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Rational Modification of Oncolytic Viruses Using small RNAs

PI(s)
Mathias F. Leber

Contributing CCU members
Adrian Eilert, Katia Dittus, Marie Szczeponik, Jessica Albert, Birgit Hoyler, Stefanie Sawall
Scientific staff (alumni): Sophie Anker, Jan Dessila, Hans-Martin Singh, Marc-Andrea Bärtsch, Sascha Bossow

Virotherapy is a novel treatment modality that employs tumor-specific, oncolytic viruses (OVs), which directly lyse cancer cells and induce an anti-tumor immune response. Small RNAs are a broad class of endogenous or exogenous nucleic acids that are defined by their limited size (

In this project, we explore multiple ways to rationally modify and thereby improve OVs using small RNA-based systems and technologies.

Sub-project: "Control of OV replication by genomic insertion of synthetic microRNA target sequences for enhanced safety": Restriction of OV replication to tumor cells is paramount for safety when administering OVs to cancer patients. Therefore, we have developed and optimized a microRNA-based post-entry restriction system that blocks oncolytic measles virus replication in healthy cells. In this approach, synthetic target sequences for microRNAs, which are lost during tumorigenesis, but are present in healthy cells, are incorporated into the viral genome. Thereby, virus replication in healthy cells is suppressed by the host cell's RNAi-machinery while replication in and destruction of tumor cells is unhindered.

Sub-project: "Boosting OV efficacy by encoding therapeutic small RNAs": Here, we are developing genetically engineered viruses which encode small RNAs for targeted knock-down of host factors restricting OV replication specifically in tumor cells. Thereby, we aim to increase the oncolytic potency and therapeutic efficacy of OVs.

Ultimately, we aim to develop these rationally modified OVs into clinically administered therapeutics for the benefit of cancer patients.

Publications

  • Oncolytic Measles Virus Encoding MicroRNA for Targeted RNA Interference Anker, S.C.; Szczeponik, M.G.; Dessila, J.; Dittus, K.; Engeland, C.E.; Jäger, D.; Ungerechts, G.; Leber, M.F. Viruses 2023 Jan 22;15(2):308
  • MicroRNA-sensitive oncolytic measles virus for chemovirotherapy of pancreatic cancer. Singh HM, Leber MF, Bossow S, Engeland CE, Dessila J, Grossardt C, Zaoui K, Bell JC, Jäger D, von Kalle C, Ungerechts G. Molecular Therapy Oncolytics 2021 May 5;21:340-355.
  • Engineering and combining oncolytic measles virus for cancer therapy. Leber MF, Neault S, Jirovec E, Barkley R, Said A, Bell JC, Ungerechts G. Cytokine & Growth Factor Reviews 2020 Jul 3:S1359-6101(20)30149-0.
  • Enhanced Control of Oncolytic Measles Virus Using MicroRNA Target Sites. Leber MF, Baertsch MA, Anker SC, Henkel L, Singh HM, Bossow S, Engeland CE, Barkley R, Hoyler B, Albert J, Springfeld C, Jäger D, von Kalle C, Ungerechts G. Molecular Therapy Oncolytics 2018 Apr 12;9:30-40.
  • MicroRNA-mediated multi-tissue detargeting of oncolytic measles virus. Baertsch MA, Leber MF, Bossow S, Singh M, Engeland CE, Albert J, Grossardt C, Jäger D, von Kalle C, Ungerechts G. Cancer Gene Therapy 2014 Sep;21(9):373-80.
  • MicroRNA-sensitive oncolytic measles viruses for cancer-specific vector tropism. Leber MF, Bossow S, Leonard VH, Zaoui K, Grossardt C, Frenzke M, Miest T, Sawall S, Cattaneo R, von Kalle C, Ungerechts G. Molecular Therapy 2011 Jun;19(6):1097-106.

