Fig. 4

Irbesartan overcomes gemcitabine resistance of PDAC in a c-Jun dependent manner. A RNA-sequencing was performed on PDO1# line treated with vehicle and irbesartan and the DEGs were represented as volcano plot. B-E The expression of c-Jun in organoids treated with vehicle and irbesartan was evaluated by Q-PCR (B), western blot (C) and immunofluorescence staining (D-E). F The expression of c-Jun in PDOX of mice in vivo was determined by multiplex IHC staining. G The promoter activity of c-Jun in PDO1# after treating with irbesartan (1 μM, 72 h) was detected by dual luciferase assay. H-I PDO1#-scramble/c-Jun-KO lines were treated with vehicle, GEM, irbesartan and GEM plus irbesartan for 72 h (irbesartan 1 μM, GEM 0.8 μM), followed by monitoring organoid apoptosis by real-time caspase3/7 probe imaging (H) and evaluating organoid proliferation by Ki-67 immunofluorescence staining (I). J-K PDO7#/PDO10# were treated with vehicle, GEM, irbesartan and GEM plus irbesartan for 72 h (irbesartan 1 μM, GEM 0.8 μM), followed by monitoring organoid apoptosis by real-time caspase3/7 probe imaging (J) and evaluating organoid proliferation by Ki-67 immunofluorescence staining (K). L The experimental setup for in vivo PDOX assay. M Representative pancreatic tumor images per group at the experimental ending were shown (left) and tumor weight was determined (right). N The apoptotic level of PDOX tumor in mice were evaluated by TUNEL staining. O Kaplan–Meier survival curves with log-rank test were used to analyze the effects after drug treatment in another cohort (n = 6). All experiments were repeated three times independently. Paired Student’s t-test were used for in vitro experiments. Un-paired Student’s t-test were used for in vivo experiments