Dataset Information

KRAS mutation-induced upregulation of PD-L1 mediates immune escape in human lung adenocarcinoma.

ABSTRACT: It was reported that PD-L1 expression was correlated with genetic alterations. Whether PD-L1 was regulated by mutant Kirsten rat sarcoma viral oncogene homolog (KRAS) in non-small-cell lung cancer (NSCLC) and the underlying molecular mechanism were largely unknown. In this study, we investigated the correlation between PD-L1 expression and KRAS mutation and the functional significance of PD-1/PD-L1 blockade in KRAS-mutant lung adenocarcinoma. We found that PD-L1 expression was associated with KRAS mutation both in the human lung adenocarcinoma cell lines and tissues. PD-L1 was up-regulated by KRAS mutation through p-ERK but not p-AKT signaling. We also found that KRAS-mediated up-regulation of PD-L1 induced the apoptosis of CD3-positive T cells which was reversed by anti-PD-1 antibody (Pembrolizumab) or ERK inhibitor. PD-1 blocker or ERK inhibitor could recover the anti-tumor immunity of T cells and decrease the survival rates of KRAS-mutant NSCLC cells in co-culture system in vitro. However, Pembrolizumab combined with ERK inhibitor did not show synergistic effect on killing tumor cells in co-culture system. Our study demonstrated that KRAS mutation could induce PD-L1 expression through p-ERK signaling in lung adenocarcinoma. Blockade of PD-1/PD-L1 pathway may be a promising therapeutic strategy for human KRAS-mutant lung adenocarcinoma.

SUBMITTER: Chen N

PROVIDER: S-EPMC5579171 | biostudies-literature | 2017 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

KRAS mutation-induced upregulation of PD-L1 mediates immune escape in human lung adenocarcinoma.

Chen Nan N Fang Wenfeng W Lin Zhong Z Peng Peijian P Wang Juan J Zhan Jianhua J Hong Shaodong S Huang Jiaxing J Liu Lin L Sheng Jin J Zhou Ting T Chen Ying Y Zhang Hongyu H Zhang Li L

Cancer immunology, immunotherapy : CII 20170427 9

It was reported that PD-L1 expression was correlated with genetic alterations. Whether PD-L1 was regulated by mutant Kirsten rat sarcoma viral oncogene homolog (KRAS) in non-small-cell lung cancer (NSCLC) and the underlying molecular mechanism were largely unknown. In this study, we investigated the correlation between PD-L1 expression and KRAS mutation and the functional significance of PD-1/PD-L1 blockade in KRAS-mutant lung adenocarcinoma. We found that PD-L1 expression was associated with KR ...[more]

PMID: 28451792

Similar Datasets

Project description:BackgroundImmunotherapy has proven to be an emerging treatment for non-small-cell lung cancer in recent years. Notably, smokers show higher programmed cell death ligand-1 (PD-L1) expression and better responses to PD-1/PD-L1 inhibitors than nonsmokers. Genome-wide association studies show that the CHRNΑ5 encoding α5-nicotinic acetylcholine receptor (α5-nAChR) is especially relevant to lung cancer and nicotine dependence. Jab1 is a key regulatory factor and promotes the stabilization of PD-L1. Our previous study reported that α5-nAChR mediates lung adenocarcinoma (LUAD) epithelial-mesenchymal transition (EMT) and metastasis via STAT3/Jab1. However, the link between α5-nAChR and PD-L1 is unclear in LUAD.MethodsWe used various bioinformatics databases to analyze the expression of related genes and their correlations. Expression and clinicopathologic significance of α5-nAChR and PD-L1 were detected by immunohistochemistry in a tissue microarray. α5-nAChR regulated LUAD cell immune escape by targeting the STAT3/Jab1-PD-L1 signalling by Western-blotting and ChIP in vitro. We used T cell coculture, flow cytometry, ELISA, CCK8 assay and crystal violet staining to detect the expression of regulatory T cell (Tregs), IFN-γ, IL-2 and the ability of T cell-mediated tumour cell killing respectively. IF assays were performed in both cancer cells and tumour xenograft paraffin sections to analyze the protein expression. The in vivo experiments in mouse model were performed to show the α5-nAChR-mediated immune escape via PD-L1 pathway.ResultsThe expression of α5-nAChR was correlated with PD-L1 expression, smoking status and lower survival of LUAD in vivo. In vitro, the expression of α5-nAChR mediated phosphorylated STAT3 (pSTAT3), Jab1 and PD-L1 expression. STAT3 bound to the Jab1 or PD-L1 promoter and mediated PD-L1 expression. Jab1 stabilized PD-L1 expression in LUAD cells. Furthermore, in primary T cell cocultured system, downregulation of α5-nAChR suppressed the function of CD4+CD25+FOXP3+ Tregs, enhanced IFN-γ secretion, and increased T cell-mediated killing of LUAD cells. In the Jurkat T cells and LUAD cells coculture assay, inhibition of α5-nAChR increased IL-2 secretion. In tumour xenograft tissues, α5-nAChR expression was related to PD-L1, Jab1, pSTAT3, CD4 and granzyme B expression (GB).ConclusionsOur results suggest that the novel α5-nAChR/STAT3-Jab1-PD-L1 axis is involved in LUAD immune escape, which could lead to potential therapeutic strategies for cancer immunotherapy. Video abstract.