Funding
Physician-Scientist Fellowship to MFL, Heidelberg University, Medical Faculty

Oncolytic Adenoviruses: Selecting and Engineering Adenovirus Serotypes with Improved Oncolytic and Immunostimulatory Potency

The image displays a grid divided into four sections labeled I to IV, representing data on VP per cell. Each section shows varying levels of green fluorescence against a dark background, indicating different concentrations or distributions of a specific substance. The overall appearance is scientific and analytical.
Different adenovirus serotypes show greatly varying degrees of tumor cell infection and spread as determined by transgene expression (GFP) using an Incucyte automated microscopy system. Cells were infected with ten-fold dilutions of GFP-encoding viruses, rows represent technical replicates and roman numerals denote adenovirus serotypes. © dkfz.de

PI(s)
Dirk M. Nettelbeck

Contributing CCU members
Jonny Hertzog, Levi Antonius Kuon, Jessica Genz, Marlene Khin, Rainer Kuhn

Cooperation partners
Claudia Ball, National Center for Tumor Diseases, Dresden and German Cancer Research Center, Heidelberg, Germany
Anja Ehrhardt and Wenli Zhang, University of Witten-Herdecke, Germany
Benedikt Brors and Sadaf Shabbir Mughal, German Cancer Research Center, Heidelberg, Germany
Niels Halama, National Center for Tumor Diseases, Heidelberg; University Hospital Heidelberg and German Cancer Research Center, Heidelberg, Germany

Oncolytic adenoviruses possess many advantageous features for applications in virotherapy, including unique mechanisms of tumor-selectivity, immunostimulatory activity supporting oncolytic tumor vaccination and various engineering opportunities for adapting or improving oncolytic functions. However, previous work has focused on one of now >100 known adenovirus serotypes.

The aim of this program is to characterize the oncolytic and immunological properties of adenovirus serotypes and engineer lead candidates towards a new generation of efficiency-enhanced oncolytic adenoviruses. To this end, we systematically screen recently established adenovirus libraries (cooperation with Anja Ehrhardt, Univ. of Witten-Herdecke) in tumor and immune cell cultures and in sophisticated patient-derived pre-clinical tumor models (cooperation with our colleagues at NCT and DKFZ, Claudia Ball and Niels Halama). Comprehensive analyses include various virological and immunological parameters at the molecular and cellular level and in the context of tumor tissue. Emerging adenovirus serotypes with superior oncolytic and immunological features will be engineered to incorporate stringent tumor-selectivity. To this end, we utilize new technologies for modification of large viral genomes that are applicable irrespective of adenovirus serotype.

These next generation oncolytic adenoviruses will allow for further exploration of combination immunotherapy and/or "arming" with therapeutic genes, and ultimately for clinical translation within the CCU framework.

Funding
Wilhelm Sander-Stiftung, project grant (to DMN)
DKFZ International Postdoc Program
German Cancer Aid (Fellowship to LAK)
Dr. Rolf M. Schwiete Stiftung, project grant

Mathematical Modeling of Combined Oncolytic Immunotherapy

The image illustrates a scientific model involving a bacterium, antibodies, and a cell, along with relevant equations for understanding interactions. Arrows indicate relationships between components. A diagram of a petri dish and a syringe is included, representing laboratory research.
Data of immunotherapeutic treatments (top) generated using in vitro and in vivo tumor models (bottom right) are integrated into a mathematical model (bottom left) to allow for in silico prediction of optimal treatment schedules for further development and ultimately clinical translation. © dkfz.de

PI(s)
Christine E. Engeland, Johannes P. W. Heidbüchel

Contributing CCU members
Jessica Albert, Birgit Hoyler, Stefanie Sawall

Cooperation partners
Daniel Abate-Daga and Dr. Heiko Enderling, Moffitt Cancer Center, Tampa, FL, USA
Patrick Schmidt and Dirk Jäger, National Center for Tumor Diseases, University Hospital Heidelberg and German Cancer Research Center Heidelberg
Richard Harbottle, German Cancer Research Center Heidelberg
Michael Breckwoldt, University Hospital Heidelberg and German Cancer Research Center Heidelberg

Cancer immunotherapies, such as immune checkpoint blockade and chimeric antigen receptor (CAR) T cell therapy, have recently proven successful in numerous pre-clinical and clinical studies. However, critical challenges including toxicities and lack of efficacy, especially against solid tumors, have yet precluded benefit for the majority of patients. Combination with oncolytic viruses which directly lyse tumor cells and stimulate an anti-tumor immune response has been shown to be a viable option to increase the therapeutic window of immunotherapy. However, the complexity of the immune system and the plethora of possible combinations rule out comprehensive testing to identify optimal treatment schedules. To address these challenges, we are developing mathematical models of combination immunovirotherapies together with our collaborators from Moffitt Cancer Center in Tampa, FL, Dr. Daniel Abate-Daga and Dr. Heiko Enderling.

