Establishment and characterization of DPC-X4: a novel mixed-type ampullary cancer cell line.

Abstract

Mixed-type ampullary cancer is a distinct subtype of ampullary cancer that manifests a merging of the biological characteristics of both intestinal and pancreaticobiliary subtypes. The absence of established cell lines specific to this subtype has resulted in a concomitant scarcity of research on its tumorigenic mechanisms and the development of novel therapeutic modalities. The present study achieved the successful establishment of a novel mixed-type ampullary cancer cell line, designated DPC-X4 through primary culture techniques. Subsequent analyses pertaining to phenotypic characteristics, molecular profiling, biomarker identification, and histological features validated the DPC-X4 cell line as a potent model for delineating the pathogenesis of mixed-type ampullary cancer and facilitating the development of new pharmacological agents. This newly established cell line was subjected to continuous cultivation for 1year, with stable passaging for over 50 generations. Notably, the DPC-X4 cell line manifested typical morphological features associated with epithelial tumors. Furthermore, the population doubling time for the DPC-X4 cell line was determined at 70h. Short tandem repeat (STR) analysis confirmed that the DPC-X4 cell line exhibited a high genetic concordance with the primary tumor from the patient. Karyotypic profiling indicated an abnormal sub-triploid karyotype, with representative karyotypes of 57, XXY inv (9), 14p + , 15p + , der (17), + mar. The DPC-X4 cell line demonstrated a high capacity for efficient organoid formation under suspension culture conditions. In addition, the subcutaneous inoculation of DPC-X4 cells into NXG mice led to the formation of xenografted tumors. The results of drug sensitivity testing indicated that DPC-X4 cells were sensitive to paclitaxel and resistant to oxaliplatin, 5-fluorouracil, and gemcitabine. Immunohistochemistry revealed positive expression of CK7, CK19, and CK20 in DPC-X4 cells, while CDX2 demonstrated negative expression. In addition, positive expression of E-cadherin and vimentin was identified in DPC-X4 cells, with a proliferation index indicated by Ki-67 at 70%. The findings of our study establish DPC-X4 as a novel mixed-type ampullary cancer cell line, which can serve as a potential experimental model for exploring the pathogenesis of ampullary cancer and the development of therapeutic drugs.