title: Hypoxia-Induced Epithelial-to-Mesenchymal Transition in Hepatocellular Carcinoma Induces an Immunosuppressive Tumor Microenvironment to Promote Metastasis.
abstract: Portal vein tumor thrombosis (PVTT) is a significant risk factor for metastasis in hepatocellular carcinoma (HCC) patients and is therefore associated with poor prognosis. The presence of PVTT frequently accompanies substantial hypoxia within the tumor microenvironment, which is suggested to accelerate tumor metastasis, but it is unclear how this occurs. Recent evidence has shown that the hypoxia-inducible factor HIF-1α induces epithelial-to-mesenchymal transition (EMT) in tumor cells to facilitate metastasis. In this study, we investigated whether hypoxia-induced EMT in cancer cells also affects immune cells in the tumor microenvironment to promote immunosuppression. We found that hypoxia-induced EMT increased the expression of the CCL20 cytokine in hepatoma cells. Furthermore, coculture of monocyte-derived macrophages with hypoxic hepatoma cells revealed that the expression of indoleamine 2, 3-dioxygenase (IDO) was induced in monocyte-derived macrophages in a CCL20-dependent manner. In turn, these IDO-expressing monocyte-derived macrophages suppressed T-cell proliferation and promoted the expansion of immunosuppressive regulatory T cells. Moreover, high CCL20 expression in HCC specimens was associated with PVTT and poor patient survival. Collectively, our findings suggest that the HIF-1α/CCL20/IDO axis in hepatocellular carcinoma is important for accelerating tumor metastasis through both the induction of EMT and the establishment of an immunosuppressive tumor microenvironment, warranting further investigation into the therapeutic effects of blocking specific nodes of this signaling network.
authors.affiliation: Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, P.R. China. Key Laboratory of Cancer Prevention and Intervention, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, P.R. China.
authors.forename: Long-Yun
authors.initials: LY
authors.lastname: Ye
authors.affiliation: Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, P.R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.affiliation: Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, P.R. China. Key Laboratory of Cancer Prevention and Intervention, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, P.R. China.
authors.forename: Xue-Li
authors.initials: XL
authors.lastname: Bai
authors.affiliation: Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, P.R. China. Key Laboratory of Cancer Prevention and Intervention, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, P.R. China.
authors.forename: Xing-Yuan
authors.initials: XY
authors.lastname: Xu
authors.affiliation: Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, P.R. China. Key Laboratory of Cancer Prevention and Intervention, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, P.R. China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, P.R. China.
authors.forename: Xue-Feng
authors.initials: XF
authors.lastname: Xia
authors.affiliation: Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, P.R. China.
authors.forename: Xu
authors.initials: X
authors.lastname: Sun
authors.affiliation: Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, P.R. China.
authors.forename: Guo-Gang
authors.initials: GG
authors.lastname: Li
authors.affiliation: Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, P.R. China.
authors.forename: Qi-Da
authors.initials: QD
authors.lastname: Hu
authors.affiliation: Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, P.R. China.
authors.forename: Qi-Han
authors.initials: QH
authors.lastname: Fu
authors.affiliation: Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, P.R. China. Key Laboratory of Cancer Prevention and Intervention, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, P.R. China Collaborative Innovation Center for Cancer Medicine, Zhejiang University, Hangzhou, P.R. China. liangtingbo@zju.edu.cn.
authors.forename: Ting-Bo
authors.initials: TB
authors.lastname: Liang
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000401:mortality / Q000473:pathology*; D015687:Cell Hypoxia; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D018572:Disease-Free Survival; D058750:Epithelial-Mesenchymal Transition; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism*; D008113:Liver Neoplasms / Q000401:mortality / Q000473:pathology*; D009362:Neoplasm Metastasis; D015398:Signal Transduction; D059016:Tumor Microenvironment
chemical_list: D051795:Hypoxia-Inducible Factor 1, alpha Subunit