Lines of research include parametrization of the model with quantitative experimental data. In interdisciplinary collaborations, we are working together with Jessica Hunger and Dr. Dr. Michael Breckwoldt (DKFZ) on imaging approaches and with Aileen Berger, Dr. Patrick Schmidt, Prof. Dr. Dirk Jäger (University Hospital Heidelberg), Alice de Roia, Dr. Matthias Bozza and Prof. Dr. Richard Harbottle (DKFZ) on CAR design and development.

Following validation and refinement, the models will be used to simulate outcomes of theoretical combination therapies in order to prioritize the most promising treatment approaches for further development. Crucial parameters in the system will be identified as targets for therapeutic intervention. This innovative workflow will accelerate clinical translation of combination immunotherapies for the benefit of cancer patients.

Publications

  • Mathematical modeling of oncolytic virotherapy. Heidbuechel JPW, Abata-Daga D, Engeland CE, Enderling H. In: Engeland CE (ed.) Oncolytic Viruses. Methods in Molecular Biology vol 2058, Humana, New York, NY, ISBN 978-1-4939-9793-0.
  • Targeted BiTE Expression by an Oncolytic Vector Augments Therapeutic Efficacy Against Solid Tumors. Speck T*, Heidbuechel JPW*, Veinalde R, Jaeger D, von Kalle C, Ball CR, Ungerechts G, Engeland CE. Clinical Cancer Research 2018; 24: 2128-37.
  • Fighting cancer with mathematics and viruses. Santiago DN*, Heidbuechel JPW*, Kandell WM, Walker R, Djeu J, Engeland CE, Abate-Daga D, Enderling H. Viruses 2017; 9(9), 239.

Funding
Wilhelm Sander Foundation, Grant No. 2018.058.1 (to CEE), NCT Heidelberg School of Oncology (HSO²), Postdoctoral Fellowship in Clinical Cancer Research (to JPWH)

Heterotypic Spheroid Model Development for Preclinical Studies of Virotherapy-induced Changes of Tumor Microenvironment

The image depicts a series of diagrams illustrating the progression of tumor cells within a tissue structure. Stages show the arrangement of tumor cells, stroma, vasculature, and immune cells, highlighting their interactions over time. The focus is on cellular dynamics in a tumor microenvironment.
Establishment of monotypic (A) and heterotypic: double (B), triple (C) and quadruple (D) coculture pancreatic cancer spheroids © dkfz.de

PI(s)
Assia Angelova

Contributing CCU members
Jean Rommelaere (Prof. Emeritus), Alexandra Just, Milena Barf

Rodent protoparvoviruses possess natural tumor-killing (oncolytic) properties. Furthermore, these viruses, H-1PV in particular, are capable of reversing tumor-driven immune suppression through the induction of immunogenic tumor cell death and the establishment of a proinflammatory tumor microenvironment. H-1PV immunostimulating effects have been demonstrated both preclinically and in early phase clinical trials: ParvOryx01 (glioblastoma) (https://clinicaltrials.gov/ct2/show/NCT01301430) and ParvOryx02 (pancreatic cancer) (https://clinicaltrials.gov/ct2/show/NCT02653313).
Parvovirotherapy has potential as anticancer strategy and the prospects of development of parvovirus-based combinatorial treatments urge the need for relevant preclinical models applicable to both basic and translational viro-immunotherapy research. The main goal of our team is to establish in vitro systems, which mimic the structural and functional complexity of the tumor microenvironment, including the interplay between stroma, vasculature and immune cells. We apply a methylcellulose-based hanging drop approach to generate double, triple and quadruple heterotypic spheroids consisting of tumor, fibroblast, endothelial and immune cells. These complex 3D systems may be subjected to various viro-immunotherapeutic treatments and further implemented into transwell co-culture, organotypic or animal models.
We are currently focused on pancreatic cancer spheroid model establishment. We are also pursuing the reproducible generation of non-Hodgkin lymphoma (NHL) spheroids, taking up the challenge of the intrinsically low 3D growth capacity of blood cancer cells. Diffuse large B cell lymphoma and cutaneous T cell lymphoma, two NHL subtypes presently lacking pertinent tumor microenvironment recapitulation in vitro, are in the spotlight of our research activities. The ultimate goal of our team is the establishment of a translationally relevant, patient tumor material-based heterotypic spheroid model as a novel platform for preclinical viro-immunotherapeutic testing.
In collaboration with K. Geletneky (Darmstadt, Germany), B. Leuchs (DKFZ), J. Nüesch (DKFZ), A. Marchini (DKFZ and LIH, Luxembourg).

