ObjectiveTo optimize the culture method of human primary pancreatic ductal adenocarcinoma (PDAC) cells and cancer associated fibroblasts (CAFs) and investigate the effect of CAFs on the growth of primary PDAC cells in vitro and tumor formation in patient-derived xenograft (PDX) model.MethodsThe PDAC specimens were collected and primarily cultured. In order to observe the effect of CAFs on the growth of primary PDAC cells in vitro, the CAFs were co-cultured with primary PDAC cells consistently and the alone cultured primary PDAC cells served as the control. Then, these cells were injected into the shoulder blades of NOG mice in order to develop the PDX model.ResultsWhen the primary PDAC cells separated from the CAFs, the proliferation capacity of the primary PDAC decreased rapidly in the passage culture in vitro, and the most cells were terminated within 5 generations. By contrast, when the CAFs co-cultured with the primary PDAC cells, the proliferation capacity of primary PDAC cells were preserved, which could be stably transferred to at least 10 generations. The tumors of NOG mice were detected during 2–3 weeks after injecting the mixed cells (primary PDAC plus CAFs), while had no tumor formation after injecting CAFs alone. The rate of tumor was 92.9% (13 cases) in the primary PDAC plus CAFs group, which was higher than that of the CAFs alone group (64.3%, 9 cases), but there was no statistical difference because of the small sample size. The volume of tumor in the primary PDAC plus CAFs group at 2, 4, 6, and 8 weeks after the tumor cells injection was significantly larger than that in the CAFs alone group at the corresponding time point, the differences were statistically significant (P<0.01).ConclusionsThe CAFs could promote the growth of primary PDAC cells in vitro. This new method of co-culture CAFs with primary PDAC could improve the success rate of primary PDAC cells culture and improve the success rate of PDX model in NOG mice.