Construction and Drug Screening of 3D Co-culture System Using Extrahepatic Cholangiocarcinoma Organoids and Tumor-associated Macrophages

Abstract Background: Tumor-associated macrophages (TAMs) play a key role in cholangiocarcinoma, but research has been hindered by the lack of highly reductive tumor models. Organoids are a type of three-dimensional (3D) cell-culture technology derived from tumor stem cells in vitro. Although organoids are appropriate experimental models for tumor research, they cannot reflect the crosstalk that occurs between cancer cells and TAMs in the tumor microenvironment (TME). Methods: We successfully established a tumor model by co-culturing organoids and TAMs from 6 cases of primary extrahepatic cholangiocarcinoma (eCCA) through Transwell culture systems, and we explored the interactions between cells. Result: Our comprehensive analysis and comparison of histopathology, genomics, and multiomics outcomes confirmed that this co-culture model can better capture intra- and inter-tumor heterogeneity. Drug sensitivity data in vitro revealed that gemcitabine and cisplatin are effective drugs for cholangiocarcinoma, and TAMs in the tumor microenvironment promote organoids growth and chemotherapy resistance. Conclusion: In conclusion, our organoid model of cholangiocarcinoma co-cultured with TAMs highly simulates source specimens and is a promising preclinical tumor model.