Publications

  • Fluorescence In Situ Hybridization (FISH) Detection of Viral Nucleic Acids in Oncolytic H-1 Parvovirus-Treated Human Brain Tumors. Kiprianova I, Just A, Leuchs B, Rommelaere J, Angelova AL. Methods Mol Biol 2020; 2058: 295-306.
  • Immune Conversion of Tumor Microenvironment by Oncolytic Viruses: The Protoparvovirus H-1PV Case Study. Marchini A, Daeffler L, Pozdeev VI, Angelova A, Rommelaere J. Front Immunol 2019; 10: 1848.
  • Immune System Stimulation by Oncolytic Rodent Protoparvoviruses. Angelova A, Rommelaere J. Viruses 2019; 11: 415.
  • Oncolytic H-1 Parvovirus Shows Safety and Signs of Immunogenic Activity in a First Phase I/IIa Glioblastoma Trial. Geletneky K, Hajda J, Angelova AL, Leuchs B, ...Just A, ....Rommelaere J. Mol Ther 2017, 25: 2620-34.
  • The Oncolytic Virotherapy Era in Cancer Management: Prospects of Applying H-1 Parvovirus to Treat Blood and Solid Cancers. Angelova AL, Witzens-Harig M, Galabov AS, Rommelaere J. Front Oncol 2017; 7: 93.

RadioViroTherapy for Treatment of Refractory Solid Cancer

An infographic titled "Radiovirology (RVTx)" outlines three main components: optimal dosing and scheduling of radiotherapy, molecular identification of action mechanisms, and modifications of RVTx. It illustrates elements like radiation symbols and virus representations to conceptualize the therapeutic approach combining radiation and the measles virus.
Project overview: This project focusses on a systematic development of radiovirotherapy (RVTx) followed by an in-depth molecular and functional characterization of induced mechanisms of action. © dkfz.de

PI(s)
Mathias F. Leber, Guy Ungerechts

Contributing CCU members
Katia Dittus, Assia Angelova, Jessica Genz, Birgit Hoyler, Stefanie Sawall

Cooperation Partners
Laurent Daeffler, Institut Pluridisciplinaire Hubert Curien, CNRS/University of Strasbourg, France
Karim Plath, Department of Otorhinolaryngology, Head and Neck Surgery, Heidelberg University Hospital, Heidelberg, German
Claudia Ball, National Center for Tumor Diseases, Dresden and German Cancer Research Center, Heidelberg, Germany
Richard Harbottle, German Cancer Research Center Heidelberg, Germany
Rienk Offringa, German Cancer Research Center, Heidelberg, Germany

Refractory tumors such as pancreatic ductal adenocarcinoma (PDAC), head and neck squamous cell carcinoma (HNSCC) or glioblastoma (GBM) remain a major challenge in medical oncology. To address the limited clinical efficacy of current standard therapies, we aim to investigate virotherapy using oncolytic measles virus (MeV) or parvovirus (PV) combined with radiotherapy. We hypothesize that combined radiovirotherapy (RVTx) may elicit synergistic anti-cancer effects and induce a sustained anti-tumor immune response.

We are analyzing different dosing schedules of radiation and oncolytic MeV and have confirmed synergy of RVTx in HNSCC and PDAC cell lines in vitro. An in-depth molecular and functional characterization revealed elevated levels of immunogenic cell death (ICD) in response to RVTx, measured by classical ICD markers. To investigate therapeutic effects of RVTx in models of high translational relevance, we employ various ex vivo models such as patient-derived tumor explant samples or spheroids/organoids. We aim at elucidating susceptibility to viral infection as well as decipher innate and adaptive immune responses upon RVTx. Recently, we expanded our radiation platform to include particle radiation. In the future, the molecular and functional characterization as well as immunophenotyping will allow for a rational modification of RVTx in order to develop combination virotherapy regimens for improved treatment efficacy.

