OBJECTIVE Programmed death ligand-1(PD-L1)and indoleamine 2,3-dioxygenase 1(IDO1)are immune checkpoints which can be induced by interferon-γ(IFN-γ)in the tumor microenvironment,leading to immune escape of tumors.Myr...OBJECTIVE Programmed death ligand-1(PD-L1)and indoleamine 2,3-dioxygenase 1(IDO1)are immune checkpoints which can be induced by interferon-γ(IFN-γ)in the tumor microenvironment,leading to immune escape of tumors.Myricetin(MY)is a flavonoid distributed in many edible and medicinal plants.The aim of this study is to clarify the effect and the mechanism of MY on inhibiting IFN-γ-induced PD-L1 and IDO1 in lung cancer cells.METHODS Expressions of PD-L1 and major histocompatibility complex-I(MHC-I)were evaluated by flow cytometry and Western blotting,and the expression of IDO1 was measured by Western blotting.qRT-PCR was used to detect their mRNA levels.The function of T cells was evaluated using a co-culture system consist of lung cancer cells and the Jurkat-PD-1 T cell line that overexpressing PD-1.Molecular docking analysis,Western blotting and immunofluorescence were used for mechanism study.RESULTS MY potently inhibited IFN-γ-induced PD-L1 and IDO1 expression in human lung cancer cells,while didn't show obvious effect on the expression of MHC-I.In addition,MY restored the survival,proliferation,CD69 expression and interleukin-2(IL-2)secretion of Jurkat-PD-1 T cells suppressed by IFN-γ-treated lung cancer cells in the co-culture system.Mechanistically,IFN-γup-regulated PD-L1 and IDO1 at the transcriptional level through the JAK-STAT-IRF1 axis,which was targeted and inhibited by MY.CONCLUSION Our research revealed a new insight into the anti-tumor effects of MY which inhibited IFN-γ-induced PD-L1 and IDO1 expression,supporting the potential of MY in anti-tumor immunotherapy.展开更多
Nagilactone E(NLE),a natural product with anticancer activities,is isolated from Podocarpus nagi.In this study,we reported that NLE increased programmed death ligand 1(PD-L1)expressions at both protein and mRNA levels...Nagilactone E(NLE),a natural product with anticancer activities,is isolated from Podocarpus nagi.In this study,we reported that NLE increased programmed death ligand 1(PD-L1)expressions at both protein and mRNA levels in human lung cancer cells,and enhanced its localization on the cell membrane.Mechanistically,NLE increased the phosphorylation and expression of cJun,and promoted the localization of c-Jun in the nucleus,while silencing of c-Jun by small interfering RNA(siRNA)reduced NLEinduced PD-L1.Further study showed that NLE activated the c-Jun N-terminal kinases(JNK),the upstream of c-Jun,and its inhibitor SP600125 reversed the NLE-increased PD-L1.Moreover,NLE-induced PD-L1 increased the binding intensity of PD-1 on the cell surface.In summary,NLE upregulates the expression of PD-L1 in lung cancer cells through the activation of JNK-c-Jun axis,which has the potential to combine with the PD-1/PD-L1 antibody therapies in lung cancer.展开更多
基金Science and Technology Development Fund,Macao SAR(0129/2019/A3176/2017/A3)and University of Macao(MYRG2018-00165-ICMS)。
文摘OBJECTIVE Programmed death ligand-1(PD-L1)and indoleamine 2,3-dioxygenase 1(IDO1)are immune checkpoints which can be induced by interferon-γ(IFN-γ)in the tumor microenvironment,leading to immune escape of tumors.Myricetin(MY)is a flavonoid distributed in many edible and medicinal plants.The aim of this study is to clarify the effect and the mechanism of MY on inhibiting IFN-γ-induced PD-L1 and IDO1 in lung cancer cells.METHODS Expressions of PD-L1 and major histocompatibility complex-I(MHC-I)were evaluated by flow cytometry and Western blotting,and the expression of IDO1 was measured by Western blotting.qRT-PCR was used to detect their mRNA levels.The function of T cells was evaluated using a co-culture system consist of lung cancer cells and the Jurkat-PD-1 T cell line that overexpressing PD-1.Molecular docking analysis,Western blotting and immunofluorescence were used for mechanism study.RESULTS MY potently inhibited IFN-γ-induced PD-L1 and IDO1 expression in human lung cancer cells,while didn't show obvious effect on the expression of MHC-I.In addition,MY restored the survival,proliferation,CD69 expression and interleukin-2(IL-2)secretion of Jurkat-PD-1 T cells suppressed by IFN-γ-treated lung cancer cells in the co-culture system.Mechanistically,IFN-γup-regulated PD-L1 and IDO1 at the transcriptional level through the JAK-STAT-IRF1 axis,which was targeted and inhibited by MY.CONCLUSION Our research revealed a new insight into the anti-tumor effects of MY which inhibited IFN-γ-induced PD-L1 and IDO1 expression,supporting the potential of MY in anti-tumor immunotherapy.
基金supported by the Science and Technology Development Fund,Macao SAR(No.176/2017/A3)University of Macao(No.MYRG2018-00165-ICMS/CPG.020-00016-ICMS/MYRG2017-00109-ICMS)。
文摘Nagilactone E(NLE),a natural product with anticancer activities,is isolated from Podocarpus nagi.In this study,we reported that NLE increased programmed death ligand 1(PD-L1)expressions at both protein and mRNA levels in human lung cancer cells,and enhanced its localization on the cell membrane.Mechanistically,NLE increased the phosphorylation and expression of cJun,and promoted the localization of c-Jun in the nucleus,while silencing of c-Jun by small interfering RNA(siRNA)reduced NLEinduced PD-L1.Further study showed that NLE activated the c-Jun N-terminal kinases(JNK),the upstream of c-Jun,and its inhibitor SP600125 reversed the NLE-increased PD-L1.Moreover,NLE-induced PD-L1 increased the binding intensity of PD-1 on the cell surface.In summary,NLE upregulates the expression of PD-L1 in lung cancer cells through the activation of JNK-c-Jun axis,which has the potential to combine with the PD-1/PD-L1 antibody therapies in lung cancer.
