Engineered CAR T cells targeting mesothelin by piggyBac transposon system for the treatment of pancreatic cancer

Patients with pancreatic cancer have a poor prognosis largely due to the poor efficacy of the available treatment modalities. In this study, we engineered mesothelin-targeting chimeric antigen receptor T cells (mesoCAR T) using the piggyBac transposon based plasmid electroporation technique for specific targeting of pancreatic cancer cells expressing mesothelin. In vitro, mesoCAR T cells exhibited rapid and robust killing effect against ASPC1 cells with high expression levels of mesothelin with high production of IFN-γ; the cytotoxic effect on PANC1 cells with low expressions of mesothelin was relatively attenuated. In the ASPC1 xenograft mice model, mesoCAR T cells significantly suppressed the tumor growth accompanied with higher-level IFN-γ secretion as compared to control T cells. Besides, more mesoCAR T cells differentiated into memory T cells after tumor remission, whilst causing minimal lesions in major organs. Our study suggests promising efficacy of piggyBac transposon-based mesoCAR T cell therapy for pancreatic cancer, which is a potential candidate for clinical translation.