Feasibility assessment of using cRISPR-Cas9 to improve the infiltration of CAR-T cells in solid tumors

Abstract. Chimeric antigen receptor T-cell immunotherapy (CAR-T) has been developing for decades, CAR-T is playing an increasingly important role in tumor treatment. However, because fibroblasts (CAFs) in solid tumors secrete proteins and glycans to form ECM, CAR-T is faced with the challenge of improving tumor invasion. To this end, a new scheme was put forth to alter CAR T cells such that they release heparinase (HPSE) to break down heparan sulfate proteoglycan (HSPG), which is covered on the outermost layer of the cancerous cells by CAF and released. In order to solve the above problems, CRISPR-Cas9 was proposed to modify CAR T to enhance the secretion of HPSE. Although this method has the advantage of broad spectrum, it still has certain defects. The matrix characteristics of different solid tumors and the subpopulations and regulatory mechanisms of HPSE need to be further studied. The off-target effects of CRISPR-Cas9 gene editing technology and the high cost and time-consuming problems of flow cytometry also limit its application. It is anticipated to enhance cell infiltration in solid tumors, boost CAR-T therapy's effectiveness in treating solid tumors, and advance the field of CAR-T therapy.