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von Soosten L, Haar J, Frehtman V, Holderbach S, Belzen JUZ, Jendrusch M, Okonechnikov K, Pfister SM, Grimm D, Leuchs B, Jones D, Kutscher LM, Zuckermann M. THER-01. Precision brain tumor therapy by AAV-mediated oncogene editing. Neuro Oncol 2022. [PMCID: PMC9165130 DOI: 10.1093/neuonc/noac079.695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Pediatric high-grade glioma is a heterogeneous group of highly malignant tumors of the central nervous system, with a median overall survival of less than two years after diagnosis, demanding novel treatment options. One innovative approach is gene therapy, which has so far been hampered for cancer treatment owing to the lack of a system targeting tumor cells specifically. To overcome this limitation, we established a novel strategy for gene therapy, combining tumor cell-specific adeno-associated virus (AAV) variants with oncogene-specific CRISPR-Cas nucleases. We screened 177 different Cas9/gRNA combinations targeting the genes encoding H3K27M or BRAFV600E, and identified highly specific nucleases that edited the oncogenic allele but left the respective WT loci intact, which we validated by PCR amplicon sequencing. Next, we intravenously injected an AAV library engineered to encode its own capsid DNA into mice harboring patient-derived xenograft tumors driven by H3K27M or BRAFV600E. After 21 days, we resected neoplasms and separated mCherry-labeled tumor cells from normal surrounding cells by fluorescence-activated cell sorting. Using the DNA from tumor cells as template, we generated a second AAV library, which was utilized in another round of in vivo selection. At the end of each screen, DNA from tumor cells, surrounding cells, and control tissues (liver and spleen) was analyzed by amplicon sequencing. Strikingly, we identified multiple AAV variants that were highly and recurrently enriched in the analyzed tumor tissues. We are currently validating these variants by intravenously injecting selected, GFP-encoding AAVs to tumor-bearing mice and by subsequently analyzing their distribution throughout the aforementioned tissues. We will combine oncogene-specific nucleases with these validated AAV variants and analyze their anti-tumoral efficacy in a preclinical setting. Furthermore, we plan to adapt this approach to allografted mice, evaluating its feasibility and efficacy in syngeneic models.
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Affiliation(s)
- Laura von Soosten
- Division of Pediatric Glioma Research, Hopp Children’s Cancer Center Heidelberg (KiTZ) and German Cancer Research Center (DKFZ) , Heidelberg , Germany
- Faculty of Biosciences, Heidelberg University , Heidelberg , Germany
| | - Janina Haar
- Department of Infectious Diseases/Virology, Medical Faculty, University of Heidelberg , BioQuant, Heidelberg , Germany
| | - Veronika Frehtman
- Tumor Virology, German Cancer Research Center (DKFZ) , Heidelberg , Germany
| | - Stefan Holderbach
- Department of Infectious Diseases/Virology, Medical Faculty, University of Heidelberg , BioQuant, Heidelberg , Germany
- Synthetic Biology Group, BioQuant Center, University of Heidelberg , Heidelberg , Germany
| | - Julius Upmeier zu Belzen
- Synthetic Biology Group, BioQuant Center, University of Heidelberg , Heidelberg , Germany
- Digital Health Center, Berlin Institute of Health (BIH) and Charité University Medicine , Berlin , Germany
| | - Michael Jendrusch
- Synthetic Biology Group, BioQuant Center, University of Heidelberg , Heidelberg , Germany
- European Molecular Biology Laboratory (EMBL) , Heidelberg , Germany
| | - Konstantin Okonechnikov
- Division of Pediatric Neurooncology, Hopp Children’s Cancer Center Heidelberg (KiTZ) and German Cancer Consortium (DKTK) and German Cancer Research Center (DKFZ) , Heidelberg , Germany
| | - Stefan M Pfister
- Division of Pediatric Neurooncology, Hopp Children’s Cancer Center Heidelberg (KiTZ) and German Cancer Consortium (DKTK) and German Cancer Research Center (DKFZ) , Heidelberg , Germany
- Department of Pediatric Oncology, Hematology, Immunology and Pulmonology, Heidelberg University Hospital , Heidelberg , Germany
| | - Dirk Grimm
- Department of Infectious Diseases/Virology, Medical Faculty, University of Heidelberg , BioQuant, Heidelberg , Germany
- German Center for Infection Research (DZIF) and German Center for Cardiovascular Research (DZHK) , Heidelberg , Germany
| | - Barbara Leuchs
