Fig. 2. Paracrine IL8 was essential for CAF^R-induced oxaliplatin resistance in tumor cells.

A Cytokine antibody array of CAF^S1-CM or CAF^R1-CM. CAF^R1-CM with different neutralizing antibodies was used to culture Panc-1 (B) and MIAPaCa-2 (C) cells for 3 days. After 48 h of oxaliplatin exposure, cell viability was measured by CCK8. D Panc-1 and MIAPaCa-2 cells were cultured with different concentrations of human recombinant IL8 for 3 days and subsequently treated with oxaliplatin for 48 h. Cell viability was measured by CCK8. E ELISA analysis of the IL-8 levels in CAF^S-CM and CAF^R-CM of four different chemosensitive and chemoresistant CAF cell lines. Panc-1 and MIAPaCa-2 cells were cultured with IL8 (100 ng/ml) or CAF^R1-CM with an anti-IL8 neutralizing antibody (250 ng/ml) for 3 days. Colony formation assay (F, G) and flow cytometry apoptosis analysis (H, I) were performed to evaluate the chemoresistance of pancreatic cancer cells in each group. The results are presented as the mean ± SD of three technical replicates. *P < 0.05; **P < 0.01; ***P < 0.001; ns no significance.