1. Department of Medical Melanoma and Sarcoma, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, 510060, China
2. Key Laboratory of Medical Reprogramming Technology, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, 518039, China
3. Department of Urology, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Carson International Cancer Center, Shenzhen University School of Medicine, Shenzhen 518039, China
4. Guangdong Key Laboratory of Systems Biology and Synthetic Biology for Urogenital Tumors, Shenzhen 518035, China
Chimeric antigen receptors (CARs) are engineered synthetic receptors that redirect and reprogram T cells to tumor surface antigens for subsequent eradication. The unprecedented efficacy of CD19-CAR T cells against B-cell malignancies has inspired oncologists to extend these efforts for the treatment of solid tumors. However, limited success has been achieved so far, partially due to some of the formidable challenges, e.g. suppression of full activation, inhibition of T cell localization, lacking of ideal targets, inefficient trafficking and infiltration, immunosuppression of microenvironment, and the probability of off targets and associated side effects. Significant progresses have being made recently. Thus, an updated summary is urgently needed. Here in this review, we discuss the advantages and some of the key hurdles encountered by CAR T cell therapy in solid tumors as well as the strategies adopted to improve therapeutic outcomes of this approach. Continuing efforts to increase therapeutic potential and decrease the adverse effects of adaptive cell transfer are suggested as well.
Keywords: CAR T cell therapy, Solid cancer, Immunosuppression, Anti-tumor responses