Fig. 4

Transforming growth factor (TGF)-β-mediated PAR1 upregulation enhances pancreatic ductal adenocarcinoma (PDAC) cell responsiveness to PAR1CAR-T-cell-specific suppression. A Human PDAC cell lines (HPAF-II, CFPAC-1, and MIA PaCa-2) were exposed to TGF-β (18 ng/mL), and cells were collected at indicated times over 48 h. PAR1 expression was measured by flow cytometry. Results revealed original and enhanced levels of PAR1 by quantifying the mean fluorescent intensity (MFI) (left panel), expression fold-changes (right panel), and cell fold-changes (middle panel) over incubation times. B Standard 24-h cytotoxic activities of PAR1CAR-T cells toward tumor cells were measured using MTT assays with increasing effector/tumor (E/T) ratios of 0, 0.1, 1, 5, 10, and 20 against HPAF-II, CFPAC-1, and MIA PaCa-2 cells following 18 ng/mL TGF-β stimulation (18 ng/mL) for 48 h. Cytotoxic activities were compared to those of non-transduced CD3⁺ T-cell-treated cells, and mock-transduced T-cell-treated cells served as control PAR1CAR-T cells (n > 3; * p < 0.05 and *** p < 0.001, respectively). Results are the mean ± SD of three independent experiments