Exosomes from Melatonin Treated Hepatocellularcarcinoma Cells Alter the Immunosupression Status through STAT3 Pathway in Macrophages.
Immunosuppression is a significant factor in the progression of tumor invasion and metastasis. Melatonin, a well-known hormone, has certain cytotoxic and immune regulatory effects to inhibit tumor function. Exosomes are small membrane vesicles released by many kinds of cells, which contain different macromolecules, such as mRNAs and microRNAs (miRNAs), and proteins that can mediate communications between cells. Tumor-derived exosomes may cause immunosuppression, however, it is unknown whether melatonin can attenuate an immunosuppressive status by altering the function of tumor-derived exosomes. In the present study, we evaluated the effects of hepatocellularcarcinoma-derived exosomes (Exo-con) and exosomes derived from hepatocellularcarcinoma cells treated with 0.1 mM melatonin (Exo-MT), on the expression of inflammatory factors and programmed death ligand 1(PD-L1) by co-culturing Exo-con and Exo-MT, respectively, with macrophages differentiated from THP-1 cells or RAW264.7 cells. Our in vitro results indicate that Exo-MT can downregulate the expression of PD-L1 on macrophages while Exo-con can upregulate the expression of PD-L1 through flow cytometry and immunofluorescence analysis. In addition, Exo-con upregulates the secretion of cytokines, such as IL-6, IL-10, IL-1β, and TNF-α in macrophages. Accordingly, Exo-MT could attenuate the high expression of these inflammatory cytokines. Furthermore, in vivo experiments confirmed the results found in vitro. PD-L1 expression and cytokine secretion were lower in the Exo-MT group compared with those in the Exo-con group. Working to identify a specific mechanism, our research shows that Exo-MT decreases STAT3 activation compared to the Exo-con group. In summary, we found exosomes from melatonin treated hepatocellularcarcinoma cells alters the immunosupression status through STAT3 pathway in macrophages. Our study may provide a new avenue to investigate the mechanisms of melatonin in regulating an immunosuppressive status.
['Cheng|Liang|L|', 'Liu|Jiatao|J|', 'Liu|Qingqing|Q|', 'Liu|Yu|Y|', 'Fan|Lulu|L|', 'Wang|Fang|F|', 'Yu|Hanqing|H|', 'Li|Yuhuan|Y|', 'Bu|Lijia|L|', 'Li|Xiaoqiu|X|', 'Wei|Wei|W|', 'Wang|Hua|H|', 'Sun|Guoping|G|']
D000818:Animals D060890:B7-H1 Antigen D015153:Blotting, Western D006528:Carcinoma, Hepatocellular D045744:Cell Line, Tumor D055354:Exosomes D005260:Female D005434:Flow Cytometry D015972:Gene Expression Regulation, Neoplastic D006801:Humans D007150:Immunohistochemistry D016753:Interleukin-10 D015850:Interleukin-6 D008264:Macrophages D008550:Melatonin D051379:Mice D008807:Mice, Inbred BALB C D008819:Mice, Nude D046529:Microscopy, Electron, Transmission D050796:STAT3 Transcription Factor D000074084:THP-1 Cells D014409:Tumor Necrosis Factor-alpha
exosomes melatonin PD-L1 cytokines macrophages. Hepatoma cell