Project description:Tumor-infiltrating T cells are highly expressive of inhibitory receptor/immune checkpoint molecules that bind to ligand expressed by tumor cells and antigen-presenting cells, and eventually lead to T cell dysfunction. It is a hot topic to restore T cell function by targeting immune checkpoint. In recent years, immunotherapy of blocking immune checkpoint and its receptor, such as PD-L1/PD-1 targeted therapy, has made effective progress, which brings hope for patients with advanced malignant tumor. However, only a few patients benefit from directly targeting these checkpoints or their receptors by small compounds or antibodies. Since the complexity of the regulation of immune checkpoints in tumor cells, further research is needed to identify the novel endogenous regulators of immune checkpoints which can help for developing effective drug target to improve the effect of immunotherapy. Here, we verified that microRNA-326 (miR-326) repressed the gene expression of immune checkpoint molecules PD-L1 and B7-H3 in lung adenocarcinoma (LUAD). We detected that the expression of miR-326 in LUAD tissue was negatively correlated with PD-L1/B7-H3. The repression of PD-L1 and B7-H3 expression through miR-326 overexpression leads to the modification the cytokine profile of CD8+ T cells and decreased migration capability of tumor cells. Meanwhile, the downregulation of miR-326 promoted tumor cell migration. Moreover, blocking PD-L1 and B7-H3 attenuated the tumor-promoting effect induced by miR-326 inhibitor. In tumor-bearing mice, the infiltration of CD8+ T cells was significantly increased and the expression of TNF-α, and IFN-γ was significantly enhanced which contributed to tumor progression after miR-326 overexpression. Collectively, miR-326 restrained tumor progression by downregulating PD-L1 and B7-H3 expression and increasing T cell cytotoxic function in LUAD. Our findings revealed a novel perspective on the complex regulation of immune checkpoint molecules. A new strategy of using miR-326 in tumor immunotherapy is proposed.

Project description:A TLR9 agonist in combination with a PD-1 inhibitor produced powerful antitumor responses in a clinical trial despite TLR9 agonists as monotherapies failing to generate systemic antitumor immune responses due to immunosuppressive effects. However, the mechanism involved in the improved response induced by their combination remains unknown. Methods: Subcutaneous and orthotopic Hepa1-6 tumor model was used for single-drug and combined-drug treatment. We used TLR9 agonist stimulation or lentiviral vectors to overexpress TLR9 and activate TLR9 signaling. We next investigated the crosstalk between PARP1 autoPARylation and ubiquitination and between STAT3 PARylation and phosphorylation mediated by TLR9. Tissue chips were used to analyze the relationships among TLR9, PARP1, p-STAT3 and PD-L1 expression. Results: In this study, we found that the TLR9 agonist in combination with anti-PD-1 therapy or anti-PD-L1 therapy yielded an additive effect that inhibited HCC growth in mice. Mechanistically, we found that TLR9 promoted PD-L1 transcription by enhancing STAT3 Tyr705 phosphorylation. Then, we observed that TLR9 negatively regulated PARP1 expression, which mediated a decrease in STAT3 PARylation and an increase in STAT3 Tyr705 phosphorylation. Moreover, we found that TLR9 enhanced PARP1 autoPARylation by inhibiting PARG expression, which then promoted the RNF146-mediated ubiquitination and subsequent degradation of PARP1. Finally, we observed positive associations between TLR9 and p-STAT3 (Tyr705) or PD-L1 expression and negative associations between TLR9 and PARP1 in HCC patient samples. Conclusions: We showed that hepatoma cell-intrinsic TLR9 activation regulated the crosstalk between PARP1 autoPARylation and ubiquitination and between STAT3 PARylation and phosphorylation, which together upregulated PD-L1 expression and finally induces immune escape. Therefore, combination therapy with a TLR9 agonist and an anti-PD-1 antibody or anti-PD-L1 had much better antitumor efficacy than either monotherapy in HCC.

Dataset Information

KRAS mutation-induced upregulation of PD-L1 mediates immune escape in human lung adenocarcinoma.

Publications

KRAS mutation-induced upregulation of PD-L1 mediates immune escape in human lung adenocarcinoma.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets