adenoviruses do not replicate efficiently in normal cells even under high viral loads. Additionally, we investigate the role of Ad-CCL21-IL21 in inducing antitumor activity and tumor specific cytotoxicity of CTLs in vitro. This study suggests that Ad-CCL21-IL21 is a promising targeted tumor-specific oncolytic adenovirus.
Collapse
Affiliation(s)
- Yang Li
- Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, China-Japan Union Hospital, Jilin University, Changchun 130062, PR China
| | - Yi-Fei Li
- The Affiliated Hospital to Changchun University of Chinese Medicine, Changchun 130021, PR China
| | - Chong-Zhan Si
- Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, China-Japan Union Hospital, Jilin University, Changchun 130062, PR China
| | - Yu-Hui Zhu
- Second Hospital of Jilin University, Changchun, Jilin Province 130021, PR China
| | - Yan Jin
- Second Hospital of Jilin University, Changchun, Jilin Province 130021, PR China
| | - Tong-Tong Zhu
- Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, China-Japan Union Hospital, Jilin University, Changchun 130062, PR China
| | - Ming-Yuan Liu
- Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, China-Japan Union Hospital, Jilin University, Changchun 130062, PR China; Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, PR China
| | - Guang-Yao Liu
- Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, China-Japan Union Hospital, Jilin University, Changchun 130062, PR China.
| |
Collapse
|
13
|
Schipper H, Alla V, Meier C, Nettelbeck DM, Herchenröder O, Pützer BM. Eradication of metastatic melanoma through cooperative expression of RNA-based HDAC1 inhibitor and p73 by oncolytic adenovirus. Oncotarget 2015; 5:5893-907. [PMID: 25071017 PMCID: PMC4171600 DOI: 10.18632/oncotarget.1839] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Malignant melanoma is a highly aggressive cancer that retains functional p53 and p73, and drug unresponsiveness largely depends on defects in death pathways after epigenetic gene silencing in conjunction with an imbalanced p73/DNp73 ratio. We constructed oncolytic viruses armed with an inhibitor of deacetylation and/or p73 to specifically target metastatic cancer. Arming of the viruses is aimed at lifting epigenetic blockage and re-opening apoptotic programs in a staggered manner enabling both, efficient virus replication and balanced destruction of target cells through apoptosis. Our results showed that cooperative expression of shHDAC1 and p73 efficiently enhances apoptosis induction and autophagy of infected cells which reinforces progeny production. In vitro analyses revealed 100% cytotoxicity after infecting cells with OV.shHDAC1.p73 at a lower virus dose compared to control viruses. Intriguingly, OV.shHDAC1.p73 acts as a potent inhibitor of highly metastatic xenograft tumors in vivo. Tumor expansion was significantly reduced after intratumoral injection of 3 × 108 PFU of either OV.shHDAC1 or OV.p73 and, most important, complete regression could be achieved in 100% of tumors treated with OV.shHDAC1.p73. Our results point out that the combination of high replication capacity and simultaneous restoration of cell death routes significantly enhance antitumor activity.
Collapse
Affiliation(s)
- Holger Schipper
- Institute of Experimental Gene Therapy and Cancer Research, Rostock University Medical Center, Rostock, Germany; These authors contributed equally to the work
| | - Vijay Alla
- Institute of Experimental Gene Therapy and Cancer Research, Rostock University Medical Center, Rostock, Germany; These authors contributed equally to the work
| | - Claudia Meier
- Institute of Experimental Gene Therapy and Cancer Research, Rostock University Medical Center, Rostock, Germany
| | - Dirk M Nettelbeck
- Helmholtz University Group Oncolytic Adenoviruses, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Ottmar Herchenröder
- Institute of Experimental Gene Therapy and Cancer Research, Rostock University Medical Center, Rostock, Germany
| | - Brigitte M Pützer
- Institute of Experimental Gene Therapy and Cancer Research, Rostock University Medical Center, Rostock, Germany
| |
Collapse
|
14
|
Hammer K, Kazcorowski A, Liu L, Behr M, Schemmer P, Herr I, Nettelbeck DM. Engineered adenoviruses combine enhanced oncolysis with improved virus production by mesenchymal stromal carrier cells. Int J Cancer 2015; 137:978-90. [PMID: 25604186 DOI: 10.1002/ijc.29442] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 12/03/2014] [Accepted: 12/17/2014] [Indexed: 12/12/2022]
Abstract
Oncolytic viruses have demonstrated in pre-clinical and clinical studies safety and a unique pleiotropic activity profile of tumor destruction. Yet, their delivery suffers from virus inactivation by blood components and sequestration to healthy tissues. Therefore, mesenchymal stromal cells (MSCs) have been applied as carrier cells for shielded virus delivery to tumors after ex vivo infection with oncolytic viruses. However, infection and particle production by MSCs have remained unsatisfying. Here, we report engineered oncolytic adenoviruses (OAds) for improved virus production and delivery by MSCs. OAds are uniquely amenable to molecular engineering, which has facilitated improved tumor cell destruction. But for MSC-mediated regimens, OAd engineering needs to achieve efficient infection and replication in both MSCs and tumor cells. We show that an Ad5/3 chimeric OAd capsid, containing the adenovirus serotype 3 cell-binding domain, strongly increases the entry into human bone marrow-derived MSCs and into established and primary pancreatic cancer cells. Further, we reveal that OAd with engineered post-entry functions-by deletion of the anti-apoptotic viral gene E1B19K or expression of the death ligand TRAIL--markedly increased virus titers released from MSCs, while MSC migration was not hampered. Finally, these virus modifications, or viral expression of FCU1 for local 5-FC prodrug activation, improved tumor cell killing implementing complementary cytotoxicity profiles in a panel of pancreatic cancer cell cultures. Together, our study establishes post-entry modification of OAd replication for improving virus delivery by carrier cells and suggests a panel of optimized OAds for future clinical development in personalized treatment of pancreatic cancer.
Collapse
Affiliation(s)
- Katharina Hammer
- Oncolytic Adenovirus Group, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Adam Kazcorowski
- Molecular OncoSurgery, German Cancer Research Center (DKFZ) and Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Heidelberg, Germany
| | - Li Liu
- Molecular OncoSurgery, German Cancer Research Center (DKFZ) and Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Heidelberg, Germany
| | - Michael Behr
- Oncolytic Adenovirus Group, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Peter Schemmer
- Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Heidelberg, Germany
| | - Ingrid Herr
- Molecular OncoSurgery, German Cancer Research Center (DKFZ) and Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Heidelberg, Germany
| | - Dirk M Nettelbeck
- Oncolytic Adenovirus Group, German Cancer Research Center (DKFZ), Heidelberg, Germany
| |
Collapse
|
15
|
Fernández-Ulibarri I, Hammer K, Arndt MAE, Kaufmann JK, Dorer D, Engelhardt S, Kontermann RE, Hess J, Allgayer H, Krauss J, Nettelbeck DM. Genetic delivery of an immunoRNase by an oncolytic adenovirus enhances anticancer activity. Int J Cancer 2014; 136:2228-40. [PMID: 25303768 DOI: 10.1002/ijc.29258] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 09/22/2014] [Indexed: 01/27/2023]
Abstract
Antibody therapy of solid cancers is well established, but suffers from unsatisfactory tumor penetration of large immunoglobulins or from low serum retention of antibody fragments. Oncolytic viruses are in advanced clinical development showing excellent safety, but suboptimal potency due to limited virus spread within tumors. Here, by developing an immunoRNase-encoding oncolytic adenovirus, we combine viral oncolysis with intratumoral genetic delivery of a small antibody-fusion protein for targeted bystander killing of tumor cells (viro-antibody therapy). Specifically, we explore genetic delivery of a small immunoRNase consisting of an EGFR-binding scFv antibody fragment fused to the RNase Onconase (ONC(EGFR)) that induces tumor cell death by RNA degradation after cellular internalization. Onconase is a frog RNase that combines lack of immunogenicity and excellent safety in patients with high tumor killing potency due to its resistance to the human cytosolic RNase inhibitor. We show that ONC(EGFR) expression by oncolytic adenoviruses is feasible with an optimized, replication-dependent gene expression strategy. Virus-encoded ONC(EGFR) induces potent and EGFR-dependent bystander killing of tumor cells. Importantly, the ONC(EGFR)-encoding oncolytic adenovirus showed dramatically increased cytotoxicity specifically to EGFR-positive tumor cells in vitro and significantly enhanced therapeutic activity in a mouse xenograft tumor model. The latter demonstrates that ONC(EGFR) is expressed at levels sufficient to trigger tumor cell killing in vivo. The established ONC(EGFR)-encoding oncolytic adenovirus represents a novel agent for treatment of EGFR-positive tumors. This viro-antibody therapy platform can be further developed for targeted/personalized cancer therapy by exploiting antibody diversity to target further established or emerging tumor markers or combinations thereof.
Collapse
Affiliation(s)
- Inés Fernández-Ulibarri
- Oncolytic Adenovirus Group, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 242, 69120 Heidelberg, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Enhanced antitumor efficacy of a novel oncolytic adenovirus combined with temozolomide in the treatment of melanoma in vivo. J Cancer Res Clin Oncol 2014; 141:75-85. [PMID: 25103017 DOI: 10.1007/s00432-014-1763-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Accepted: 06/21/2014] [Indexed: 12/31/2022]
Abstract
PURPOSE The aim of this study was to investigate the effect of Ki67-ZD55-IL-24 with temozolomide (TMZ) against melanoma in mice. METHODS Seventy-eight mice with subcutaneous injection of A375 cells (2 × 10(6)) into the right flank were randomized to receive phosphate buffered saline (PBS), Ki67-ZD55, Ki67-ZD55-IL-24, TMZ, TMZ + Ki67-ZD55, and TMZ + Ki67-ZD55-IL-24. Six mice were killed in each group 10 days after intervention for detecting IL-24 mRNA and protein expression. The remaining mice were monitored to draw the body weight change curve and tumor growth curve, and killed 30 days after intervention. Tumors were excised and weighted. The morphology of tumor tissues was determined by hematoxylin and eosin (HE) staining, and the apoptosis index and rate of apoptotic cells were determined by TUNEL assay and AnnexinV-FITC/PI double staining, respectively. RESULTS The Ki67-ZD55-IL-24-treated group generated much more reactive oxygen species than the untreated group. There was no significant difference in IL-24 expression between Ki67-ZD55-IL-24 and TMZ + Ki67-ZD55-IL-24 groups. Immunohistochemical analysis and Western blot revealed that both the Ki67-ZD55 and Ki67-ZD55-IL-24 could significantly reduce the expression of MGMT. Toxicity assessments demonstrated that mice in the three groups that received TMZ exhibited significant body weight loss following treatment. HE staining showed that TMZ + Ki67-ZD55-IL-24 group had much fewer karyokinesis in the tumors, compared with other groups. The apoptosis index of tumor tissues and the rate of apoptotic cells were significantly higher in TMZ + Ki67-ZD55-IL-24 group than in other groups (all P < 0.05). CONCLUSIONS These findings indicate this novel strategy holds promising potentials for treatment of malignant melanoma.