- Tumor Virology, German Cancer Research Center (DKFZ) , Heidelberg , Germany
| | - David Jones
- Division of Pediatric Glioma Research, Hopp Children’s Cancer Center Heidelberg (KiTZ) and German Cancer Research Center (DKFZ) , Heidelberg , Germany
| | - Lena M Kutscher
- JRG Developmental Origins of Pediatric Cancer, Hopp Children’s Cancer Center Heidelberg (KiTZ) and German Cancer Research Center (DKFZ) , Heidelberg , Germany
| | - Marc Zuckermann
- Division of Pediatric Glioma Research, Hopp Children’s Cancer Center Heidelberg (KiTZ) and German Cancer Research Center (DKFZ) , Heidelberg , Germany
- Division of Pediatric Neurooncology, Hopp Children’s Cancer Center Heidelberg (KiTZ) and German Cancer Consortium (DKTK) and German Cancer Research Center (DKFZ) , Heidelberg , Germany
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Bernhardt K, Haar J, Tsai MH, Poirey R, Feederle R, Delecluse HJ. A Viral microRNA Cluster Regulates the Expression of PTEN, p27 and of a bcl-2 Homolog. PLoS Pathog 2016; 12:e1005405. [PMID: 26800049 PMCID: PMC4723338 DOI: 10.1371/journal.ppat.1005405] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 12/28/2015] [Indexed: 11/19/2022] Open
Abstract
The Epstein-Barr virus (EBV) infects and transforms B-lymphocytes with high efficiency. This process requires expression of the viral latent proteins and of the 3 miR-BHRF1 microRNAs. Here we show that B-cells infected by a virus that lacks these non-coding RNAs (Δ123) grew more slowly between day 5 and day 20, relative to wild type controls. This effect could be ascribed to a reduced S phase entry combined with a moderately increased apoptosis rate. Whilst the first phenotypic trait was consistent with an enhanced PTEN expression in B-cells infected with Δ123, the second could be explained by very low BHRF1 protein and RNA levels in the same cells. Indeed, B-cells infected either by a recombinant virus that lacks the BHRF1 protein, a viral bcl-2 homolog, or by Δ123 underwent a similar degree of apoptosis, whereas knockouts of both BHRF1 microRNAs and protein proved transformation-incompetent. We find that that the miR-BHRF1-3 seed regions, and to a lesser extent those of miR-BHRF1-2 mediate these stimulatory effects. After this critical period, B-cells infected with the Δ123 mutant recovered a normal growth rate and became more resistant to provoked apoptosis. This resulted from an enhanced BHRF1 protein expression relative to cells infected with wild type viruses and correlated with decreased p27 expression, two pro-oncogenic events. The upregulation of BHRF1 can be explained by the observation that large BHRF1 mRNAs are the source of BHRF1 protein but are destroyed following BHRF1 microRNA processing, in particular of miR-BHRF1-2. The BHRF1 microRNAs are unlikely to directly target p27 but their absence may facilitate the selection of B-cells that express low levels of this protein. Thus, the BHRF1 microRNAs allowed a time-restricted expression of the BHRF1 protein to innocuously expand the virus B-cell reservoir during the first weeks post-infection without increasing long-term immune pressure. This paper explains some of the molecular mechanisms used by the Epstein-Barr virus (EBV) BHRF1 microRNA cluster to enhance transformation of B-cells after infection. We find that B-cells exposed to a virus that lacks the BHRF1 microRNAs (Δ123) undergo more apoptosis and grow more slowly between the second and the fourth weeks after infection than cells infected by an intact virus. These effects are partly mediated by the viral protein BHRF1, a homolog of the anti-apoptotic bcl-2 protein. The viral microRNAs allow abundant expression of BHRF1 early after infection and its down-regulation when transformation has been established. The first effect is mediated by the seed regions of miR-BHRF1-2 and -3, whereas the second is dependent on RNA cleavage mediated by processing of miR-BHRF1-2. Furthermore, we found that the ability of the BHRF1 microRNAs to increase cell cycle entry is related to their ability to downregulate PTEN, a crucial negative regulator of the cell cycle. We also study the consequences of the absence of the microRNAs for the infected cells. B-cells infected with Δ123 become more resistant to apoptosis and express lower levels of p27, two events that facilitate the development of genome instability. Thus, the viral microRNAs allow rapid and innocuous expansion of infected B-cells, their long-term reservoir, thereby facilitating the life-long coexistence between the virus and its host.