Funding
Alois Hirdt-Erben und Wieland-Stiftung Heidelberg
Bi-national ANR-DFG grant: Combination of proton radiations and oncolytic viruses to eradicate cancer – PROTOVEC; Agence nationale de la recherche & German Research Foundation.

Viro-antibody therapy: Engineering oncolytic adenoviruses for genetic delivery of therapeutic antibodies

The image illustrates a detailed diagram of molecular interactions, featuring various colored molecules connecting across a cell membrane. Key components include proteins, receptors, and enzymes, demonstrating biochemical processes essential for cellular function and communication. The left and right sides represent different molecular structures and interactions.
Schematic depiction of the principle of a combination therapy with oncolytic Adenoviruses (oAds) and multiple encoded recombinant antibodies, here T-cell engagers. OAds infect and lyse tumor cells, while at the same time directing the production of multiple T-cell engagers, specific for different targets to address the problem of tumor heterogeneity, by the tumor cells. The T-cell engagers are able to reach tumor cells inaccessible to the virus, mediating their destruction through T-cells. | © dkfz.de

PI(s)
Dirk M. Nettelbeck

Contributing CCU members
Eleonora Prodi, Marleen Trapp, Rainer Kuhn, Jessica Albert

Cooperation partners
Roland Kontermann and Oliver Seifert, University of Stuttgart, Germany

Oncolytic viruses specifically infect tumor cells followed by virus replication and spread in the tumor, thereby lysing the infected tumor cells. These features also recommend oncolytic viruses for targeted and self-amplifying delivery of therapeutic proteins to tumors by inserting the corresponding genes into the viruses' genomes. As an example, oncolytic viruses facilitate local and prolonged expression of therapeutic antibodies in tumors (viro-antibody therapy, Kontermann et al., 2021). This approach might facilitate superior tumor perfusion compared with standard antibody treatment and combine viral oncolysis with bystander killing of non-infected tumor cells.

The aim of this program is to engineer oncolytic adenoviruses for the genetic delivery of small recombinant antibody therapeutics targeting a set of tumor antigens. In a collaboration with Roland Kontermann of the University of Stuttgart, we explore different recombinant antibody formats and antibody-mediated effector mechanisms for their suitability for viro-antibody therapy. Moreover, we engineer oncolytic adenoviruses to investigate and optimize different expression strategies for potent and tumor-specific (co-)expression of antibodies. For the resulting antibody-delivering oncolytic adenoviruses, virus- and antibody-mediated activities as well as combined therapeutic efficacy are analyzed in cell cultures and tumor models in vitro and in vivo.

These developed oncolytic virus platforms will allow for the switching of antibody specificities and/or effector domains to facilitate broader applications in cancer therapy.

Publications

  • Boos MA, Seifert O, Sawall S, Genz J, Huber A, Hofmann I, Kontermann RE, Ungerechts G, Nettelbeck DM. Oncolytic adenoviruses encoding bispecific T cell engagers or a novel trispecific T cell engager for dual-targeting of c-MET and EGFR. Mol Ther Oncol 2026. 34(1): p. 201106. 
  • Kontermann RE, Ungerechts G, Nettelbeck DM. Viro-antibody therapy: engineering oncolytic viruses for genetic delivery of diverse antibody-based biotherapeutics. mAbs 2021;13: 1982447.
  • Fernandez-Ulibarri I, Hammer K, Arndt MA, 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 2015;136: 2228-40.

Funding
Studienstiftung des Deutschen Volkes (German National Academic Foundation)

Boosting oncolytic viruses by small molecule compounds

The image depicts a diagram illustrating the interaction between various virus platforms and cell systems, focusing on treatment schedules. It highlights the mode of cell death, cellular targets, and factors like viral replication kinetics and transgene expression, with annotations for different virus types and models.
Combination of oncolytic viruses with small molecule compounds for maximized anti-tumor response. Treatment conditions will be optimized prior to the investigation of underlying mechanisms of action. Finally, therapeutic efficacy of PVTx will be assessed in different preclinical tumor models. | © dkfz.de

