Establishment of pancreatic cancer cell lines with endoscopic ultrasound‐guided biopsy via conditionally reprogrammed cell culture

Recent studies have identified the mutational landscape of pancreatic cancer and suggested tumor‐specific subtypes. However, the major hurdle against personalized treatment is the difficulty to obtain sufficient cancer tissues from most inoperable cases. We investigated whether patient‐derived conditionally reprogrammed cells (CRCs) can be constructed using a small piece of tumor tissue using endoscopic ultrasound (EUS)‐guided fine needle biopsy (FNB). Thirty patients with pancreatic solid mass (mean size, 34.6 mm) were enrolled prospectively. Among 22 patients who were diagnosed with pancreatic ductal adenocarcinoma, we established patient‐derived pancreatic cancer cell lines from eight patients (36.4%). Immunofluorescence colony staining for CRCs showed that the cytoplasm of cancer cells was clearly stained with anti‐cytokeratin 19 monoclonal antibody. In the soft agar colony formation assay, CRCs formed colonies compared with the negative control by day 15. In vivo, implanted CRCs showed tumor engraftment and hematoxylin and eosin staining showed pancreatic cancer ductal structure. All established CRCs showed a KRAS mutation. In conclusion, we established patient‐derived pancreatic cancer cell lines with a small tumor tissue obtained by EUS‐FNB. With in vitro drug sensitivity and genomic studies, established patient‐derived cell lines can be used in identification of new targets for diagnosis and treatment of pancreatic cancer.