Periostin (POSTN) secreted by intrahepatic cholangiocarcinoma stem cells (ICSCs) serves important roles in promoting tumor progression. The present study aimed to investigate POSTN-recruited tumor-associated macrophages (TAMs) in intrahepatic cholangiocarcinoma (ICC). A total of 50 cases were used to investigate the distribution of ICSCs and TAMs in ICC. HCCC-9810 cells were sorted by cluster of differentiation (CD)44, the expression of POSTN of CD44+ (cancer stem cells) and CD44- cells (non-cancer stem cells), and medium were evaluated by western blot analysis. HCCC-9810 cells and THP-1 macrophages were used to detect the effects of POSTN on recruiting TAMs in vitro. The present study revealed that CD44+ cells in ICC tissues and the HCCC-9810 cell line were associated with high POSTN secretion levels. Furthermore, POSTN was associated with TAM density in primary ICC tissues. Additionally, POSTN increased the migration of TAMs derived from THP-1 cells. These findings suggested that POSTN secreted by ICSCs may serve important functions in TAM recruitment, and it may be a potential curative strategy to target the tumor microenvironment in ICC.
Keywords: cancer stem cells; intrahepatic cholangiocarcinoma; migration; periostin; tumor-associated macrophages.