IL-2 Increases Tams-Derived Exosomal Mir-375 to Ameliorate Hepatocellular Carcinoma Development and Progression

Abstract Background: Interleukin-2 (IL-2) is proved to play an irreplaceable role in anti-tumor regulation in numerous experimental and clinical trials. Tumor-associated macrophages (TAMs) is able to release exosomes to promote the development and progression of hepatocellular carcinoma (HCC) as part of microenvironment.Methods: In this study, our intention is to explore the effects of the exosomes from TAMs with IL-2 treatment on HCC development.TAMs were collected and cultured from liver cancer tissues. The exosomes from the TAMs treated with IL-2 (ExoIL2-TAM) or not (ExoTAM) were identified and used to treat HCC cells. The HCC cells proliferation, apoptosis and metastasis were measured in vivo and in vitro. The changes of miR-375 in exosomes was explored to clarify whether it is reponsible to the anti-apoptotic effects of IL-2. Results: Both decrease of cell proliferation and metastasis and increase of apoptosis were observed with ExoIL2-TAM treatment compared with ExoTAM in vivo and in vitro. miR-375 was obviously abundant in ExoIL2-TAM. Enriched miR-375 could be transmitted between TAMs and HCC cells via exosomes and was responbible for the increased apoptosis of HCC cells. Conclusions: Taken together, IL-2 increases exosomal miR-375 from TAMs to attenuate hepatocellular carcinoma development. This study provides a new perspective to explain the mechanism how IL-2 inhibits hepatocellular carcinoma and implys the potential clinical value of exosomal miR-375 released by TAMs.