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Zhao J, Li H, Zhao S, Wang E, Zhu J, Feng D, Zhu Y, Dou W, Fan Q, Hu J, Jia L, Liu L. Epigenetic silencing of miR-144/451a cluster contributes to HCC progression via paracrine HGF/MIF-mediated TAM remodeling. Mol Cancer 2021; 20:46. [PMID: 33658044 PMCID: PMC7927270 DOI: 10.1186/s12943-021-01343-5] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 02/23/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND & AIMS Hepatocellular carcinoma (HCC) is among the malignancies with the highest mortality. The key regulators and their interactive network in HCC pathogenesis remain unclear. Along with genetic mutations, aberrant epigenetic paradigms, including deregulated microRNAs (miRNAs), exert profound impacts on hepatocyte transformation and tumor microenvironment remodeling; however, the underlying mechanisms are largely uncharacterized. METHODS We performed RNA sequencing on HCC specimens and bioinformatic analyses to identify tumor-associated miRNAs. The miRNA functional targets and their effects on tumor-infiltrating immune cells were investigated. The upstream events, particularly the epigenetic mechanisms responsible for miRNA deregulation in HCC, were explored. RESULTS The miR-144/miR-451a cluster was downregulated in HCC and predicted a better HCC patient prognosis. These miRNAs promoted macrophage M1 polarization and antitumor activity by targeting hepatocyte growth factor (HGF) and macrophage migration inhibitory factor (MIF). The miR-144/miR-451a cluster and EZH2, the catalytic subunit of polycomb repressive complex (PRC2), formed a feedback circuit in which miR-144 targeted EZH2 and PRC2 epigenetically repressed the miRNA genes via histone H3K27 methylation of the promoter. The miRNA cluster was coordinately silenced by distal enhancer hypermethylation, disrupting chromatin loop formation and enhancer-promoter interactions. Clinical examinations indicated that methylation of this chromatin region is a potential HCC biomarker. CONCLUSIONS Our study revealed novel mechanisms underlying miR-144/miR-451a cluster deregulation and the crosstalk between malignant cells and tumor-associated macrophages (TAMs) in HCC, providing new insights into HCC pathogenesis and diagnostic strategies.
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Affiliation(s)
- Junlong Zhao
- State Key Laboratory of Cancer Biology, Department of Medical Genetics and Development Biology, Fourth Military Medical University, Xi'an, 710032, China
| | - Huichen Li
- State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, School of Basic Medicine, Fourth Military Medical University, No.169 Changlexi Road, Xi'an, 710032, China
| | - Shoujie Zhao
- Department of General Surgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, 710038, China
| | - Enxin Wang
- Department of Gastroenterology, Tangdu Hospital of the Fourth Military Medical University, No.569 Xinsi Road, Xi'an, 710038, China
| | - Jun Zhu
- State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, School of Basic Medicine, Fourth Military Medical University, No.169 Changlexi Road, Xi'an, 710032, China
| | - Dayun Feng
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, 710038, China
| | - Yejing Zhu
- Department of General Surgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, 710038, China
| | - Weijia Dou
- Department of Gastroenterology, Tangdu Hospital of the Fourth Military Medical University, No.569 Xinsi Road, Xi'an, 710038, China
| | - Qingling Fan
- Department of Gastroenterology, Tangdu Hospital of the Fourth Military Medical University, No.569 Xinsi Road, Xi'an, 710038, China
| | - Jie Hu
- Department of Gastroenterology, Tangdu Hospital of the Fourth Military Medical University, No.569 Xinsi Road, Xi'an, 710038, China
| | - Lintao Jia
- State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, School of Basic Medicine, Fourth Military Medical University, No.169 Changlexi Road, Xi'an, 710032, China.
| | - Lei Liu
- Department of Gastroenterology, Tangdu Hospital of the Fourth Military Medical University, No.569 Xinsi Road, Xi'an, 710038, China. .,Department of Cell Biology, Fourth Military Medical University, No.169 Changlexi Road, Xi'an, 710032, China.
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