Tu Jianfei, Chen Li, Ying Xihui, Ji Jiansong

Department of Radiology and interventional radiology, Lishui Central Hospital

Objective:Interleukin (IL)-17 is expressed in the tumor micro-environment where it appears to contribute to tumor development. In hepatocellular carcinoma (HCC) studies, IL-17 has been associated with poor prognosis. However, the source of the increased tumor-infiltrating IL-17 in HCC and prognostic valve remain poorly understood. Method: 59 HCC patients were enrolled in this study, immunofluorescence double stain was used to evaluate the colocalization of CD3+T cells, CD4+T cells, CD56+NK cells, CD20+B cells, CD68+Macrophages, and mast cell tryptase+mast cells (MCT+mast cells) with IL-17. The prognostic effect of groups with high and low MCT numbers was evaluated by Kaplan-Meier analysis and Cox regression model. Result: MCT+mast cells, but not other cells, were the predominant IL-17-producing cell type. In HCC patients, immunofluorescence double stain showed a positive correlation between the number of MCT+mast cells and microvessels (MCVs) and the majority of vascular endothelial cells expressing IL-17 receptor (IL-17R). Overall survival analysis revealed that the increasing intratumoral infiltrated MCT+mast cells were significantly associated with a poor prognosis. Conclusion: These findings indicated the major source of IL-17 in HCC were MCT+mast cells and these cells infiltration may promote tumor progression by enhancing angiogenesis through the axis of IL-17/IL-17R. Increased IL-17-positive MCT+mast cells was associated a poor prognosis, indicating therapy targeting MCT+mast cells might be an effective strategy in controlling intratumor IL- 17 infiltration and MCVs.

Key Words: Hepatocellular carcinoma  Mast cells  Interleukin 1