Establishment and characterization of a new Chinese extrahepatic cholangiocarcinoma cell line, EBC-X1

Cholangiocarcinoma (CCA) is a highly heterogeneous primary malignant tumor of the biliary tract. Intrahepatic and extrahepatic cholangiocytes originate from different sources, resulting in significant clinical, epidemiological, molecular, and genetic heterogeneity. Globally, the incidence and mortality rates of CCA are generally increasing, highlighting the need for more foundational research to support advances in clinical diagnosis and treatment. Tumor cell lines remain a crucial tool for unraveling the molecular mechanisms underlying tumor development and for the development of novel therapeutic strategies. The existing CCA cell lines are insufficient to meet research demands, underscoring the urgent need to establish new CCA cell lines. In this study, we successfully established a novel human CCA cell line, designated EBC-X1, derived from a Chinese patient. It exhibits robust proliferative capacity and was successfully passaged for more than 40 generations. STR analysis confirmed that EBC-X1 is a distinct human-derived CCA cell line. The population doubling time was 64.5 h. Karyotypic analysis revealed that EBC-X1 cells exhibit complex karyotypes, with 91% being sub-diploid and 9% being sub-triploid. The representative karyotype is 35, X, der(4), del(5)(q35), der(8), inv(9), der(11), rob(13;15). Upon inoculation into NXG mice, subcutaneous transplant tumors were efficiently formed. EBC-X1 is resistant to paclitaxel, fluorouracil, and oxaliplatin but sensitive to gemcitabine. This model holds significant potential for advancing our understanding of the biological characteristics and molecular mechanisms of distal CCA, as well as for facilitating drug development efforts.