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Affiliation(s)
- Katharina Bernhardt
- Pathogenesis of Virus Associated Tumors, German Cancer Research Center, Heidelberg, Germany
- Inserm unit U1074, Heidelberg, Germany
| | - Janina Haar
- Pathogenesis of Virus Associated Tumors, German Cancer Research Center, Heidelberg, Germany
- Inserm unit U1074, Heidelberg, Germany
| | - Ming-Han Tsai
- Pathogenesis of Virus Associated Tumors, German Cancer Research Center, Heidelberg, Germany
- Inserm unit U1074, Heidelberg, Germany
| | - Remy Poirey
- Pathogenesis of Virus Associated Tumors, German Cancer Research Center, Heidelberg, Germany
- Inserm unit U1074, Heidelberg, Germany
| | - Regina Feederle
- Pathogenesis of Virus Associated Tumors, German Cancer Research Center, Heidelberg, Germany
- Inserm unit U1074, Heidelberg, Germany
| | - Henri-Jacques Delecluse
- Pathogenesis of Virus Associated Tumors, German Cancer Research Center, Heidelberg, Germany
- Inserm unit U1074, Heidelberg, Germany
- * E-mail:
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Haar J, Contrant M, Bernhardt K, Feederle R, Diederichs S, Pfeffer S, Delecluse HJ. The expression of a viral microRNA is regulated by clustering to allow optimal B cell transformation. Nucleic Acids Res 2015; 44:1326-41. [PMID: 26635399 PMCID: PMC4756819 DOI: 10.1093/nar/gkv1330] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 11/13/2015] [Indexed: 02/02/2023] Open
Abstract
The Epstein-Barr virus (EBV) transforms B cells by expressing latent proteins and the BHRF1 microRNA cluster. MiR-BHRF1–3, its most transforming member, belongs to the recently identified group of weakly expressed microRNAs. We show here that miR-BHRF1–3 displays an unusually low propensity to form a stem–loop structure, an effect potentiated by miR-BHRF1–3's proximity to the BHRF1 polyA site. Cloning miR-BHRF1–2 or a cellular microRNA, but not a ribozyme, 5′ of miR-BHRF1–3 markedly enhanced its expression. However, a virus carrying mutated miR-BHRF1–2 seed regions expressed miR-BHRF1–3 at normal levels and was fully transforming. Therefore, miR-BHRF1–2's role during transformation is independent of its seed regions, revealing a new microRNA function. Increasing the distance between miR-BHRF1–2 and miR-BHRF1–3 in EBV enhanced miR-BHRF1–3's expression but decreased its transforming potential. Thus, the expression of some microRNAs must be restricted to a narrow range, as achieved by placing miR-BHRF1–3 under the control of miR-BHRF1–2.
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Affiliation(s)
- Janina Haar
- Pathogenesis of Virus Associated Tumors, German Cancer Research Center, Im Neuenheimer Feld 242, 69120 Heidelberg, Germany Inserm unit U1074, Im Neuenheimer Feld 242, 69120 Heidelberg, Germany
| | - Maud Contrant
- Architecture et Réactivité de l'ARN - UPR 9002, Institut de Biologie Moléculaire et Cellulaire du CNRS, Université de Strasbourg, 15 rue René Descartes, F-67084 Strasbourg Cedex, France
| | - Katharina Bernhardt
- Pathogenesis of Virus Associated Tumors, German Cancer Research Center, Im Neuenheimer Feld 242, 69120 Heidelberg, Germany Inserm unit U1074, Im Neuenheimer Feld 242, 69120 Heidelberg, Germany
| | - Regina Feederle
- Pathogenesis of Virus Associated Tumors, German Cancer Research Center, Im Neuenheimer Feld 242, 69120 Heidelberg, Germany Inserm unit U1074, Im Neuenheimer Feld 242, 69120 Heidelberg, Germany
| | - Sven Diederichs
- Division of Cancer Research, Clinic for Thoracic Surgery, University Hospital Freiburg, Breisacher Str. 86b, 79110 Freiburg, Germany Division of RNA Biology & Cancer, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany & Institute of Pathology, University Hospital Heidelberg, Im Neuenheimer Feld 224, 69120 Heidelberg, Germany
| | - Sébastien Pfeffer
- Architecture et Réactivité de l'ARN - UPR 9002, Institut de Biologie Moléculaire et Cellulaire du CNRS, Université de Strasbourg, 15 rue René Descartes, F-67084 Strasbourg Cedex, France
| | - Henri-Jacques Delecluse
- Pathogenesis of Virus Associated Tumors, German Cancer Research Center, Im Neuenheimer Feld 242, 69120 Heidelberg, Germany Inserm unit U1074, Im Neuenheimer Feld 242, 69120 Heidelberg, Germany
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Abstract
The utilization of toehold-containing DNA strands allows for the assembly of complex nanostructures via kinetically driven hybridization reactions. Here, we have rendered this strategy ligand-dependent, resulting in small-molecule-inducible DNA nanoarchitectures.
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Affiliation(s)
- Markus Wieland
- Department of Chemistry and Konstanz Research School Chemical Biology (KoRS-CB), University of Konstanz, 78457 Konstanz, Germany
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Abstract
We assessed the impact of text messaging as the preferred method of communicating positive Chlamydia trachomatis test results in an urban sexual health clinic. Following the introduction of a text messaging service to communicate positive C trachomatis test results to patients, the time between test and treatment in 293 consecutive patients was compared with 303 historic controls. No significant difference was found in either median time to treatment for all patients (3 days in 2005; 4 days in 2007) or median time to treatment (both 7 days) for those not treated immediately. There was no significant difference in time to treatment between those using a landline or mobile phone. Mobile phone use was significantly higher in 2007. Overall, we treated more cases within 4 weeks in 2007 (98.6% cf 96%). The lack of difference in time to treatment showed the use of this technology is as effective as more traditional means of communication. The increase in cases of C trachomatis treated within 4 weeks may reflect the significant increase in mobile phone use and improved ability to contact people rather than simply the introduction of text messaging.
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Affiliation(s)
- E J Lim
- Infectious Disease/Sexual Health, Waikato Hospital, Hamilton, New Zealand
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