Establishment and characterization of CHC-X1: the third human combined hepatocellular–cholangiocarcinoma cell line

Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) represents an uncommon variant of primary liver cancer. In recent years, its incidence rate has increased. Thus, it is essential to perform comprehensive investigations into cHCC-CCA to develop suitable treatment strategies. So far, only two cell lines (CLs) of this cancer type have been reported. More cHCC-CCA CLs need to be established for research purposes. In this investigation, we developed a stable cHCC-CCA CL, named CHC-X1. STR analysis confirmed that CHC-X1 is a new human cHCC-CCA CL. CHC-X1 is a complex karyotype. Its population doubling time is 50.72 h. Under suspended conditions, CHC-X1 can form tumor spheres and organoids in Matrigel. These cells exhibit sensitivity to paclitaxel while demonstrating resistance against oxaliplatin, gemcitabine, and 5-FU. After inoculation into NXG mice, CHC-X1 can quickly form subcutaneous transplant tumors, exhibiting a tumor establishment rate of 67%. Immunohistochemical staining showed that CHC-X1 is a tumor CL with both liver cell differentiation and bile duct cell differentiation characteristics. It may function as a useful model for identifying the origins of cHCC-CCA and the advancement of potential treatments.