PI(s)
Mathias F. Leber, Dirk M. Nettelbeck, Guy Ungerechts

Contributing CCU members
Marie Szczeponik, Juliane Hastedt, Adrian Eilert, Birgit Hoyler, Jessica Genz, Stefanie Sawall

Alumni: Marie Körner

Cooperation partners
Tommy Alain, Children's Hospital of Eastern Ontario (CHEO), Research Institute I, Ottawa, ON, Canada

Karim Plath, Department of Otorhinolaryngology, Head and Neck Surgery, Heidelberg University Hospital, Heidelberg, Germany

In recent years, oncolytic viruses have emerged as a promising therapy modality for solid and recurrent tumors. However, their ability to elicit durable remissions in patients is limited. In this project we aim at combining oncolytic measles and adenoviruses with small molecule compounds (pharmacovirotherapy, PVTx) to overcome limitations to virotherapy and achieve a better therapeutic efficacy.

Small molecules are a class of therapeutic drugs that can specifically target pathways and counteract resistance factors in the host cells and can therefore act as an optimal partner for virotherapy.

Together with our cooperation partners, we aim to screen small molecules in their ability to boost the viruses' cytolytic activity, performing several viability assays. We will be further investigating the compounds' effect on viral replication and transgene expression. In a next step, we will perform in-depth analyses of the mechanisms underlying potential synergism. Among other aspects, we will be looking at the mode of cell death, as well as potential target proteins in the host cells, e.g. by knocking down specific targets using siRNAs.
Finally, we will be assessing the therapeutic efficacy in preclinical tumor models with the objective of eventually translating our results into the clinic.

Funding
Deutsche Krebshilfe (Mildred-Scheel-Doktorandenprogramm)

RNA switch-inducible genetic delivery of biotherapeutics by oncolytic viruses

This diagram illustrates an inducible "armed" oncolytic virus. It shows the process of gene expression being turned “OFF” or “ON,” indicating how the virus can trigger viral oncolysis and subsequently lead to the delayed expression of therapeutic proteins in targeted cells.
Exploring controllable gene delivery by oncolytic viruses using RNA-ON switches triggered by the medically applicable ligand tetracycline. Addition of the ligand induces therapeutic gene expression once viral oncolysis and spread reach their peak in order to minimize counteracting effects on viral replication and to aim for enhanced therapeutic potency. | © dkfz.de

PI(s)
Dirk M. Nettelbeck

Contributing CCU members
Laura Kayser, Pierre Gommeringer, Jessica Albert, Stefanie Sawall

Cooperation partners
Jörg Hartig, University of Konstanz, Germany

Most oncolytic viruses, including adenoviruses, provide the unique opportunity to express therapeutic proteins in tumors for improved therapeutic outcome. As such, the genetic delivery of biotherapeutics, including apoptosis-inducing ligands, fusion proteins, cytokines, or recombinant antibodies is under investigation. However, this approach may be challenged by interference with oncolytic virus replication or toxic side effects. The aim of our work is to develop, in close collaboration with Jörg Hartig's group at the University of Konstanz, RNA switches for ligand-dependent regulation of oncolytic virus-delivered therapeutic genes, in order to facilitate optimal timing or as safety switch-off.

RNA switches are attractive tools for gene regulation as they require minimal genetic space, do not depend on the expression of potentially antigenic foreign regulatory proteins and facilitate regulation of viruses with DNA as well as RNA genomes.

In previous collaborative work, we have shown proof-of-principle for RNA switch-regulated expression both of oncolytic virus-mediated transgene expression and of oncolytic virus replication (DNA and RNA viruses) using a model aptazyme, which is a RNA sequence combining a ligand-binding aptamer and a self-cleaving ribozyme.

In on-going work, we generate and analyze medically applicable eukaryotic RNA switch designs, optimize their performance, and investigate functional insertion sites in oncolytic virus genomes. Ultimately, we will investigate different approaches for enhancing therapeutic potency of oncolytic viruses without compromising their safety by RNA switch-inducible expression of therapeutic payloads.

Publications

  • 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 research 2012;40: e167.
  • Ketzer P, Kaufmann JK, Engelhardt S, Bossow S, von Kalle C, Hartig JS, Ungerechts G, Nettelbeck DM. Artificial riboswitches for gene expression and replication control of DNA and RNA viruses. Proceedings of the National Academy of Sciences of the United States of America 2014;111: E554-62.

