INTERNATIONAL CONGRESS OF
CancerGenetics
Dual CRISPR Platforms for Oncovirus Therapy: Genome Eradication with Cas9/Prime Editing and RNA
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Saghar Modaresi,1,*
1. Independent Researcher, B.Sc. in Laboratory Sciences
- Introduction: Oncoviruses, including Hepatitis B Virus (HBV) and Epstein-Barr Virus (EBV), are major contributors to chronic infections and virus-associated cancers such as hepatocellular carcinoma and nasopharyngeal carcinoma. Conventional antiviral treatments often fail to eliminate persistent viral reservoirs, including HBV covalently closed circular DNA (cccDNA) and EBV episomes, emphasizing the need for novel therapeutic strategies. CRISPR-based genome editing provides a promising approach to disrupt viral DNA, while RNA-targeting CRISPR systems enable selective silencing of viral transcripts and modulation of host immune responses. This study reviews the dual application of CRISPR/Cas9 and CRISPR/Cas13 platforms in oncovirus therapy, focusing on mechanistic insights, recent advances, and translational potential.
- Methods: We conducted a comprehensive review of recent preclinical and in vitro studies evaluating DNA-targeting Cas9 and prime editing approaches to disrupt HBV cccDNA, integrated viral DNA, and EBV episomes. RNA-targeting studies using Cas13 to silence viral transcripts, including EBNA1 in EBV and RNA genomes of RNA viruses, were included. Delivery strategies, including biomimetic extracellular vesicles, adeno-associated viral (AAV) vectors, and optimized guide RNAs, were analyzed for efficiency, specificity, and biocompatibility. Dual Cas9/Cas13 strategies, alone or in combination with immunotherapy, were also examined.
- Results: Cas9-mediated editing achieved significant reduction of HBV cccDNA (up to 96% in vitro and 52% in vivo) and efficiently disrupted EBV episomes, especially using multiplexed guide RNAs or prime editing. Cas13 effectively silenced viral transcripts, complementing Cas9 activity and enabling targeting of RNA viruses. Dual Cas9/Cas13 approaches enhanced viral suppression, increased tumor cell sensitivity to chemotherapeutics, and provided a platform for combining immunotherapy via checkpoint modulation and improved antigen presentation. Advanced delivery systems improved cellular uptake and minimized off-target effects. Remaining challenges include off-target DNA editing, collateral RNA cleavage, immune responses, and limitations in in vivo delivery.
- Conclusion: Dual CRISPR platforms integrating Cas9/prime editing with Cas13-mediated RNA silencing offer a powerful strategy for targeting persistent viral reservoirs at both genomic and transcriptomic levels. These approaches demonstrate potential for more effective antiviral therapy, prevention of virus-associated cancers, and synergy with immunotherapy. Optimization of guide RNA design, delivery methods, and safety profiles will be crucial for clinical translation, establishing CRISPR as a transformative tool in oncovirus therapy.
- Keywords: CRISPR/Cas9, CRISPR/Cas13, oncovirus, genome editing, RNA silencing, antiviral therapy
