The tricks for fighting against cancer using CAR NK cells: A review

Natural killer (NK) cells seem to be the most common innate lymphocyte subtypes, and they're known for their ability to guide anti-tumor and anti-viral responses, making them potentially therapeutic. Since NK cells lack polymorphic clonotypic receptors, they must rely on inhibitory receptors to develop, mature, and distinguish between "self" and "non-self." In the clinic, genetically engineered immune cells expressing a chimeric antigen receptor (CAR) that consists of an extracellular antigen recognizing domain connected to an intracellular signaling domain have gained interest. The U.S. food and drug administration (FDA) approved two CAR-T cells, anti-CD19 CARs, for the treatment of relapsed/refractory B-cell acute lymphoblastic leukemia (B-ALL) and diffuse large B-cell lymphoma (DLBCL). Nevertheless, CAR-T cell therapy is linked to a series of negative side effects, including fatal cytokine release syndrome (CRS) and tumor lysis syndrome (TLS), as well as a lack of regulatory control. CAR-transduced NK cells (CAR-NK) are thought to have many benefits, including clinical safety, the mechanisms by which they identify cancerous cells, and their abundance in clinical specimens, according to a growing number of studies. In pre-clinical and clinical trials, human primary NK cells and the NK-92 cell line were effectively transduced to express CARs against hematological cancers and solid tumors. Here, it is tried to summarize the development of CAR-NK cells, challenges and coping strategies, as well as managing the challenges and obstacles related to its protection, which promises to eliminate the shortcomings of conventional CARs.