Temporal and Spatial Dynamics of Hepatic Stellate Cell Activation in Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is characterized by its highly desmoplastic stroma mainly composed of myofibroblasts derived from activated hepatic stellate cells (HSCs). The role of HSCs in ICC development remains controversial. We aim to dissect the function of HSCs in ICC development.An orthotopic allograft of metastatic ICC was generated to track the activation of intra- and peri-tumoral HSCs (itHSCs and ptHSCs, respectively). Multiple coculture systems were established to assess the impact of itHSCs and ptHSCs on ICC development. RNA-seq transcriptomic profiling was performed to examine ICC-induced liver host response.Activated itHSCs and ptHSCs are found in ICC patient tumors and surrounding liver. Tracking HSC in the ICC allograft model reveals HSC activation starting at the tumor border and extending into both tumor core and peritumoral liver when tumor progresses. In vitro coculture assays identify a surprising suppressive effect of ptHSCs on ICC cell growth in contrast to the pro-proliferative effect of itHSCs. Prolonged ICC-ptHSC interaction elicits tumor cell dissemination in vitro. ICC dissemination in vivo temporally and spatially coincides with further HSC activation in the liver which shows a protective effect on tumor-induced hepatocyte death. ICC-ptHSC interaction induces Vcam1 upregulation in the tumor cells which fine tunes the balance between ICC growth and dissemination. Transcriptomic analysis of the ICC allograft model reveals broad peritumoral changes in liver metabolism, oncogenic activation, and immune response.In this study, we demonstrate that HSCs are activated during ICC development in a temporal- and spatial-specific manner and play a dynamic role in the intricate ICC-liver interaction.