Wen Q, Han T, Wang Z, Jiang S. Role and mechanism of programmed death-ligand 1 in hypoxia-induced liver cancer immune escape.
Oncol Lett 2020;
19:2595-2601. [PMID:
32218809 PMCID:
PMC7068669 DOI:
10.3892/ol.2020.11369]
[Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Accepted: 10/10/2019] [Indexed: 12/24/2022] Open
Abstract
Immune escape plays a vital role in the development of liver cancer. The interaction between programmed death-ligand 1 (PD-L1) and programmed cell death-1 is a key mediator of cancer immune escape, which leads to the suppression of anticancer immunity and promotion of tumor progression. Hypoxia is a common phenomenon in the tumor microenvironment. Under hypoxic conditions, suppressive immune cells, such as regulatory T cells, myeloid-derived suppressor cells and M2 macrophages, are frequently recruited to tumor tissues to form the immunosuppressive microenvironment in liver cancer. These cells secrete cancer-promoting inflammatory cytokines, which activate the STAT3 and NF-κB signaling pathways. Recent studies have shown that STAT3 is associated with NF-κB and that these transcription factors are often co-activated to regulate tumor proliferation, survival, angiogenesis and invasion. The activation of STAT3 and NF-κB signaling pathways can directly and indirectly induce PD-L1 expression. Therefore, further understanding of the association between hypoxia and PD-L1 may help in the future treatment of liver cancer. The present review summarizes the recent progresses on PD-L1-mediated regulation and facilitation of liver cancer cell immune escape in response to hypoxia.
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