IL-33/ST2 Signaling and its Correlation with Macrophage Heterogeneity and Clinicopathologic Features in Human Intrahepatic Cholangiocarcinoma.

BACKGROUND

IL-33/ST2 signaling plays crucial roles in the development and progression of various human malignancies. However, its significance in intrahepatic cholangiocarcinoma (ICC) still remains unclear.

OBJECTIVE

This study aimed to investigate the expression of IL-33/ST2 signaling and its correlations with macrophage heterogeneity and ICC patients' clinicopathologic features.

METHODS

The expression of different phenotype macrophage markers and IL-33/ST2 signalingrelated markers was detected. The correlation between L-33/ST2 signaling and different phenotype macrophage markers as well as ICC patients' clinicopathologic data was evaluated.

RESULTS

Massive heterogeneous cancer cells and PAS-positive cells were observed in tumor tissues. CD68-positive cells accumulated in tumor tissues and expression of both M1 phenotype markers and M2 phenotype macrophage markers was higher in tumor samples than para-carcinoma samples. However, M2 phenotype macrophages represented the dominant macrophage population in ICC tissues. Plasma levels of IL-33, ST2, and MIF were evidently enhanced in ICC patients compared to healthy controls. IL-33/ST2 signaling-related markers exhibited a massive increase in tumor samples than para-carcinoma samples. IL-33 and ST2 expression in ICC tissues was positively associated with M1 and M2 phenotype macrophages. Plasma levels of IL-33, ST2, and MIF were correlated with the diameter of tumor lesions, lymph node metastasis, TNM stage, and tumor differentiation degree. Multivariate analysis demonstrated IL-33 expression to exhibit a correlation with the diameter of tumor lesions, lymph node metastasis, and TNM stage. Additionally, there was a relationship observed between ST2, MIF expression, and diameter of tumor lesions plus TNM stage.

CONCLUSION

IL-33/ST2 signaling exhibited a positive relationship with macrophage heterogeneity in ICC tissues, and upregulated levels of IL-33, ST2, and MIF were associated with aggressive clinicopathologic characteristics. These findings may provide promising diagnostic biomarkers and potential therapeutic strategies for ICC patients targeting IL-33/ST2 signaling.