Collapse
|
17
|
Chemovirotherapy of malignant melanoma with a targeted and armed oncolytic measles virus. J Invest Dermatol 2012; 133:1034-42. [PMID: 23223133 DOI: 10.1038/jid.2012.459] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Effective treatment modalities for advanced melanoma are desperately needed. An innovative approach is virotherapy, in which viruses are engineered to infect cancer cells, resulting in tumor cell lysis and an amplification effect by viral replication and spread. Ideally, tumor selectivity of these oncolytic viruses is already determined during viral cell binding and entry, which has not been reported for melanoma. We engineered an oncolytic measles virus entering melanoma cells through the high molecular weight melanoma-associated antigen (HMWMAA) and proved highly specific infection and spread in melanoma cells. We further enhanced this oncolytic virus by inserting the FCU1 gene encoding the yeast-derived prodrug convertases cytosine deaminase and uracil phosphoribosyltransferase. Combination treatment with armed and retargeted MV-FCU1-αHMWMAA and the prodrug 5-fluorocytosine (5-FC) led to effective prodrug conversion to 5-fluorouracil, extensive cytotoxicity to melanoma cells, and excessive bystander killing of noninfected cells. Importantly, HMWMAA-retargeted MV showed antitumor activity in a human xenograft mouse model, which was further increased by the FCU1/5-FC prodrug activation system. Finally, we demonstrated susceptibility of melanoma skin metastasis biopsies to HMWMAA-retargeted MV. The highly selective, entry-targeted and armed oncolytic virus MV-FCU1-αHMWMAA may become a potent building block of future melanoma therapies.
Collapse
|
18
|
Ketzer P, Haas SF, Engelhardt S, Hartig JS, Nettelbeck DM. Synthetic riboswitches for external regulation of genes transferred by replication-deficient and oncolytic adenoviruses. Nucleic Acids Res 2012; 40:e167. [PMID: 22885302 PMCID: PMC3505972 DOI: 10.1093/nar/gks734] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Therapeutic gene transfer by replication-defective viral vectors or, for cancer treatment, by replication-competent oncolytic viruses shows high promise for treatment of major diseases. To ensure safety, timing or dosing in patients, external control of therapeutic gene expression is desirable or even required. In this study, we explored the potential of artificial aptazymes, ligand-dependent self-cleaving ribozymes, as an innovative tool for regulation of therapeutic gene expression. Importantly, aptazymes act on RNA intrinsically, independent of regulatory protein–nucleic acid interactions and stoichiometry, are non-immunogenic and of small size. These are key advantages compared with the widely used inducible promoters, which were also reported to lose regulation at high copy numbers, e.g. after replication of oncolytic viruses. We characterized aptazymes in therapeutic gene transfer utilizing adenovectors (AdVs), adeno-associated vectors (AAVs) and oncolytic adenoviruses (OAds), which are all in advanced clinical testing. Our results show similar aptazyme-mediated regulation of gene expression by plasmids, AdVs, AAVs and OAds. Insertion into the 5′-, 3′- or both untranslated regions of several transgenes resulted in ligand-responsive gene expression. Notably, aptazyme regulation was retained during OAd replication and spread. In conclusion, our study demonstrates the fidelity of aptazymes in viral vectors and oncolytic viruses and highlights the potency of riboswitches for medical applications.
Collapse
Affiliation(s)
- Patrick Ketzer
- Helmholtz-University Group Oncolytic Adenoviruses, Deutsches Krebsforschungszentrum (DKFZ, German Cancer Research Center) and Department of Dermatology, Heidelberg University Hospital, Im Neuenheimer Feld 242, 69120 Heidelberg, Germany
| | | | | | | | | |
Collapse
|
19
|
Seymour LW. Oncolytic Virotherapy: Combining First-Rate Science with an Unmet Clinical Need. Hum Gene Ther 2011; 22:387-8. [DOI: 10.1089/hum.2011.3220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Leonard W. Seymour
- Department of Oncology, University of Oxford, Oxford OX3 7DQ, United Kingdom
| |
Collapse
|