CAR T Cells vs Cancer: An Insight into Immunotherapy

"The cell, as it were, is experimenting with physiology, passing molecules in and out, making chemicals and destroying chemicals. It is the laboratory of reactions that enables life" - Siddhartha Mukherjee in The Song of the Cell

Over the years, the field of cancer therapeutics has garnered significant public interest and attention. While chemotherapy and radiotherapy remain among the most well known therapeutic routes for cancer, other emerging areas include immunotherapies, gene therapies, peptide drugs, protein and mRNA-based cancer vaccines [1, 2]. Among these newer facets of oncology research, immunotherapies pique widespread curiosity among scientists because it involves turning immune cells into individualized therapies against cancer development.

The potential of immunotherapies to suppress tumor growth and development has been explored

across a spectrum of cancer types. This ranges from hematological malignancies (blood cancers) and gastrointestinal cancers to skin cancers, reproductive cancers etc. While there are various types of immunotherapies, certain types like CAR T cell therapy, NK cell therapy, and ICi (Immune checkpoint inhibitors), to name a few, have been gaining traction for its therapeutic scope in recent years [3]

However, for the purposes of this blog post, I will be focusing on CAR T Cell Therapy and its applications in the world of oncology. T cells, a major immune cell type involved in the adaptive immune system, mainly take part in immune responses against pathogens [4]. To elicit an immune response against cancer cells, T cells are first isolated from the individual's blood [5]. Then, these T cells are genetically engineered to possess CARs (chimeric antigen receptors) in laboratories [5]. CARs are responsible for enhancing the T cell ability to bind to specific antigens on the cancer cell surface, once they are infused back into the patient's bloodstream after undergoing a large-scale expansion [5]. In the case of blood cancers, CAR T Cell therapy has made significant progress as a therapeutic route for both adults and children. CAR T cell therapy has been approved by the FDA for certain types of leukemia, lymphoma and myeloma [6].

Although the premise of CAR T cell therapy remains compelling, there are certain drawbacks and sideeffects associated with such cellular immunotherapy. Some of the limitations include antigen binding on healthy cells (instead of cancer cells), CAR T cells missing an attack on a cancer cell without desired antigen (antigen escape), and the immunosuppresive microenviroment created by tumors [7]. The immunosuppresive microenvironment limit CAR T cell access towards the tumor and faciliate CAR T cell dysfunctioning via immune cell signaling [5,7]. General side-effects from CAR T cell therapy includes wide-scale B cell (antibody producing immune cell) death, neurological issues, and cytokine release syndrome (CRS) [5]. Cytokine release syndrome entails a massive amount of inflammation which ultimately contributes to organ damage [8].

Ongoing efforts to universalize CAR T cell therapies, specifically in the context of blood cancers and creating CAR T cell therapies that do not exhibit too many side-effects portay the future directions of research surrounding this particular type of cellular immunotherapy [5]. Intriguingly, there is still not much we know about CAR T cell therapy and its scope in cancers aside from hematological malignancies. This, in particular, leaves me excited for the developments in CAR T cell therapy research and how it could potentially become a more well-known type of cancer immunotherapy!

References

1. Liu, B., Zhou, H., Tan, L. et al. Exploring treatment options in cancer: tumor treatment strategies. Sig Transduct Target Ther 9, 175 (2024). https://doi.org/10.1038/s41392-024-01856-7

2. Pancholi, Neha J. “What Is a Cancer Vaccine? .” American Association for Cancer Research (AACR), 23 Jan. 2025, www.aacr.org/blog/2024/06/28/what-is-a-cancer-vaccine/.

3. Shuzhen Tan, Dongpei Li, Xiao Zhu,Cancer immunotherapy: Pros, cons and beyond,

   Biomedicine & Pharmacotherapy,Volume 124,2020,109821,ISSN 0753-3322,

   https://doi.org/10.1016/j.biopha.2020.109821.

4. Sun, L., Su, Y., Jiao, A. et al. T cells in health and disease. Sig Transduct Target Ther 8, 235 (2023). https://doi.org/10.1038/s41392-023-01471-y

5. “Car T Cells: Engineering Immune Cells to Treat Cancer.” CAR T Cells: Engineering Immune Cells to Treat Cancer - NCI, www.cancer.gov/about-cancer/treatment/research/car-t-cells. Accessed 14 Sept. 2025.

6. Brudno, Jennifer N et al. “CAR T Cells and T-Cell Therapies for Cancer: A Translational Science Review.” JAMA vol. 332,22 (2024): 1924-1935. doi:10.1001/jama.2024.19462

7. Sterner, R.C., Sterner, R.M. CAR-T cell therapy: current limitations and potential strategies. Blood Cancer J. 11, 69 (2021). https://doi.org/10.1038/s41408-021-00459-7

8. Shimabukuro-Vornhagen, Alexander et al. “Cytokine release syndrome.” Journal for immunotherapy of cancer vol. 6,1 56. 15 Jun. 2018, doi:10.1186/s40425-018-0343-9