Tim-3 fosters HCC development by enhancing TGF-β-mediated alternative activation of macrophages. Issue 10 (21st January 2015)

• Record Type: Journal Article
• Authors: Yan, Wenjiang; Liu, Xiao; Ma, Hongxin; Zhang, Hualin; Song, Xiaojia; Gao, Lifen; Liang, Xiaohong; Ma, Chunhong
• Is Part Of: Gut. Volume 64:Issue 10(2015)
• Page Start: 1593
• Page End: 1604
• Publication Date: 2015-01-21
• Subjects: CANCER IMMUNOBIOLOGY -- KUPFFER CELL -- HEPATOMA -- MOLECULAR IMMUNOLOGY -- TGF-BETA; Gastroenterology -- Periodicals; 616.33
• DOI: 10.1136/gutjnl-2014-307671
• Languages: English
• ISSNs: 0017-5749

Abstract

Abstract : Objective: Tumour-associated macrophages (TAMs) and their alternative activation contribute greatly to the development of hepatocellular carcinoma (HCC). Tim-3 is highly expressed on macrophages and regulates macrophage functions in several conditions. However, whether Tim-3 is involved in the activation and the function of TAMs has not been reported. Design: Tim-3 expression in HCC samples was evaluated by flow cytometry, immunohistochemistry and confocal analysis. We analysed the effects of Tim-3 knockdown on macrophages in growth of H22 tumour homografts in BALB/c mice. Tim-3 interference was performed by neutralising antibody, small interfering RNA or short hairpin RNA-expressing lentivirus. Cytokine production was evaluated by reverse transcription PCR, ELISA or Cytometric Bead Array. The effects of Tim-3 interference in macrophages were examined with regard to alternative activation of macrophages and proliferation and migration of Hepa1-6 cells. Cell growth curve, colony formation and transwell assays were involved to estimate cell proliferation and migration. Results: Tim-3 expression was significantly increased in both peripheral blood monocytes and TAMs in patients with HCC. The Tim-3 expression in monocytes/TAMs strongly correlated with higher tumour grades and the poor survival of patients with HCC. Consistently, HCC conditioned medium or transforming growth factor-β fostered Tim-3 expression and the alternative activation of macrophages. Moreover, Tim-3 interference in macrophages significantly inhibited the alternative activation of macrophages and suppressed HCC cell growth both in vitro and in vivo. Blocking interleukin 6 reversed the Tim-3-mediated effects on HCC cell growth in vitro. Conclusions: Tim-3 displays critical roles in microenvironment-induced activation and protumoral effects of TAMs in HCC. Interference of Tim-3 might be great potential in HCC therapy.