Funding
German Cancer Aid (Deutsche Krebshilfe), project grant

Oncolytic vaccination therapy for treatment of solid cancer

PI(s)
Mathias F. Leber, Guy Ungerechts

Contributing CCU members
Juliane K. Hastedt, Birgit Hoyler, Jessica Genz, Stefanie Sawall

Cooperation Partners
Angelika Riemer, German Cancer Research Center, Heidelberg, Germany
 

The idea of administering therapeutic cancer vaccines has been around for several decades. It is hypothesized that the immunogenic context of the tumor antigen delivery induces a T-cell anti-tumor response leading to long-term immunity. Although clinical trials involving a variety of cancer vaccine designs have been conducted, the successful translation into routine oncology has been slow. A major challenge seems to be the lacking immunogenicity of previously developed vaccines given the various immunosuppressive mechanisms employed by cancer cells.

In this project, we aim at developing an oncolytic virus-based therapeutic cancer vaccine for treatment of solid cancer. Further details can be provided upon request.

Funding
Deutsche Krebshilfe, Mildred Scheel Fellowship

Exploiting chimeric oncogenic transcription factors to target therapeutic viruses to pediatric tumors

PI(s)
Dirk M. Nettelbeck with cooperation partner Thomas G. P. Grünewald
 

Contributing CCU members
Eleonora Prodi, Marleen Trapp, Marlene Khin

Cooperation Partners
Thomas G. P. Grünewald, Division of Translational Pediatric Sarcoma Research, German Cancer Research Center (DKFZ), Heidelberg, Germany
 

The outcome of children, adolescents, and young adults with high-risk sarcomas, such as Ewing sarcoma (EwS) and alveolar rhabdomyosarcoma (ARMS), is still unacceptably low. These tumors (and other aggressive cancers) are fueled by and addicted to chimeric oncogenic transcription factors (OTFs) generated by chromosomal translocations that fuse otherwise unrelated DNA-binding and transactivating domains. Due to their tumor-specific expression, OTFs are in principle ideal therapeutic targets, but thus far, all attempts to completely suppress their activity have been unsuccessful which is why they are often classified as being undruggable. In collaboration with Thomas Grünewald's lab, we challenge this dogma with a novel strategy to leverage, rather than to suppress, OTFs by exploiting their exquisite neomorphic DNA-binding preferences: Strikingly, in both EwS and ARMS, the respective OTFs can bind to completely different DNA sequences than their wildtype constituting TFs, thus conveying outstanding tumor-selective transcription control.

Therapeutic viruses have been developed for treatment of cancer by tumor-restricted viral infection, replication, cell lysis and spread. Such virotherapies critically depend on the restriction of virus replication to tumor cells. Based on own pioneering work (Hölting et al. 2022), this project exploits neomorphic OTF-binding regulatory DNA elements to restrict the expression of essential viral genes and therapeutic payloads to EwS, ARMS and other tumors. We plan to genetically engineer the viral genomes and to analyze their tumor-restricted activation and therapeutic gene expression and resulting therapeutic activity in tumor cell lines and established pre-clinical tumor models.

The resulting therapeutic viruses are candidates for further development toward clinical application in the translational program of our unit. Furthermore, applications of the OTF-mediated targeting strategy to other tumors and other therapeutic viruses is envisioned.

Publications

  • Hölting TLB, Cidre-Aranaz F, Matzek D, Popper B, Jacobi SJ, Funk CM, Geyer FH, Li J, Piseddu I, Cadilha BL, Ledderose S, Zwilling J, Ohmura S, Anz D, Künkele A, Klauschen F, Grünewald TGP*, Knott MML*. Neomorphic DNA-binding enables tumor-specific therapeutic gene expression in fusion-addicted childhood sarcoma. Mol Cancer 2022;21(1):199.
  • Kontermann RE, Ungerechts G, Nettelbeck DM. Viro-antibody therapy: engineering oncolytic viruses for genetic delivery of diverse antibody-based biotherapeutics. mAbs 2021;13: 1982447.
  • Dorer DE, Nettelbeck DM. Targeting cancer by transcriptional control in cancer gene therapy and viral oncolysis. Adv Drug Deliv Rev 2009; 61(7-8):554-71.

Funding
European Union
World Wide Cancer, project grant

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