• Cancer Immunotherapy using CRISPR/Cas9 system; a powerful tool
  • Mohsen Yaghoubi,1 Moein Iranmanesh,2,*
    1. Biology Research Center, Faculty of Basic Sciences, Imam Hossein University, Tehran, Iran
    2. Biology Research Center, Faculty of Basic Sciences, Imam Hossein University, Tehran, Iran


  • Introduction: The emergence of CRISPR-Cas9 genome editing tool has revolutionized the field of biotechnology, offering unparalleled potential in various disciplines, including cancer immunotherapy. This article provides an overview of how CRISPR-Cas9 is being utilized to enhance the effectiveness of cancer immunotherapy. Cancer immunotherapy aims to harness the body's immune system to recognize and eliminate cancer cells. However, numerous challenges, including tumor heterogeneity and immune evasion mechanisms adopted by cancer cells, limit the efficacy of current immunotherapeutic approaches. CRISPR-Cas9 presents a powerful tool to overcome these challenges by enabling precise and targeted modifications in the genome of immune cells and tumor cells.
  • Methods: Engineering Immune Cells using CRISPR-Cas9 One of the key applications of CRISPR-Cas9 in cancer immunotherapy involves editing immune cells, such as T cells, to enhance their anti-tumor activity. By manipulating genes encoding immune checkpoints, co-stimulatory molecules, or chimeric antigen receptors (CARs), scientists can optimize T cell function and response against cancer cells. This approach has shown promising results, with engineered T cells exhibiting enhanced tumor recognition and killing abilities in preclinical and clinical studies. This approach has also been used to modify immune cells to target solid tumors, which are often resistant to traditional treatments. CART cell therapy involves genetically modifying a patient's T-cells to express a chimeric antigen receptor (CAR) that can recognize and bind to specific proteins on cancer cells. The CAR is composed of an extracellular domain that recognizes the target protein, a transmembrane domain, and an intracellular signaling domain that activates the T-cell when the CAR binds to the target protein. Once the T-cells are modified, they are expanded in the laboratory and infused back into the patient. The CART cells then migrate to the site of the cancer and bind to the target protein on the cancer cells, leading to their destruction. Modifying Tumor Cells with CRISPR-Cas9 Another application of CRISPR-Cas9 in cancer immunotherapy is the modification of cancer cells themselves. Through gene editing, researchers can disrupt genes responsible for immune evasion mechanisms or induce the expression of immune-stimulatory molecules on tumor cells. This modification induces tumor vulnerability to immune attack and stimulates anti-tumor immune responses, leading to improved therapeutic outcomes. Targeting Key Genes Involved in Immune Regulation CRISPR-Cas9 can be utilized to target genes involved in immune regulation, such as ytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein 1 (PD-1) or Transforming growth factor beta (TGF-β). By disrupting these genes, the immunosuppressive signals in the tumor microenvironment can be attenuated, leading to enhanced anti-tumor immune responses.
  • Results: Development of personalized cancer vaccines with CRISPR-Cas9 technology Moreover, CRISPR-Cas9 technology is facilitating the development of personalized cancer vaccines. By introducing tumor-specific antigens into immune cells, scientists can boost the immune system's ability to recognize and eliminate cancer cells. CRISPR-Cas9 allows precise editing of antigens, ensuring optimal immunogenicity and safety of personalized vaccines. Challenges and Future Directions Despite its immense potential, challenges and ethical considerations surround the application of CRISPR-Cas9 in cancer immunotherapy. Off-target effects and long-term safety concerns require careful monitoring and testing. To reduce off-target cleavage, the guide RNA should be designed with high sequence homology to the target gene. In addition, Cas9-crRNA should be delivered by viral vector or plasmid, which can minimize the potential mutations caused in guide RNA synthesis. Recently, engineered or natural Cas9 ortholog proteins have been developed to improve its specificity and efficiency. Additionally, Researchers must ensure that the modified immune cells do not cause harm to the patient, and there is also a risk of unintended consequences from modifying genes. Recently, Professor Zhang and colleagues observed a system similar to CRISPR in eukaryotic cells, which was named OMEGA. The most interesting point after this discovery will be that maybe in the near future for human genetic manipulation, we only need to deliver the sgRNA sequence to the target cell and the rest of the protein components will be supplied from within the cell itself.
  • Conclusion: In conclusion, the application of CRISPR-Cas9 genome editing tool in cancer immunotherapy holds immense promise for revolutionizing cancer treatment. Through precise genetic modifications of immune cells and cancer cells, the efficacy and specificity of current immunotherapeutic approaches can be improved. Continued research and innovation in this field will contribute to the development of safe and effective therapies, bringing us closer to defeating cancer.
  • Keywords: CRISPR/Cas9, Genome Editing, Cancer Immunotherapy, Cancer Treatment, Immune Response